Adaptive airfoils and wings can provide superior performance at the expense of increased cost and complexity. In this paper, an aerodynamic optimization algorithm is used to assess an adaptive airfoil concept for drag reduction at transonic speeds. The objective is to quantify both the improvements in drag that can be achieved and the magnitude of the shape changes needed. In an initial study, ...

We perform large-eddy simulation of turbulent flow separation over an airfoil and evaluate the effectiveness of synthetic jets as a separation control technique. The flow configuration consists of flow over an NACA 0015 airfoil at Reynolds number of 896,000 based on the airfoil chord length and freestream velocity. A small slot across the entire span connected to a cavity inside the airfoil is ...

ABSTRACT: Inspired by humpback whale’s flippers [1, 2], this study investigated the effect of aspect ratio and shape of protuberances on the performance of airfoil with protuberances on leading edge. NACA0012 foil is used for modifying the leading edge with three different forms and three aspect ratios (1, 2, 3). The experiment of the airfoils was carried out in a low-speed wind tunnel, includi...

For aerodynamic modeling and optimization, it is desirable to limit the number of design variables to reduce model complexity and the requirements of the applied optimization scheme. The Class/Shape Transformation (CST) surface parameterization method presented by Kulfan has proven to be particularly useful for this while maintaining a wide range of applications. These include everything from s...

Multiple numerical solutions of inviscid transonic flow over several airfoils exist at certain Mach number and angle of attack. Global linear stability analysis of the multiple solutions is conducted in this paper. Linear perturbation equations of the Euler equations around a steady-state solution are formed, an eigenvalue problem is then constructed using the modal analysis approach, then it i...

This paper deals with the numerical simulation of the twodimensional, incompressible, steady air flow past an airfoil for a solar powered unmanned aerial vehicle (UAV) with internal propulsion system. This airfoil results from a NACA 2415 four digits family base airfoil modification [7] and has a propulsive outlet with the shape of a step on the suction surface. The analysis involved the airfoi...

An efficient method for scattering Genetic Algorithm (GA) individuals in the design space is proposed to accelerate airfoil shape optimization. The method used here is based on the variation of the mutation rate for each gene of the chromosomes by taking feedback from the current population. An adaptive method for airfoil shape parameterization is also applied and its impact on the optimum desi...

The present study is devoted to an approximate modeling for numerical simulation of flows past oscillating airfoils. In this study, it is shown that the harmonic oscillating objects can be studied by simple numerical codes that are not able to solve moving grids. Instead of using moving grid for the simulation of flowfield around an oscillating airfoil, this unsteady flow is solved on a fixed g...

This project analyzes 2-D, inviscid, steady supersonic flow over different airfoil designs at Mach 2.2 while at 60,000ft. The airfoils tested have sharp leading and trailing edges. The shapes range from diamond to convex to a combination of the two. A hybridization of Computational Fluid Dynamics (CFD) and Computational Acoustic simulations are used to obtain values for the lift coefficient, dr...

Study of permeability of Fibrous Composites is important in several natural and industrial processes in mechanical engineering. In this study, a comprehensive mathematical model is presented for calculation of normal permeability of ordered elliptical fibrous media. An innovative scale-analysis technique is employed for determining the normal permeability of elliptical fibrous media. In this te...