Eating the Right Food Free Essays

string(108) " time there is not a big variety of local foods that you can buy, because of the severe weather conditions\." â€Å"You are what you eat† said for the first time Anthelme Brillat-Savarin back in 1826 and since then this phrase is being used a lot by nutritionists. If this is really true, then a lot of Americans would appear to be unhealthy, treated with chemicals and, commercially raised animal flesh. While this does not sound very nice, it is nonetheless a description of the typical Americans who survive on the consumption of big macs and greasy French fries. We will write a custom essay sample on Eating the Right Food or any similar topic only for you Order Now â€Å"Unfortunately, studies show that over eighty five percent of Americans no longer eat even one meal at home together every day† (Bond, 4). It is true, and what should the average Americans do about this problem? They should better choose what they eat. Eating the right food is like getting an A at school. If you eat right food you will most likely be healthy. If you are getting A’s at school, you will most likely be successful. Eating the right food will contribute to your healthy living. By making the right choices, you will help yourself avoid some very serious problems. Making poor choices like eating too much wrong food, increases your chances of developing cancer, heart disease, diabetes, digestive disorders and aging related loss of vision. An example for that is the obesity, which is a major health concern in the United States. â€Å"Obesity can be linked to some 300,000 deaths and $117 billion in health care costs a year† (Espejo, 11). This statistics is very scary and it shows us how serious can be the wrong choice of our food. If we want to live healthy, we have to eat right. Eating the right food is not a hard thing to do. We just have to know some basic rules. One way to choose the right food is to follow the Food Guide Pyramid, developed by The Ivanova 2 United States Department of Agriculture (USDA). More than one hundred years ago in 1894, the USDA published its first food guide, where the author, a nutritionist, introduced the idea of food groups. The five food groups defined in the food guide were milk and meat, cereals, fruits and vegetables, fats and fatty foods, and sugars and sugary foods. The guide made recommendations about eating food from each food group to remain healthy. MyPyramid is the most recent food guide, designed to provide Americans with a wide variety of food recommendations that will promote their health. MyPyramid was a major revision of the Food Guide Pyramid. It was designed to illustrate recommendations found in the Dietary Guidelines for Americans 2005 released by the USDA in January 2005. MyPyramid is intended to help Americans choose the right food to eat. It is designed to help people learn how to eat a healthy diet and live an active lifestyle. The latest food pyramid makes recommendations in seven categories: grains, vegetables, fruits, milk, meat and beans, oils, discretionary calories, and Ivanova 3 physical activity. Each food category is a different color in the pyramid with different recommendations. The highest recommendation according to the pyramid is for grains, milk and vegetables. The lowest recommendation is for oils and meat. MyPyramid assumes that people will eat from all food categories. I have found that following MyPyramid is the simplest way of balancing my meals. It separates foods into groups and graphs the amount of each group needed in an average person’s diet. The second way to choose the right food is to eat local and seasonal food. Eating local food has a lot of advantages. The shorter the distance that food travels from farm to table, the better. The long-distance transport of food requires more preservatives, packaging, refrigeration and fuel. By purchasing local foods in-season, you eliminate the environmental damage caused by shipping foods thousands of miles, your money spent on food goes directly to the farmer, and your family will be able to enjoy the health benefits of eating fresh, unprocessed fruits and vegetables. Eating locally does not mean to give up products like coffee and tea, which are grown only in certain regions. But it does mean to make choices when possible in favor of those foods that are produces near you. â€Å"Get out of the supermarket whenever you can† (Pollan, 33) is one of the Michael Pollan’s food rules. This rule implies the importance of going to the local farmer’s market. In the farmer’s market you will find fresh whole foods picked at the peak of nutritional quality. You will find food that â€Å"your great-great-grandmother would have recognized as food† (Pollan, 7). There are a lot of programs that try to promote growing fresh produce. South Central Los Angeles’ â€Å"Food from the Hood† program has brought ttention to the potential of its embattled Crenshaw district, while providing with Ivanova 4 college funds for the high school students who maintain organic gardens. San Francisco’s Fresh Start Farms employs homeless families to grow produce forthe city’s many restaurants. And U. S. prisons have taken to garden ing projects in a big way, like San Francisco County Jail’s Garden Project, which has prisoners growing food for local soup kitchens† (Motavalli, 17). These programs are great examples of promoting growing fresh and organic food. But that should embrace a larger number of people engaged with growing fresh produce. Not only homeless people, prisoners and students. Different programs should be developed in larger areas, where people can join and help grow fresh and organic food. Try to eat most foods only when they are in season, or can seasonal food in order to eat and enjoy it all year round. Buying seasonal produce also provides an opportunity to try new foods and to experiment with seasonal recipes. And it simply tastes better! Every region of the world has its harvest seasons. In order to eat locally, we have to be familiar with what is local and seasonal in the area we live. For example, in my country Bulgaria in winter time there is not a big variety of local foods that you can buy, because of the severe weather conditions. You read "Eating the Right Food" in category "Papers" So we usually buy bananas and oranges, that are imported. But in spring, where everything comes to life, we start buying strawberries and cherries. I was not used to eat strawberries all over the year before, because in my country we grow strawberries only in spring and this is the only time of the