Enhancing Flow Field Performance of a Small Circulating Water Channel Based on Porous Grid Plate

Low-cost and high-efficiency circulating water channels are widely used in the hydrodynamic tests of an underwater device. The current research mainly focuses on obtaining a better velocity uniformity of the test section by optimizing the curve function of the boundary in the contraction section. While, for small underwater device, their hydrodynamic characteristics are sensitive to turbulence. Thus, the circulating water channel, which can obtain the required turbulence characteristics, is urgently needed. A small circulating water channel, which can reduce the turbulence intensity based on a porous grid plate and can be used to test the hydrodynamic characteristics of a small underwater device, is designed. The relationships between porosities and resistance coefficients of a porous grid plate are established. The effects of the honeycomb (porosity and thickness); screen (porosity, number of layers, and spacing); and pumping flow rate on the turbulent characteristics of the test section are studied. The relationships between the parameters and the turbulent characteristics of the test section are established, and the methods to achieve the required flow characteristics of the test section are proposed. Experiments are carried out, and the validity of the obtained results is verified. In this work, the turbulence intensity of the fluid field in the test section can be restrained to 0.0491, which is enough to meet the turbulence requirements for the hydrodynamic test of a small underwater device. This work can provide references for the construction of a hydrodynamic test platform for small underwater devices.