翼栅绕流流场数值模拟及动力性能研究

基于2D不可压缩定常流动的控制方程,对5个NACA4412非对称翼型组成的平面直列翼栅绕流流场进行了数值模拟,对比分析了同一翼型在翼栅中工作和单独绕流时的升、阻力情况,验证了翼栅装置工作的可行性,反映了翼栅绕流的客观规律性。结果表明:翼栅翼型头部流速和压力急剧变化,尾部出现流涡尾迹,前部是负压区,后部是正压区,内部流速大,压力小;在1/3弦长附近翼栅翼型表面压力出现拐点,拐点之前翼型上下表面压力差较大,拐点之后翼型上下表面压力差较小;翼栅内部流场具有相似、相近性,外部流场差异性较大;翼型的压力差是产生升力的主要原因。

The Numerical Simulation and Dynamic Performance of Flow Fields Around the Wing Cascade

The control formula of steady flow based on 2-dimensional incompressibility is used to numerically simulate the flow fields around planar in-line wing cascade,which is composed of 5 sheets of asymmetric NACA4412 aerofoils,to analyze and compare the lift or drag coefficients of the same aerofoil when it is within the wing cascades and works alone respectively,and to validate the feasibility of the wing cascade device putting into service and the principium of flow around wing cascade.The results show that water velocity and pressure vary rapidly on the head,and the flow eddy occurs on the tail;negative pressure is in the front,while positive pressure is in the heel,and water velocity is large inside.The pressure on the aerofoil has a deflection point on one third of chord length,and differential pressure before chord length is larger while that behind is smaller.The interior flow fields in the wing cascade are similar to each other,while the exterior ones are greatly different,and the differential pressure produces lift primarily.