year that you can buy and eat strawberries. Here you can buy strawberries any time of the year, but I do not do that, because they do not taste good. In summer time in Bulgaria we buy peaches, apricots, tomatoes, corn and a lot more. In California on the other hand, in winter we can enjoy grapefruits, lemons, oranges, lettuce, mushrooms, and potatoes. An important part of buying local is making an effort to purchase fresh fruits and vegetables when they are in season in your area. Although today’s global marketplace allows us to buy foods grown virtually anywhere in the world all year round, these options are not the most sustainable. Even if you do not want to change any of your eating habits, you can at least make sure to buy local produce when it’s available, rather than purchase the same type of food from three thousand miles away! The third way to choose the right food is to eat fresh food and a lot of fruits and vegetables. Fresh food comes out of the ground and comes to your plate with as little interference as possible. The freshest produce is what you grow yourself and pick just before you eat it. Eating fresh food is as simple as it sounds. It does not mean avoiding frozen or canned food, but it rather means to eat food as close to its natural state as possible. Frozen foods and vegetables are nearly as good as fresh ones and they may even be more nutritious than fresh fruits and vegetables that have been stored for weeks or months under conditions that prevent ripening. Canned fruits and vegetables are usually fine, though many come loaded with salt and added sugar. (Willet, 126). â€Å"Eat plenty of fruits and vegetables† (Willet, 114). As child you hated to hear it. As a teenager, you promised yourself you would never say it to your children. This wisdom however is passed from generation to generation. This is a timeless advice, simple and easy to remember. The National Cancer Institute recommends that each of us eats at least five servings of fresh fruits and vegetables a day, since they play a very beneficial role in protecting against cancer, heart disease and other health problems. But what exactly are fruits and vegetables? â€Å"To a botanist, a fruit is any plant part that contains seeds, any by process of elimination, a vegetable is everything else: leaves, stems, flowers, roots and bulbs† (Willet, 115). The reason experts recommend so many servings of fruits and vegetables is that they offer the best way to prevent chronic diseases such as diabetes and cancer. We should simply â€Å"Eat food† (Pollan, 5). It is easy to say, but hard to do, especially with all the new food products that are introduced annually to the market. Most of these items do not even deserve to be call food. They consist mostly of ingredients derived from corn and soy that no normal person keeps in their pantry. Lastly, the right food to eat will be anything, but fast food. Most people choose fast food because it is convenient, fast, and cheap. Fast restaurants are everywhere, on every corner. They always have the best deals for food. Everything seems so delicious and in most of the times it is really delicious. But the problem is that is not healthy and this is absolutely the worse choice of food that we can make. â€Å"It’s not food if it arrived through the window of your car† (Pollan, 43). Fast food cannot be called food. We should avoid fast food restaurants if we care at least a little bit about ourselves. There is almost always a healthier choice. It may not be the cheapest or the fastest route, but I think that overall nutrition is more important than the thickness of our wallet. Cost, convenience, and lack of time all contribute to the bad eating habits most people have. Not everyone can afford to eat well in America, which is shameful, but most of us can. â€Å"Americans spend, on average, less than 10 percent of their income on food, down from 24 percent in 1947, and less than the citizens of any other nation†(The New York Times, January, 28, 2007). And those of us who can afford to eat well should. Paying more for the right food will contribute not only to your health also to the health of others who might not themselves be able to afford that sort of food: the people who grow it in the farms. Planning what to eat can eliminate impulse and over eating. In conclusion, choosing the right food to eat is not always easy. These are different ways to choose better our food. Choosing the right food to eat is choosing a better life. When we choose better our food we contribute actively to our health and to our life. MyPyramide is one way to choose the right food to eat. It gives us an idea how to balance the food we eat and what food to eat more and what to eat less. Another way to make a better food choice is eating a local and seasonal food. This is also not a very hard thing to do. We just have to make a little research on the local farmer’s markets and what kind of produce is grown seasonally in the area we live. The third way is to eat fresh produce and as many fruits and vegetables as possible. The last and maybe the most important thing to eat right is to avoid fast food. These are easy steps to living a happy, healthy and right life. How to cite Eating the Right Food, Papers

Conceptual Design of Short Takeoff Supersonic Aircraft with Cold Flow Nozzles free essay sample

International Conference on Trends in Mechanical and Industrial Engineering (ICTMIE2013) January 8-9, 2013 Kuala Lumpur (Malaysia) Conceptual Design of Short Takeoff Supersonic Aircraft with Cold Flow Nozzles Vignesh. M 1, Sathish. K1, Adrin Issai Arasu. L1, Dharun Lingam. K1, and Sanal Kumar. V. R 2 consumption and poor range) in turn making it unprofitable for manufacturers to produce these kinds of aircraft. It can cover a distance from India to USA in 2 ? hours. Propulsion systems that provide aircraft with the capability of both vertical and conventional forward flight represent a formidable challenge to the engine designer. Vertical and short takeoff and landing (V/STOL) aircraft have several major categories of engine arrangement. Some of the typical arrangements for high speed aircraft are: the engines may be fixed in a position required to produce thrust for forward flight. Their exhaust systems, however, have built-in variable geometry, making it possible to vector the exhaust nozzle (or nozzles) or divert the exhaust gases by means of valves and auxiliary ducts to nozzles mounted in such a way as to provide vertical thrust or lift. Another option is the aircraft may include two different sets of engines or propulsors (or both), fixed in position, with one set installed for forward flight and the other for vertical thrust (i. e. , the lift engines). Additionally, the aircraft may use a convertible engine. Supersonic aircraft usually use low bypass turbofans as they give good efficiency below the speed of sound as well as above, or if extended super cruise is needed turbojet engines are desirable as they give less nacelle drag at supersonic speeds. A supersonic transport (SST) is a civil aircraft designed to transport passengers at speeds greater than the speed of sound. The only supersonic civilian aircraft to see service are the Soviet produced Tupolev Tu-144 which first flew in 1968 and was retired in 1997, and the Franco-British produced Concorde, which first flew in 1969 and remained in service until 2003. Following the cessation of flying by Concorde in 2003, there are no supersonic civilian aircraft in service. These are succinctly reported in the open literature, which triggered the researchers to make attempts for unconventional lucrative design challenges of supersonic aircraft. In an attempt to resolve some of the technological challenges on supersonic aircraft design, a substantial revision of the existing concept is required. In this paper critical review of the literature is carried out and a conceptual design of short takeoff supersonic aircraft with cold flow multi-purpose rectangular nozzle has been proposed. Bachelor of Engineering Final Year Student, Department of Aeronautical Engineering, Kumaraguru College of Technology, Coimbatore – 641 049, Tamil Nadu, India (email: vignesh. [emailprotected] com) 2 Professor and Aerospace Scientist (ISRO), Aeronautical Engineering, Kumaraguru College of Technology, Coimbatore – 641 049, Tamil Nadu, India; Corresponding Author, (phone: +91 9150891021 / +91-9388679565, (email: [emailprotected] co. in) 1 Abstract— In this paper numerical studies have been carried out for the conceptual design of short takeoff supersonic aircraft with cold flow nozzles. As a first step supersonic rectangular CD nozzle with multi-purpose frame is designed in such a way that during the early taxiing time the internal flow choking will be established without forming any shockwave in the divergent region for facilitating the aircraft for a smooth and short takeoff. Immediately after the takeoff the nozzle frame will be converted into rectangular supercritical wing for meeting the high speed aerodynamic design objectives. Parametric analytical studies have been carried out for both internal and external flows using suitable turbulence models. The results from the parametric study indicate that cold flow choked nozzles with conventional jet engines will compliment for the short takeoff of supersonic aircraft lucratively without having any additional propulsion systems. Keywords— Choked Rectangular Nozzle, Rectangular Supercritical Airfoil, Short Takeoff Aircraft, Supersonic Aircraft. I. INTRODUCTION HE great majority of supersonic aircraft today are military or experimental aircraft. Most of them, including many military fighter aircraft, are designed to exceed the speed of sound only in certain exceptional flight regimes; a handful of aircraft, such as the SR-71 Blackbird military reconnaissance aircraft and the Concorde supersonic civilian transport, are designed to cruise continuously at speeds above the speed of sound. Supersonic flight brings with it substantial technical challenges, as the aerodynamics of supersonic flight are dramatically different from those of subsonic flight. These challenges have largely been met. However, political, environmental, and economic obstacles of greater magnitude continue to severely limit the actual deployment of supersonic aircraft, particularly in the civilian world. Additionally, the need and demand for supersonic flight have often been insufficient to justify development or deployment of supersonic aircraft, particularly in the domain of civilian transport. The aforementioned SR-71 and Concorde aircraft are no longer flying today although Concorde was highly profitable in service, but because of the low market among operators (due to sonic booms, relatively high fuel T Comparisons of 3D computation and experiment for non axi-symmetric nozzles have been carried out by NASA in 1989 [1]. The configurations are selected from a set of the single expansion ramp nozzles which were experimentally investigated by Re and Leavitt [2]. The experiments were performed to analyze the effects of various geometrical 256 3rd International Conference on Trends in Mechanical and Industrial Engineering (ICTMIE2013) January 8-9, 2013 Kuala Lumpur (Malaysia) parameters and pressure ratios on the static performance of these asymmetric nozzles. Three-dimensional solutions obtained with their code have been presented for two asymmetric, single expansion ramp nozzles at a pressure ratio of 10. The computed flow consists of the internal expansion region in the converging / diverging sections and the external supersonic exhaust in a quiescent ambient environment. The fundamental characteristics existing at the prescribed flow condition have been captured successfully for the present nozzle / exhaust flow field. These features include expansion fans, Mach wave reflections, mixing layers, and nonsymmetrical, multiple inviscid cell, supersonic exhausts. Comparison has been made with experimental data for wall pressure distributions at the center planes with good agreement. Applications of numerical methods to the nozzle complex flow field have been reported by investigators. Some of these studies have focused on the interaction of the exhaust plume and the external stream, and the consequent effects on the nozzle afterbody [3, 4]. In several other studies, the jet plume has been analyzed independently [5, 6]. The flow inside the nozzle is treated as a separate problem, and is generally well understood for a simple two-dimensional symmetrical nozzle. In the case of the nozzle considered in this paper, however, the independent treatment of the exhaust plume may not be adequate, since the initial part of the exhaust plume bordered by its free shear layer can change the flow structure near the upper external expansion surface. Simultaneously solving the flow field to account for the strongly interactive nature thus becomes necessary. Works related to this type of nozzle, in which the computations include a complete domain of the internal nozzle, the external exhaust plume and the ambient stream, have been performed by several other investigators [710]. Independent calculation