Numerical Simulation of Drag Reduction Characteristics of Cylindrical Concave Based on Fluent

At present, the drag reduction effect of the bionic non-smooth surface is very sensitive to the inflow angle, and the drag reduction effect can only be achieved when the inflow angle is within a certain range. In response to this problem, this article is inspired by the concave microstructure of the insect body surface of the Cybister bengalensis and proposes a cylindrical concave drag reduction technology. Firstly, a numerical model of the cylindrical concave surface drag reduction characteristics is established, and then a numerical simulation analysis is carried out using Fluent software to study the concave surface drag reduction effect and the drag reduction mechanism, and further analyze the influence of the inflow angle and turbulence energy on the cylindrical concave surface drag reduction rate. Finally, It is concluded that: (1) Under the given simulation model, the concave surface has a better drag reduction effect than the smooth surface in a larger speed range, and the maximum drag reduction rate is 6.0%. (2) The concave surface structure has a better drag reduction effect than a smooth surface. Incoming flow in all directions has the ability to reduce drag. (3) When the flow velocity of the fluid is within the range of 1-20m/s, under different inflow angle conditions, the concave structure can achieve drag reduction, and the drag reduction rate is within 10%.