Direct numerical simulation of NACA0012 cascade flow at low Reynolds number

Low Reynolds number flow field developed around a cascade of NACA0012 was numerically simulated by directly solving the unsteady two-dimensional Navier-Stokes equations through weighted essentially non-oscillatory(WENO) schemes with 7th order accuracy.As compared with references,direct numerical simulation results indicate that vortex-shedding process at the cascade trailing edge is similar to that of flow over a cylinder and the statistical traits of the wake region are similar between cascade flow and single airfoil flow at low Reynolds number,but the former is stronger.The vortex-shedding has a significant impact on the overall flowfield,which forms unsteady separation on the airfoil and makes the total pressure in the wake region vary instantaneously.With the decrease of the pitch,the average separation position moves towards the leading edge;the frequency and amplitude of total pressure in the wake region increase markedly,and the statistics of pulse velocity becomes bigger.