of a similar nozzle had also been reported for a two-dimensional case [11]. Other results based on the full Navier- Stokes (NS) equations, parabolized NavierStokes (PNS) equations or method of characteristics in two and three dimensions have been calculated for a variety of nozzle conditions including supersonic, subsonic and quiescent external streams [12-16]. In addition, these previous analyses have demonstrated the simplicity of the simulation procedures as applied to the nozzle / exhaust problem, in which the geometry is complex and the flow is highly nonuniform. The importance of investigating rectangular turbulent jets is determined by both their practical importance and ? ow complexity. In fact, a rectangular turbulent jet is a typical example of a 3D turbulent ? ow, which is strongly influenced by initial conditions. Several papers have been written on rectangular turbulent jets [17-21]. It is difficult to compare the experimental data presented in these papers because of the considerable difference between the particular initial conditions, including the nozzle geometry and the experimental set-up itself. Hence it is almost impossible to summarize the results obtained by different authors. In addition most papers treat a particular geometry and specific initial conditions without investigating their influence. It should be noted that in recent years the number of publications on this topic has increased because of the need to 257 investigate the turbulent structure of the flow for various practical applications [21]. III. CONCEPTUAL DESIGN Turbulent jet flows issuing from rectangular nozzles are used in many technological and practical applications. Understanding their development and mechanics is important to the design and performance improvement of these applications. Therefore, rectangular jets have been Fig. 1 Supersonic aircraft with rectangular CD nozzle with adjustable frame facilitated for converting it into the rectangular supercritical airfoil after takeoff. studied extensively over the past decades. Fig. 1 shows the proposed design of military aircraft with CD rectangular nozzle under the wing and shifted laterally. A rectangular CD nozzle is an altered type of a De Laval nozzle where we can have reduced frontal surface area. Fig. 2(a-b) represents the physical model of a rectangular CD nozzle. The ultimate idea of this study is to reduce the take-off distance. Note that by placing the CD nozzle under the wing we can accelerate the cold flow at the choked flow condition during taxiing, resulting the sudden increase in thrust and short take-off. Though the idea is very simple the design optimisation of a rectangular CD nozzle is a difficult task. In order to control how much mass is moving and how fast it moves, the ratio of the exit to the throat is the key design component of a CD nozzle. In the divergent session of the CD nozzle the supersonic flow accelerates as the area gets bigger. This region of supersonic acceleration is terminated by a normal shock wave. (a) Physical Model b) Idealized Physical Model Fig. 2 (a-b) Physical models of the rectangular CD nozzle. 3rd International Conference on Trends in Mechanical and Industrial Engineering (ICTMIE2013) January 8-9, 2013 Kuala Lumpur (Malaysia) The shock wave produces a near-instantaneous deceleration of the flow to subsonic speed. This shock wave is the major concern in designing a CD nozzle. The size of the nozzle throat effectively sets the mass flow rate through the nozzle. Next, the area of the exit is important because it will determine how much the fluid is allowed to expand. This expansion will then determine the Mach number of the exiting flow. It also determines the exit pressure, temperature, and velocity of the fluid coming out. The proposed CD nozzle is an over expanded nozzle with P b /P c value of 0. 6 which will cause the flow to choke and will reduce the possibility of forming shock waves within the nozzle. Immediately after the takeoff it is proposed to transform the CD rectangular nozzle into a rectangular supercritical wing for reducing the wave drag during the transonic regime. IV. NUMERICAL METHOD OF SOLUTION Numerical simulations for internal flow have been carried out with the help of a two-dimensional standard k-epsilon model. It is a two equation turbulence model in which the solution of two separate transport equations allows the turbulent velocity and length scales to be independently determined. The turbulence kinetic energy, k, and its rate of dissipation, ? , are obtained from the following transport equations: (a) 3D Grid system (b) 2D Grid system Fig. 3(a-b) Grid systems in the computational domain of the rectangular CD nozzle. and G k represents the generation of turbulence kinetic energy due to the mean velocity gradients. G b is the generation of turbulence kinetic energy due to buoyancy. Y M represents the contribution of the fluctuating dilatation in compressible turbulence to the overall dissipation rate. C 1? , C 2? , and C 3? are constants. ? k and ? ? are the turbulent Prandtl numbers for k and ? , respectively. S k and S ? are user-defined source terms. Compressibility effects are encountered in gas flows at high velocity and/or in which there are large pressure variations. When the flow velocity approaches or exceeds the speed of sound or when the pressure change in the system is large, the variation of the gas density with pressure has a ignificant impact on the flow velocity, pressure, and temperature. Compressible flows create a unique set of flow physics for which one must be aware of the special input requirements and appropriate solution techniques. Compressible flows are typically characterized the total pressure P o and total temperature T o of the flow. In this model the compressible flows are described by the standard continuity and momentum equation s with the inclusion of the compressible treatment of the density. The energy equation solved by the code will incorporate the coupling between the flow velocity and the static temperature. The viscosity is determined from the Sutherland formula. All boundary conditions for wall-function meshes will correspond to the wall function approach, but in the case of fine meshes the appropriate low-Reynolds number boundary 258 conditions will be applied. At the solid walls a no-slip boundary condition is imposed. An idealized physical model is required for the simplification of the analysis. Concurrently, decisions are made as to the extent of the finite flow domain in which the flow is to be simulated. Portions of the