## 1 Introduction
[18], on the basis of previous research, put forward a theoretical calculation model, which is the calculation of the solid particles in the mud flow of tube wall erosion situation, and found that the erosion rate and average mud speed is very closely related, and the pipe diameter and fluid viscosity hedge the impact of corrosion rate is lesser, and the results also show that there is an exponential power relationship between erosion rate and average mud velocity, pipe diameter, particle size and fluid viscosity. [PERSON] [19] studied the erosion wear mechanism of tee tubes in-depth based on CFD; his research showed that under the confluence effect, the higher the gas flow rate in the tee, the lower the pressure, and the more likely the section is to suffer severe erosion. Based on the DPM erosion prediction model, [PERSON] et al. [20] studied the erosion wear of a new high-pressure manifold quick connection device on the surface of some well sites. [PERSON] et al. [21] studied the bubbling characteristics and separation of multi-component particle mixtures in fluidized beds by using a dense discrete phase model combined with particle flow mechanics theory and experiment. [PERSON] et al. [22] took the vertical grinding machine as the research object, applied the method of combining experiment and simulation, solved the particle motion trajectory with the bidirectional coupling calculation method of discrete phase model DPM and analyzed the mutual coupling effect of two-phase flow in the vertical grinding flow field and the particle classification and screening characteristics from the aspects of velocity, pressure and discrete phase distribution. In terms of numerical simulation and experimental research on turbine wear, [PERSON] et al. [23] carried out full flow channel numerical simulation on a Francis turbine by using VOF model and DPM model, and analyzed the sediment distribution and solid-liquid two-phase velocity on runner blade surface under different working conditions, which provided a theoretical basis for the transformation of turbine in this power station. [PERSON] [24] established a CFD-DPM model to investigate the erosion of 90\({}^{\circ}\) elbow in a shale gas field under gas-solid two-phase flows, His findings include the influence of six factors on the maximum amount of erosion which including gas velocity, mass flow rate of sand particles, particle diameter, shape coefficient of sand particles, pipeline diameter, elbow radius of curvature. [PERSON] and [PERSON] [25] used a CFD-DPM method which is based on Euler-Lagrange method and erosion model to study the flow erosion of sand-bearing oil flow in the U-bend. The finding shows that the maximum erosion part occurs on the outer elbow, the lower surface of the elbow and the downstream pipe. [PERSON] et al. [26] carried out numerical simulation and sediment wear test on the turbine of Hatta Hydropower Station, and predicted the sediment wear of the turbine, which provided an important reference for the anti-wear design and operation of the turbine of Hatta Hydropower Station. [PERSON] et al. [27] applied the wear model and DPM model to simulate the stay vane of a certain type of turbine, and the wear rate on the surface of the guide vane of the numerical simulation results are compared with the experimental data, the forecast and verified the turbine guide vane fixed under the rated conditions of wear situation of fixed for the turbine guide vane abrasion in the late design provides reference basis. As a large hydraulic conservancy structure, the operating environment of the spillway is relatively complex; there are many factors that affect the sand flow, such as sand diameter, concentration, flow rate, gate opening and so on. It is difficult, through the prototype observation and in-situ experiment methods, to study the erosion wear characteristics.