The appearance and development of additive manufacturing technology promotes the production and manufacture of parts with more complex designs and smaller sizes and realizes the complex topology that cannot be made by equal-material manufacturing and submanufacturing. Nowadays, the application of tri-periodic minimal surface (TPMS) in topology optimization design has become a new choice, and, because of its excellent structure and properties, has gradually become mainstream. In this paper, the mechanical properties of four different topologies prepared by selective laser melting (SLM) using 316L stainless steel powder were investigated, including two TPMS sheet structures (Primitive surface, Gyroid surface) and two common lattice structures (Bcc lattice, truss lattice). The mechanical properties (Young’s modulus, yield stress, plateau stress, and toughness) were compared by numerical simulation and compression experiment. It can be concluded from the results that the mechanical properties and deformation mechanism of the specimen are mainly related to the type of lattice, though have little relationship with unit thickness at the same relative density. The Gyroid curved structure showed the best mechanical properties and energy absorption capacity, followed by the truss lattice structure. By comparison, the mechanical properties of the traditional Bcc lattice structure and the Primitive surface structure are poor, and the deformation mechanism of these two structures is uncertain and difficult to control.

This study considers a multi-stage sleeve control valve with different opening degrees. The flow capacity of the numerical model is calculated using the actual working conditions of the control valve in a nuclear power plant as a baseline. A flow resistance test bench is then used to measure the flow capacity under each opening degree, and the flow characteristic curve is plotted to verify the accuracy of the numerical model. Based on CFX software simulations of different opening speeds, pressures, turbulent kinetic energy clouds, and set detection curves, analysis of the flow characteristics of the multi-stage sleeve valve with high parameters shows that, with an increase in the degree of opening, the valve speed will also increase. However, the speed at the socket orifice is slightly different, exhibiting a higher opening in the middle and lower openings on both sides. A maximum speed of 792.4 m/s is found in the 40% valve orifice. A maximum value of the turbulent kinetic energy of 1.4 × 10 ⁴m²/s² occurs in the throttle hole of the valve seat with an opening of 80%. The source of the aerodynamic noise is obtained in this study, which is of great significance to the decompression and noise reduction in multi-stage sleeve valves.