不同雷诺数下二维椭圆柱绕流的数值模拟研究

The computational fluid dynamics software Fluent was used to numerically study the flow around a two-dimensional elliptical cylinder under different Reynolds numbers(Re=100, 3900, 3.5×10⁶). The different axial length ratios (2b/2a=cosθ, θ=0°, 15°, 30°, 45°, 60°) characteristics of flow around an elliptical cylinder. Through comparison of the eddy current at the tail, the lift coefficient C_L, the drag coefficient C_D, and the Strouhal number St, it is found that due to the characteristics of the elliptical cross-section deflection line, the elliptic cylinder flows around with the increase of θ under three types of Reynolds numbers. The strength of the wake vortex is reduced, and the change of the flow field reduces the pressure coefficient of the cylindrical surface, which ultimately leads to a decrease in the average value of the cylindrical lift coefficient amplitude and the drag coefficient. The Strouhal number St changes differently under the three Reynolds numbers. With the increase of θ, the St value decreases in the laminar flow Reynolds number (Re=100); in the subcritical Reynolds number (Re=3900), the St value rises slightly at 45° and decreases significantly at 60°; the St value increases at the Reynolds number (Re=3.5*10⁶) of the supercritical.