格子乱流中におけるNACA0012翼の空力特性

抄録

In order to investigate effects of free stream turbulence on the aerodynamic performance of the NACA0012 at the Reynolds number 1.48×10⁵, a numerical analysis was performed with a turbulence grids installed upstream of the airfoil. Since the simulation domain has sufficient resolution to reproduce the grid turbulence upstream of the airfoil, it is possible to realize a homogenous isotropic turbulence flow such as the atmospheric turbulence or wake flow of turbines. The generated turbulent flow field showed the same characteristics of turbulence attenuation as the previous study, and the inertia sub-ranges were observed in the velocity fluctuation spectra. In the case of an uniform flow without inflow turbulence, the separation bubbles are formed on the blade suction surface, and there make a step in the pressure distribution near the leading edge. On the other hand, in the case of inflow turbulence exist, the separation bubbles disappeared and the flow around the suction surface is distributed along the airfoil. In this Reynolds number and the angle of attack is 6 °, inflow turbulence increases the lift coefficient and decrees the drag coefficient.