boundary of the flow domain coincide with the surfaces of the body geometry. Other surfaces are free boundaries over which flow enters or leaves. The geometry is modeled in such a manner as to provide input for the grid generation. Thus, the modeling often takes into account the structure and topology of the grid generation. Fig. 3(a-b) shows the grid systems in the computational domain for 3D and 2D cases. In this paper numerical results are generated using the 2D mesh for fast computation without sacrificing the accuracy much. Initial wall temperature (300 K), inlet total pressure (101325 Pa) and temperature (300 K) are specified. Ideal gas is selected as the working fluid. The turbulent intensity is selected as 5 % and inlet velocity is obtained as 150 m/s. The code has successfully validated with the help of benchmark solutions. In another attempt numerical studies for external flows have been carried out using two dimensional density based steady one-equation Spalart Allmaras model for the geometrical optimizing of a supercritical aerofoil, transformed from the rectangular nozzle, aiming for reducing the drag at wide range of operating conditions. The Sutherland law for viscosity is well suited for high-speed compressible flow. Though Cp and thermal conductivity are temperature dependent, for simplicity, initially we assumed it as constants at high speed flows [22]. V. RESULTS AND DISCUSSION The numerical results presented in this session are a pointer towards for the design optimization of a supersonic aircraft with rectangular CD nozzle for short takeoff. Fig. 4 shows the variations of pressure and velocity inside the CD nozzle. It is evident from these figures that the CD nozzle design is acceptable owing to the fact that shock waves are not encountered in the divergent session of the nozzle. rd International Conference on Trends in Mechanical and Industrial Engineering (ICTMIE2013) January 8-9, 2013 Kuala Lumpur (Malaysia) (a) Static Pressure (b) Velocity Magnitude Fig. 7 Comparison of the takeoff distance of a typical supersonic aircraft with and without CD nozzle. Fig. 4 Demonstrating the pressure and velocity variations inside the CD nozzle. Fig. 5 Demonstrating the wall pressure coefficient variatio ns in the CD nozzle. with and without CD nozzle under ideal conditions. We observed through the parametric analytical studies that the average outlet velocity is approximately 5 to 6 times the inlet velocity. During the external flow simulation we have observed that when the free stream Mach number exceeds the critical Mach number a pocket of supersonic flow occurs over the top surface as usual; but because of the top surface is relatively flat, the local supersonic Mach number is a lower value than would exist in the case of a conventional aerofoil. As a result, the shock wave that terminates the pocket of supersonic flow is weaker. In turn, the supercritical airfoil can penetrate closer to Mach 1 before drag divergence occurs. Admittedly, considerable amount of drag has been encountered during the transonic regime. Therefore one should propose more meaningful design for the drag reduction while proposing for the integrated approach for the design optimization of a supersonic aircraft for the smooth and short takeoff, which is beyond the scope of this paper. Fig. 8 shows the grid system in the computational domain of the supercritical airfoil. Fig. 9 shows the contours of the static pressure and the velocity magnitude over the supercritical airfoil. We observed that with the same inflow conditions the proposed supercritical airfoil could reduce the drag coefficient by 5 % than the conventional geometry. This supercritical airfoil can be further optimized for reducing the drag without affecting the structural and aerodynamics design requirements. The basic design approach behind supercritical shapes is to flatten the upper surface of the airfoil to reduce flow acceleration and to use a highly cambered aft section to generate the majority of the lift. The disadvantage of this approach is that aft-loaded wings shift the center of lift back, Fig. 6 Demonstrating the velocity variations in the CD nozzle. Fig. 5 shows the wall pressure coefficient variations and Fig. shows the velocity variations inside the CD nozzle. Based on the numerical data an analytical exercise has been carried out to estimate the take of velocity of a typical aircraft with T/W = 0. 85, Max. take-off weight = 46200 Kg, Thrust = 152 KN, C d = 0. 153, Wing span = 13. 46 m). We observed that with the rectangular CD nozzle with inlet velocity 150 m/s one can accelerate the aircraft for a short takeoff with 50 % reducti on in the takeoff distance. Fig. 7 shows the comparison of the takeoff distance of an aircraft 259 Fig. Grid system in the computational domain of the supercritical airfoil. 3rd International Conference on Trends in Mechanical and Industrial Engineering (ICTMIE2013) January 8-9, 2013 Kuala Lumpur (Malaysia) [3] L. E. Putnam, and J. Hodges, â€Å"Assessment of NASA and RAE Vicous [4] [5] [6] [7] Fig. 9 Pressure and velocity contours over the supercritical airfoil. [8] which necessitates moving the wings forward. This design tradeoff results in larger pitching moments, the need for larger and heavier control surfaces, and the need for stronger and heavier wing structures. VI. CONCLUDING REMARKS Successful numerical studies have been carried out for the conceptual design and optimization of short takeoff supersonic aircraft with cold flow nozzles. As a first step supersonic rectangular CD nozzle with multi-purpose frame is designed in such a way that during the early taxiing time the internal flow choking will be established without forming any shockwave in the divergent region for facilitating the aircraft for a smooth and short takeoff. Immediately after the takeoff the nozzle frame will be converted into rectangular supercritical wing for meeting the high speed aerodynamic design objectives. Parametric analytical studies have been carried out for both internal and external flows using suitable turbulence models. As speed increases, the compressibility (or ability to be squeezed into a smaller volume) of air increases. It implies that the density of air increases at high speeds resulting in greater drag on an airfoil. A supercritical airfoil is designed to delay the speed at which the compressibility effect becomes significant so that drag will be reduced. Note that any attempt for retaining the rectangular CD nozzle after the takeoff will be counter productive to the flight performance owing to the fact that