Optimization of the Tooth Profile Parameters of Hypocycloidal Cylinder Based on Stability Analysis of Flow Around 2020-01-5049

The design and optimization of the tooth profile of the hypocycloid cylinder mostly adopt a two-dimensional geometrical method. The flow around the cylinder is modeled by the COMSOL software platform and compared with the experimental results; the two-dimensional numerical simulation of the flow around the hypocycloid cylinder is carried out by using the flow around the cylinder. The distribution of eddy current around the tooth profile and the variation of pressure coefficient, lift coefficient, and drag coefficient are analyzed. Then the relationship between the best tooth profile and the tooth profile parameters is established by analyzing the flow stability of the tooth profile under different tooth numbers and parameters. The results show that the boundary layer separation mainly occurs at the top of the teeth and the curvature of the top of the teeth is different under different parameters, which results in a variation of boundary layer separation, and thus affecting the development of the wake vortices. The tooth top width decreases with the increase of its generating coefficient and arc radius coefficient, resulting in the increase of energy consumed to resist the inverse pressure gradient and the decrease of drag coefficient. Because of the fluctuation of vortex shedding, the lift coefficient changes periodically. The variation of boundary layer separation, lift, and drag with the tooth profile parameters will affect the development of wake vortices. By analyzing the relationship between the tooth profile when the flow stability is optimal and the tooth profile parameters, the optimized tooth profile parameters are obtained. By comparing with the optimization results of literature [5], the optimized tooth profile in this paper is smoother, more stable in operation and meshing, and more stable in operation, the force is smaller. This research method can also be used as a reference for the optimization design of other fluid machinery equipment.