International Journal for Research in Applied Science & Engineering Technology (IJRASET) ISSN: 2321-9653; IC Value: 45.98; SJ Impact Factor: 7.177 Volume 7 Issue XI, Nov 2019- Available at www.ijraset.com © IJRASET: All Rights are Reserved 727 Numerical Investigation on Stress and CFD Analysis of Aircraft Wings for Better Performance Rajesh Kumar 1 , Ch. Shalini 2 1, 2 CVR college of Engineering, Hyderabad Abstract: The air foil section is the incarnation of a wing or a lifting surface which is very important in an airplane wing design. While the shape of the air foil changes, their aerodynamic characteristics also change. This investigation deals with a standard symmetrical air foil as reference and the effect of changes in shape due to minor variations in the coordinates. Three new air foil shapes have been produced in this optimisation process. The aerodynamic characteristic results such as the coefficients of lift and drag (Cd, Cl), pressure coefficient (Cp), moment coefficient (Cm) are noted for all three different profiles, produced from the standard NACA 0012.Wortmann fx 63-137 and Clark y air foils are also included in our project. The modus-operandi used in this optimisation process is the Computational Fluid Dynamics (CFD). We have used ANSYS FLUENT and MODAL for flow and stress analysis. Flow changes have been recorded for these air foil shapes and the results are arrived for finding the best air foil that can be advisable. Keywords: Airfoil, airfoil shape, aerodynamic characteristics, Fluent, Modal. I. INTRODUCTION The wing may be considered as the most important component of an aircraft, since a fixed-wing aircraft is not able to fly without it. It is made up of an airfoil which have some cross sectional area. Since the wing geometry and its features are influencing all other aircraft components, we begin the detail design process by wing design. The primary function of the wing is to generate sufficient lift force or simply lift (L). However, the wing has two other productions, namely drag force or drag (D) and nose-down pitching moment (M). While a wing designer is looking to maximize the lift, the other two (drag and pitching moment) must be minimized. In fact, wing is assumed ad a lifting surface that lift is produced due to the pressure difference between lower and upper surfaces. A wing following the laminar stream has much larger thickness in the middle of the camber line. It represent negative weight slant along the stream. So if we maintain the camber I the center, then a laminar stream with high rate high rate at high speed can be achieved. II. WING DESIGN The wing may be considered as the most important component of an aircraft, since a fixed-wing aircraft is not able to fly without it. Since the wing geometry and its features are influencing all other aircraft components, we begin the detail design process by wing design. The primary function of the wing is to generate sufficient lift force or simply lift (L). However, the wing has two other productions, namely drag force or drag (D) and nose-down pitching moment (M). While a wing designer is looking to maximize the lift, the other two (drag and pitching moment) must be minimized. In fact, wing is assumed ad a lifting surface that lift is produced due to the pressure difference between lower and upper surfaces. Aerodynamics textbooks may be studied to refresh your memory about mathematical techniques to calculate the pressure distribution over the wing and how to determine the flow variables. Basically, the principles and methodologies of “systems engineering” are followed in the wing design process. Limiting factors in the wing design approach, originate from design requirements such as performance requirements, stability and control requirements, producibility requirements, operational requirements, cost, and flight safety. Major performance requirements include stall speed, maximum speed, take off run, range and endurance. Primary stability and control requirements include lateral-directional static stability, lateral-directional dynamic stability, and aircraft controllability during probable wing stall. One of the necessary tools in the wing design process is an aerodynamic technique to calculate wing lift, wing drag, and wing pitching moment. With the progress of the science of aerodynamics, there are variety of techniques and tools to accomplish this time consuming job. Variety of tools and software based on aerodynamics and numerical methods have been developed in the past decades. The CFD Software based on the solution of Navier-Stokes equations, vortex lattice method, thin air foil theory, and circulation are available in the market. The application of such software –that are expensive and time-consuming – at this early stage of wing design seems un-necessary. Instead, a simple approach, namely Lifting Line Theory is introduced. Using this theory, one can determine those three wing productions (L, D, and M) with an acceptable accuracy.