Date of Award
Master of Science (MS)
The goal of this research is to perform 2D turbulent flow simulations to predict the flow past a triangular airfoil used for a Mars air vehicle and in a sweeping jet actuator used for active flow control. Simulations are performed using the commercial CFD software ANSYS Fluent.
The thesis consists of two parts. The first part of the thesis deals with the CFD simulations of a triangular airfoil in low-Reynolds-number compressible flow. This airfoil is one of the candidates for propeller blades on a possible future Martian air vehicle design. The aerodynamics and flow physics of the triangular airfoil is studied at angles of attack (AOA) from deg. to deg. at Mach number of 0.5. Compressible Reynold-Averaged Navier-Stokes (RANS) equations with a number of turbulence models, namely the SA, SST k-ω, and recently developed Wray – Agarwal (WA) model are solved. The computations are compared with the experimental data to assess the accuracy of various turbulence models. Lift coefficient, drag coefficient and pressure coefficient are obtained by performing computations at different angles of attack at a constant Mach number. It is shown that SST k-ω and WA model give the most accurate result.
The second part deals with the simulation of the unsteady oscillatory flow field of a Sweeping Jet Actuator (SWJ) used in active flow control of flow past wings. Based on recent experiments, sweeping jet actuators have been found to be more efficient for controlling flow separation in terms of mass flow requirements compared to constant blowing and suction or even synthetic jet actuators. They produce span-wise oscillating jets and therefore are called the sweeping jets. The frequency and span-wise sweeping extent depend on the geometric parameters and mass flow rate entering the actuators through the inlet section. The flow physics associated with these actuators is quite complex and is not fully understood at this time. The unsteady flow generated by such an actuator is simulated using the CFD solver ANSYS Fluent. k-ε model was used to get the computational results. Computed mean and standard deviation of velocity profiles generated by the actuator in quiescent air are compared with experimental data. Simulated results show good agreement with the experimentally observed trends with parametric variation of geometry and inflow conditions.
Ling Zhou Swami Karunamoorthy