its frame induces additional drag and the supersonic inflow will be shocked down by the CD nozzle at its throat leading to the formation of subsonic flow at its exit. Therefore design optimization of a short takeoff supersonic aircraft with cold flow nozzles is a daunting task and however must be attempted with caution. We concluded that the fluid-structural interactive code can possibly optimize the proposed conceptual design of a supersonic aircraft with flexible rectangular CD nozzle frames for the lucrative commercial applications. REFERENCES [1] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] Inviscid Interaction Methods for Predicting Transonic Flow over Nozzle Afterbodies, AIAA Paper No. 83-1789, July 1983. R. Wilmoth, Aerodynamics Interactions with Turbulent Jet Exhaust Plumes, JANNAF 13th Plume Technology Meeting, April 1982, Houston, Texas. E. Venkatapathy, and W. J. Feiereisen, 3-D Plume Flow Computations with an Upwind Solver,† AIAA Paper No. 88-3158, AIAA/ASME/SAE/ASEE 24th Joint Propulsion Conference, July 1988, Boston, MA, USA. G. A. Hasen, Navier-Stokes Solutions for an Axisymmetric Nozzle,I1 AIAA Journal, Vol. 20, Sept. 1982, pp. 1219-1227. S. Dash, and P. Del Guidice, â€Å"Shock Capturing Finite-Difference and Characteristic Reference Plane Techiques for the Prediction of Threedimensional Nozzle- Exhaust, NASA CR 145366, May 1978. P. D. Thomas, â€Å"Numerical Method for Predicting Flow Characteristiccs and Performance of Nonaxisymmetric Nozzles, Part 2 Application, NASA CR 3264, Oct. 1980. K. M. Peery, â€Å"Non-Axisymmetric Nozzle/Aftbody Flow Field Analysis,† AFWALTR- 81-3046, June 1981. D. E. Wolf, R. A. Lee, and S. M. Dash, â€Å"Parabolized Navier-Stokes Analysis of Scramjet Hypersonic Nozzle Flowfields,ll AIAA Paper No. 87-1897, AIAA/SAE/ASME/ASEE 23rd Joint Propulsion Conference, June 1987, San Diego, CA. C. F. Shieh, â€Å"Navier-Stokes Solutions of Transonic Nozzle Flow with Shock-Induced Flow Separationsr1I AIAA Paper No. 8-3614, AIAA/ASME/SIAM/APS 1st National Fluid Dynamics Congress, July 1988, Cincinnati, OH, USA. R. M. Beam, and R. F. Warming, An Implicit Factored Scheme for the Compressible Navier-Stokes Equations,† AIAA Journal, Vo1. 16, April 1978, pp. 393-402. G. K. Cooper, The PARC Code: Theory and Usage, AEDC-TR-87-24, Oct. 1987. T. H. Pulliam, Euler and Thin Layer Navier-Stokes Codes: ARC2D, ARC3D, Notes for Computational Fluid Dynamics Users Workshop,† The University of Tennessee Space Institute, Tullahoma, Tn. , UTSI Pub. E02-4005-023-84, 1984, pp. 15. 1-15. 85. A. T. Hsu, and M. S. Liou, A Computational Analysis of UnderExpanded Jets in the Hypersonic regime, NASA TM 101319, 1988. G. J. Harloff, H. T. Lai, and E. S. Nelson, â€Å"Two-Dimensional Viscous Flow Computations of Hypersonic Scramjet Nozzle Flow fields at Design and Off Design Conditions, NASA TM 182150, June 1988. K. B. M. Q. Zaman, Flow-Field Surveys For Rectangular Nozzles, Glenn Research Center, Cleveland, Ohio, NASA/TM—2012-217410, AIAA– 2012–0069. Ganesh Raman, Michael Hailyef and Edward J. Rice, â€Å"Flip-Flop Jet Nozzle Extended to Supersonic Flows,† AIAA Journal, Vol. 31, No. 6, June 1993, pp. 1028-1035. M. Lozanova, P. Stankov, â€Å"Experimental investigation on the similarity of a 3D rectangular turbulent jet,† Experiments in Fluids 24 (1998) 470478, Springer-Verlag 1998. A. Mohamed, A. Hamed, and T. Lehnig, â€Å"Supersonic Rectangular OverExpanded Jets of Single and Two-Phase Flows, ISABE 2003-1119. Mohammed Hamed Alnahhal, â€Å"Turbulent Rectangular Jets,† Ph. D Dissertation, Department of Mechanical Engineering and Aeronautics, University of Patras, Rio 26 504, Greece, 2010. Shantanu Khanna, â€Å"CFD Analysis of Super Critical Aerofoil over simple Aerofoil†, M. S Thesis, College of Engineering, University of Petroleum and Energy Studies, May 2011. 2] H. Lai and E. Nelson, â€Å"Comparison of 3D Computation and Experiment for Non-Axisymmetric Nozzles†, NASA Contractor Report 182245, NASA Lewis Research Center Group, Cleveland, Ohio, February 1989, AIAA-89-0007. Re, R. J. , and Leavitt, D. L. , Static Internal Performance of SingleExpansion-Ramp Nozzles with Vario us Combinations Of Internal Geometric Parameters, NASA TM and 86270, 1984. 260 3rd International Conference on Trends in Mechanical and Industrial Engineering (ICTMIE2013) January 8-9, 2013 Kuala Lumpur (Malaysia) Spare Parts Inventory Model for Auto Mobile Sector Using Genetic Algorithm S. Godwin Barnabas, I. Ambrose Edward, and S. Thandeeswaran Abstract—In this paper the objective is to determine the optimal allocation of spares for replacement of defective parts onboard of a usage. The optimal inventory control methodologies intend to reduce the supply chain cost by controlling the inventory in an effective manner, such that, the SC members will not be affected by surplus as well as shortage of inventory. In this paper, we propose an efficient approach that effectively utilizes the Genetic Algorithm for optimal inventory control. This paper reports a method based on genetic algorithm to optimize inventory in supply chain management. We focus specifically on determining the most probable excess stock level and shortage level required for inventory optimization in the supply chain so that the total supply chain cost is minimized . So, the overall aim of this paper is to find out the healthy stock level by means of that safety stock is maintained throughout the service period. Keywords—Excess Stock, Genetic algorithm, Inventory, Optimization, Safety stock. service sector. Inventory is held throughout the supply chain in the form of raw materials, work in progress, and finished goods. II. LITERATURE REVIEW Supply chain network is a complex network, which consists of multiple manufacturers, multiple suppliers, multiple retailers and multiple customers. The accomplishment of beam-ACO in supply-chain management has been proposed by Caldeira et al. [12]. Beam- ACO has been used to optimize the supplying and logistic agents of a supply chain. A standard ACO algorithm has aided in the optimization of the distributed system. The application of Beam-ACO has enhanced the local and global results of the supply chain. A beneficial industry case applying Genetic Algorithms (GA) has been proposed by Wang et al. [13]. The case has made use of GAs for the optimization of the total cost of a multiple sourcing supply chain system. The system has been exemplified by a multiple sourcing model with stochastic demand. A mathematical model has been implemented to portray the stochastic inventory with the many to many demand and transportation parameters