Papers by Author: Yan Xu

Abstract: To improve accuracy and efficiency of the hydraulic design of the guide vanes of the multistage centrifugal pumps, four different-structured guide vanes are investigated, and the design processes of those systems are established. The secondary development platforms of the ObjectArx2000 and the UG/NX OPEN are utilized to develop the hydraulic design systems of the guide vanes. The error triangle method is adopted to calculate the coordinates of the vanes, the profiles of the vanes are constructed by Bezier curves, and then the curves of the flow areas along the flow-path are calculated. Two-dimensional and three-dimensional hydraulic models can be developed by this system.

Abstract: The performance curves of a submersible axial flow pump were predicted based on mixture multiphase flow model, RNG k-ε turbulence model and SIMPLEC algorithm, and the solid-liquid two-phase flow in the impeller was simulated. The numerical results show that the performance prediction of the head and efficiency curves show good agreement with the experimental data in the whole flow rate range, and the solid particles in the impeller are mainly distributed on pressure side of blades, while less on the suction side.The solid particles are mainly concentrated in the blade inlet and region near the hub of the pressure side. The experimental results also show that the blade pressure sides have serious erosion, particularly near the hub, but less wear and tear on the suction side.The accuracy of the numerical simulation results are verified by the experiments.

Abstract: Multi-stage centrifugal pumps for mining are widely used in mining and smelting industry. The operational environment in coal mine sewage is very harsh, so pump shaft and bearing failure happens frequently. In order to avoid disaster damage caused by failure of the pump shaft due to resonance, it is quite necessary and urgent to calculate critical rotation speed of the pump shaft. A calculation program of critical rotation speed for multi-stage centrifugal pumps for mining was developed using the secondary development tool of Object ARX, to give the computational method of the pump shaft load and static deflection and to achieve calculation of the critical speed, and which avoided the disadvantage of the traditional method. The practical application indicates that the program of critical rotation speed is convenient, intuitive and calculation accurate. It not only improves the work efficiency, but also reduces the labor intensity, so the program will have a good application prospect.

Abstract: In order to research the effect of the blade wrap angle and outlet angle on the hydraulic performance of the low-specific speed sewage pump, the Reynolds time-averaged Navier-Stokes equations was discretized based on the finite volume method, and the modified k-ε turbulence model were chosen in FLUENT. Numerical simulation of the internal flow within the centrifugal pump with the specific speed of 60 at different blade wrap angle and outlet angle is carried out. The analysis of the velocity and the turbulent kinetic energy distribution in different cases, and predicts the external characteristics of the several cases based on the loss analysis method. The study results show that the efficiency of pumps increase with decreasing the outlet angle and increasing the wrapping angle at the design of sewage pumps. According to the analysis, changing the blade outlet Angle has much more influence on the performance of the pump than changing the wrap angle.

Abstract: In order to develop stamping well pump with high efficiency, 4SP14 stainless steel stamping well pump was set as an example. Combined with the features of stamping technology, this research was taken on raising the efficiency of stamping well pump, using hydraulic design of impeller and CFD and regression test method. The experiment was designed with four factors including impeller inlet angle Δβ1, impeller outlet angle β2, and impeller outlet width b2 and inlet width of guide vane B3. 30 groups of programs were designed according to CCD central composite test method. The whole flow field of well pump at the operating point was simulated by FLUENT using the standard k-ε model, SIMPLE algorithm, first-order upwind scheme. 30 group of efficiency were obtained. Use regression equation to fit the function relationship between the efficiency value and each factor. Through the analysis of the regression equation, the optimal combination of geometric parameters can be found as inlet angle 4º, outlet angle 27.5º, outlet width 9.5mm and inlet width of guide vane 11.5mm. After manufactured and tested according to the above geometric parameters, the efficiency of the optimal model pump reaches 60.28%, which reaches the international advanced level.