循环控制无缝隙高升力系统的实验研究

When air is blown from a slot directly upstream of a flap, the flow over the flap can bear large adverse
pressure gradients without separation. This effect is used to design high-lift airfoils with low momentum
coefficients of blowing. For experimental assessment of these airfoils a rectangular wing with an aspect
ratio of 4.3 was built. The flow around the model in a low speed wind tunnel is analysed using pressure
measurements and long distance microscopic particle image velocimetry. To measure the velocity in the
vicinity of the slot and next to the surface of the flap the jet is seeded with particles. For Reynolds
numbers of about Re = 1 · 106 the dimensionless momentum coefficient of the jet and the angle of attack
of the airfoil are varied. Numerical simulations of the three-dimensional flow around the circulation
control airfoil in the wind tunnel are compared to the experimental data. Good agreement is observed
in terms of pressure distributions and velocity profiles. 显微粒子成像测速系统(Micro PIV)