Numerical Simulations of Hydraulic Characteristics of A Flow Discharge Measurement Process with A Plate Flowmeter in A U-Channel

Abstract

The use of a flow discharge measuring device in irrigated areas is the key to utilizing water in a planned and scientific manner and to developing water-saving irrigation techniques. In this study, a new type of flow discharge measuring device for a U-channel—a plate flowmeter—was designed, and then the hydraulic characteristics of the flow discharge measurement process using the plate flowmeter were simulated and experimentally verified by adopting an RNG (Renormalization Group) k-ε turbulence model based on Flow-3D software. The results showed that in the process of measuring flow discharge with the plate flowmeter, the transverse flow velocity, the vertical flow velocity, and the relationship between the measured flow discharge and the deflection angle of the angle-measuring plate were basically consistent with the experimental results. The maximum relative errors were 5.3%, 6.2%, and 6.8% respectively, proving that it was feasible to use Flow-3D software to simulate the hydraulic characteristics of the flow discharge measurement process using the plate flowmeter. The vertical flow velocities at the center of the upstream section of the channel increased gradually from the bottom of the channel to the free water surface. The vertical flow velocities at the center of the downstream section of the channel first increased and then decreased from the bottom of the channel to the free water surface, and the maximum vertical flow velocity was located at a position below the free water surface. The maximum range of influence of the plate flowmeter on the flow disturbance in the channel was from 0.75 m upstream to 1.24 m downstream of the plate flowmeter. These results can provide a theoretical basis for optimizing the structural parameters of a plate flowmeter.