as well as price uncertainty factors. A genetic algorithm which has been approved by Lo [14] deals with the production inventory problem with backlog in the real situations, with time-varied demand and imperfect production due to the defects in production disruption with exponential distribution. Besides optimizing the number of production cycles to generate a (R, Q) inventory policy, an aggregative production plan can also be produced to minimize the total inventory cost on the basis of reproduction interval searching in a given time horizon. P. Radhakrishnanet. al. [18] developed P. Radhakrishnan et. al. [18] developed a new and efficient approach that works on Genetic Algorithms in order to distinctively determine the most probable excess stock level and shortage level required for Inventory optimization in the supply chain such that the total supply chain cost is minimized. Many well-known algorithmic advances in optimization have been made, but it turns out that most have not had the expected impact on the decisions for designing and optimizing supply chain related problems. Some optimization techniques are of little use 261 I. INTRODUCTION HE design and operation of spare part management systems is very important for automobile sector, Prior relevant system could be grouped in two categories. It is aimed to find optimal demand for a given spare parts management system; that is, how to determine optimal inventory level in order to reduce cost. This paper attempts to solve a comprehensive design problem for a spare part management system. Every automobile sector should proceed systematically and establish an effective Spare parts management system. Inventory encompasses all raw materials, work in process, and finished goods within the supply chain. Changing Inventory policies can dramatically alter the supply chain’s efficiency and responsiveness. Inventory is an important cross functional driver of supply chain performance. An important role that can be satisfied by having the product ready and available when the customer wants it to reduce the customer waiting time in the S. Godwin Barnabas 1. is an Assistant Professor, Mechanical Department in the Velammal College of Engineering and Technology,Madurai,Tamilnadu,India (Phone: +919943338837 ; e-mail: [emailprotected] com ). I. Ambrose Edward 2. is an Assistant Professor, Mechanical Department in the Velammal College of Engineering and Technology,Madurai,Tamilnadu,India (phone:+919952199565; e-mail:[emailprotected] com) S. Thandeeswaran 3. is an Assistant Professor, Mechanical Department in the Velammal College of Engineering and Technology,Madurai,Tamilnadu,India (Phone:+919790362087; e-mail: thandeeswaran. [emailprotected] com). T

What Everybody Is Saying About Chicago Style Essay Samples Is Wrong and Why

What Everybody Is Saying About Chicago Style Essay Samples Is Wrong and Why Simple writing isn't like a part of furniture. Just enable the ideas come out. Also, make sure the tone which you use in writing the article doesn't ensure it is vulgar or offensive in any fashion. Your style needs to be vivid and to present decent conversation. There are many categories of topics for you to select from. Because you're going to make them an irresistible offer for a completely free gift on a topic which they are interested in. When you're choosing an essay topic, it is necessary to pick one which has a lot of information and statistics to back up your standpoint, and don't exaggerate any info that you've chosen to write about. You might even wish to consider employing a controversial topic like religion as it can be looked at from several diverse perspectives. 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The Best Way to Find a Good College Essay Topic

The Best Way to Find a Good College Essay TopicIf you want to know how to find a good college essay topic then the best way is to take a question and answer quiz on writing college essays. This can be used to help you find a topic that interests you are able to talk about. There are many different websites that will allow you to get a question and answer quiz for free and these should be researched for topics you are interested in writing.Writing an essay can be a very big undertaking and as such you need to know where to start when you are tackling this task. The easiest way to do this is to use a question and answer quiz. They will help you choose a topic that you will enjoy and they will help you write an essay on the topic.It can be daunting and quite frustrating to pick a topic for an essay especially if you have not written an essay before. It can be very difficult to get a topic because it is very competitive and many other students are looking for the same topic too. Once you get a topic it is important to go back and read through it a few times until you understand what it is that you are doing. The first time you write it down is the worst time to do so as you might forget something.The last thing you need to do is go through your essay several times and take out all the unnecessary stuff. The points you should be writing down are grammatical mistakes, essay structure and the main idea of the essay. You need to write them down as soon as you can because they make up the bulk of your writing.Taking a quiz will help you to work out what the most important things are in writing an essay. You will know the main points and you will also know the most important things in your essay that you need to focus on. There are lots of great websites online that will offer you a question and answer quiz that will give you a good idea about how to write an essay.Most of the people who take an essay test like to sit down with a pad and pen and write the whole essay out on paper. This is not recommended as it takes ages and is quite a chore to do. The key to writing a good essay is to do it quickly and you do not want to spend a lot of time on this.A good way to find an essay topic is to take a question and answer quiz on writing college essays. You can find some that are free and others that you will have to pay for. The free ones will give you an idea on the topics which are very common. It will help you pick the topic that you will enjoy.A question and answer quiz will allow you to try and learn something from reading the answers and having a few drinks will help you concentrate on getting the most from the free online question and answer quiz. Once you finish the quiz, you will be more focused and able to write a better essay. So make sure you take the time to study for it will be worth it.

