Computational study into the flow field developed around a cascade of NACA 0012 airfoils

Abstract

Numerical simulation of flow past airfoils is important in the aerodynamic design of aircraft wings and turbomachinery components. These lifting devices often attain optimum performance at the condition of onset of separation. Therefore, separation phenomena must be included if the analysis is aimed at practical applications. Consequently, in the present study, numerical simulation of steady flow in a linear cascade of NACA 0012 airfoils is accomplished with control volume approach. The flow field is determined by solving two-dimensional incompressible Navier-Stokes equations while the effects of turbulence are accounted for by the k- ϵ model. Boundary layer developed at the suction and the pressure surfaces of the airfoil is investigated together with relevant pressure contours for different angles of attack and solidity. Separation point at the airfoil surface is predicted at high angles of attack. Pressure, lift and drag coefficients are computed and the results are compared with the predictions of isolated single NACA 0012 airfoil as well as the data available in the literature. However, the leading edge rotation is also introduced to determine the effect of leading edge rotation on stall inception of isolated airfoil. It is found that increase in solidity increases the angle of attack at which separation occurs and pressure, lift and drag coefficients are highly influenced by the angle of attack and the solidity. The results of leading edge rotation indicates that the drag coefficient reduces considerably while the lift coefficient increases.