Numerical Investigation to Predict the Effect of Plasma Actuator on Flow Control to Enhance Aerodynamic Characteristics and Acoustics of Symmetric Airfoil—A RANS Approach

Abstract

AbstractFlow control methodologies are an important area of study for the last few decades in the history of modern aerodynamics. Control of flow means a slight shift in flow structure by means of active or passive methods that serve a preferably significant aerodynamic advantage. The aim of this study is to predict flow behavior over an airfoil under the effect of a plasma actuator; an extensive numerical investigation on a symmetric airfoil with a plasma actuator’s effect over it has been conducted using Ansys Fluent tool. Experimental data from NASA turbulent flow for NACA0012 is used as a benchmark and validated using the Spalart–Allmaras RANS model. User Defined Functions (UDF) with plasma source term are defined in C language which numerically simulates the Lorentz force over the airfoil which in turn is due to the effect of plasma actuators. Aerodynamic coefficients like Drag, Lift coefficients, and flow field are compared and the effect on the Lift/Drag ratio is evaluated in the presence of the plasma actuator’s effect. This is indicated by the change in drag coefficient which is reduced by 13% and the lift coefficient increased by 1.2%. To evaluate the acoustics of the airfoil, Ffowcs Williams–Hawkings (Fw-H) integral method is used, Sound Pressure Level (SPL) is compared in Fast Fourier Transforms (FFT) with frequency domain, and the SPL is used to compare the effect of plasma actuator on acoustics. The average reduction in SPL is around 3% due to plasma actuators for Angle of Attack of 5°–15°, Maximum reduction of 5% for the angle of attack of 15° for plasma actuators located at 0.2 of the chord.KeywordsSymmetric airfoilFlow controlTurbulent flowPlasma actuatorUser defined functionsLorentz forceAcousticsSound pressure level