What Does Your Course of Study Have to Do With Your CSC Essay Writing?

What Does Your Course of Study Have to Do With Your CSC Essay Writing?Students who are interested in achieving good grades can participate in the CSC essay writing topics. These topics are among the best and most interesting assignments that students can take part in. There are some reasons why this is so. The coursework requires preparation for a specific purpose, that is how to prepare for the essay writing topics.You will find that the whole course of study is related to writing. The course of study has an important role to play in preparing you for the essay writing. It is also a prerequisite for you to fulfill. The whole course of study, along with the essay writing topics, is all about writing.The entire course is about creating a whole word list. This is used in the purpose of composing sentences and paragraphs that will make up your thesis statement. This is something that you will have to work out all by yourself. This will give you practice in constructing your thesis state ment.What this means is that this is a very important course of study that you will be participating in. It will be used to assist you in writing an essay that you can submit for your CSC. In addition, the course of study is done in order to help you write the thesis statement. This is used as a background to the next step of the writing process.Students who are taking this course of study are also making it a point to examine what they are writing in order to see how good they really are. The same thing applies to the essay writing as well. You will not do it for the sake of having to write your thesis statement. You will do it because this is something that is very important.The whole course of study will be focusing on facts and figures. This is going to make sure that you have to work with things that you know how to work with. That is why the thesis statement will take the bulk of the time. It will be done at the end of the class. You will have to be very careful when you are d oing it.There is one thing that you should be aware of. Your course is not necessarily going to be based on this particular thesis statement. This is used as a step in the way that you will write your own thesis statement. This is something that will prepare you for the future. In the process of doing your CSC essay writing, you will be ready for more difficult assignments.

Sample Essay Literary Analysis for the Story of an Hour

Sample Essay Literary Analysis for the Story of an HourSample Essay Literary Analysis for the Story of an Hour by Margot Bourgeois is a short, yet powerful, novel that explores the lessons of motherhood and the dangers inherent in being a single mother in a very unique, contemporary setting. Although the story is brief, it packs a wallop. One major element of the story is a novel that concerns how fathers view their daughters and how they view themselves.The novel follows four generations of a family with four daughters, one son, and a father who only see his children as 'toes.' This focus on the father figures does not give a lot of space to the father's own personality and his relationship with his daughters. One thing about the novel is that the stories are told in the third person. In this manner, one can get a good idea of the feelings and thoughts of the daughters, their thoughts of the father, and how they are trying to live up to the expectations set forth by their fathers.Th e mother, Diana is the center of the story and this is where the essay will focus on. She is raised in a world where she is told that she is a bad mother and her lack of understanding of how a child's brain works leads her to thinking she is incapable of raising her own children. Diana feels she is being punished by God for being too foolish in her choice in a mate.Throughout the story, we follow her from childhood through her formative years as a good mother to her old age when she becomes disillusioned. Diana is an unlikable character in the story, but she is written so well that the reader will come to love her despite her faults. For readers looking for an interesting and uplifting novel, Sample Essay Literary Analysis for the Story of an Hour should be on their short list. Although the story is brief, it packs a wallop.What will the essay cover? I will focus on three things: the teacher's role in the narrative, the expectations of the daughter to be perfect in every way, and th e lesson that the daughter learns from the story of the hour, that women are to be treated like wives and mothers.One thing to note about the essay is that I did not include much in the way of historical context. This is one of the advantages of doing the essay in a journal format. The author can write about her subject and make any necessary changes to the way she says things in the book if necessary. There is also nothing to argue over.The essay is a little longer than the length of the novel. It is a good idea to begin with the end in mind and then work your way back to the beginning of the book as you continue. I hope this essay has been helpful and if you have any comments or questions, please leave them in the comments section below.

House Fly Essays - Muscidae, Housefly, Fly, Insect, Maggot

House Fly The House Fly The housefly is a very widely known insect. To most people it is just a pest. To many insects, it is a source of food. In many ways the housefly is a pest, but in many others ways it is beneficial. The fly has a head, thorax, and abdomen. It is furry with big compound eyes. Its 2 wings are so thin you can see the veins in them. It has a sucking mouth part. It is black with gray stripes, and on the side are air holes called spiracles. These are used for breathing. The fly is located everywhere except for extreme temperature places. It will eat any food or garbage. It even eats poo. They carry diseases such as malaria. It lays them when it lands on something. There are 4 stages of life. First the adult female will lay up to 250 eggs at once in the water or on the ground. Then the larva, called maggots, hatches from the egg. They just eat so they can grow. Then come the pupa. It goes inside a cocoon for 3-6 days. It gradually looses it's outer skin. Then when it is done it becomes an adult fly. It will live for about 3-4 weeks during the summer. Now it will find a mate and reproduce sexually. Then the cycle will begin again. I think that the fly is very important for the other insects that eat it and survive off of it. But I also think, like most people, that the fly is one of the most annoying insects ever. Science