This paper aims to deal with the numerical investigation of laminar separation bubble (LSB) characteristics (length and height of the bubble) of SS007 airfoil at the chord Reynolds number of Rec = 0.68 × 105 to 10.28 × 105.,The numerical simulations of the flow around SS007 airfoil were carried out by using the commercial fluid dynamics (CFD) software, ANalysis system (ANSYS) 15. To solve the governing equations of the flow, a cell-centred control volume space discretisation approach is used. Wind tunnel experiments were conducted at the chord-based Reynolds number of Rec = 1.6 × 105 to validate the aerodynamic characteristics over SS007 airfoil.,The numerical results revealed that the LSB characteristics of a SS007 airfoil, and the aerodynamic performances are validated with experimental results. The lift and drag coefficients for both numerical and experimental results show very good correlation at Reynolds number 1.6 × 105. The lift coefficient linearly increases with the increasing angle of attack (AOA) is relatively small. The corresponding drag coefficient was found to be very small. After the formation of LSB which leads to burst to cause airfoil stall, the lift coefficient decreases and increases the drag coefficient.,Low Reynolds number and LSB characteristics concept in aerodynamics is predominant for both civilian and military applications. These include high altitude devices, wind turbines, human powered vehicles, remotely piloted vehicles, sailplanes, unmanned aerial vehicle and micro aerial vehicle. In this paper, the micro aerial vehicle flight conditions considered and investigated the LSB characteristics for different Reynolds number. To have better aerodynamic performances, it is strongly recommended to micro aerial vehicle (MAV) design engineers that the MAV is to fly at 12 m/s (cruise speed).,MAVs and unmanned aerial vehicles seem to give some of the technical challenges of nature conservation monitoring and law enforcement a versatile, reliable and inexpensive solution.,The SS007 airfoil delays the flow separation and improves the aerodynamic efficiency by increasing the lift and decreasing the drag. The maximum increase in aerodynamic efficiency is 12.5% at stall angle of attack compared to the reference airfoil at Re = 2 × 105. The results are encouraging and this airfoil could have better aerodynamic performance for the development of MAV.

Numerical and experimental study of the laminar separation bubble over SS007 airfoil for micro aerial vehicles

Numerical Investigation for Selection of Airfoil with Regard to Flying Wing Applications

This paper describes the aerodynamic simulation and optimization of NACA 0012 airfoil at a low Reynolds number using unsteady Reynolds-averaged Navier-Stokes (URANS) and Spalart–Allmaras turbulence model in Ansys Fluent. The purpose of this paper is to simulate and optimize the airfoil to get better aerodynamic performances at low Reynolds numbers. The Parsec method was selected for the optimization of the NACA 0012 airfoil. Both of these airfoils are simulated using CFD Fluent between 0 to 13-degree angle of attack at a low Reynolds number of 200000. To simulate the airfoil, mesh generation is crucial so an O-grid structured mesh is created. After the simulation, several aerodynamic performances are compared between the airfoils, such as lift coefficient, drag coefficient, pressure coefficient, and lift-to-drag ratio. And the calculated results from Xfoil are taken as references. Between NACA 0012 and optimized NACA 0012, the optimized airfoil showed better aerodynamic performances than the normal one, which was the goal of this paper. Later on, the different flow field variables, such as density, temperature, pressure, and vorticity magnitude were analyzed and compared. Both the airfoils at a different angle of attack were analyzed for these functions, like 7°, 11°, and 20° AOA. During the analytical process, Q-criterion appears to be a very important method of vortex identification in the flow field. With this analysis, we came to know, that as the angle of attack increases the adverse pressure gradient also increases, which creates a big reverse flow.

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A. Immanuel Selwyn Raj

Papers

Design of low Reynolds number airfoil for micro aerial vehicle