CFD simulation of transonic turbulent flow past NACA 0012 aerofoil

Abstract

An aircraft needs to operate under different free stream conditions during different phases of its flight like, take-off, climb, cruise, descend and finally landing. In the transonic speed regime at which most of the commercial aircrafts operate, the aerodynamic performance of the aircraft is affected to a great extent by the presence of various nonlinearities. The present work focuses on the analysis of transonic flow past a NACA 0012 Aerofoil, which is widely used for modern commercial passenger aircrafts operating at transonic flight speed. The compressible flow field around a NACA0012 aerofoil which forms the cross section of an aircraft wing has been computed using the ANSYS Fluent 14.5. The simulation 2D compressible flow of air around NACA 0012 aerofoil for a range of flow Mach numbers and Angles of Attack, forms the major contents of this work. Navier Stokes equations for conservation of mean momentum components, coupled to the continuity equation and additional equations for relevant turbulence scalar conservation have been simultaneously solved for a given grid network around the aerofoil. Two different turbulence models viz., Spalart-Allmaras and k-co turbulence models have been used for the computations. The effect of Mach number and Angle of Attack on the aerodynamic performance of the NACA0012 aerofoil has been studied for a given flow Reynolds number. The detailed chord wise distribution of static pressure, skin friction coefficient and turbulence intensity has been compared to reliable wind tunnel measurement data available in open literature. The computed surface pressure and wall shear stress on the aerofoil have been properly integrated to derive the overall aerodynamic performances like variation of Lift and Drag Coefficient and the Pitching Moment of the aerofoil for given angles of attack and flow Mach numbers.