Study on flow measurement method of vertical axial flow pump based on the relationship between flow and differential pressure of two points in elbow inlet passage

Under the support of computational fluid dynamics (CFD), a new flow measurement method for vertical axial flow pump with elbow inlet passage was put forward. In order to select suitable turbulence model to predict wall pressure in elbow inlet passage, Standard k-ϵ, RNG k-ϵ and Realizable k-ϵ models were used to simulate the flow field. In comparison with experimental results, the conclusion could be drawn that it is feasible to predict the wall pressure of elbow inlet passage with Realizable k-ϵ turbulence model. For model pump, based on the data from the model test and the numerical simulation respectively, the equations about discharge of pump and two-point differential pressure were obtained with the least square method and the results indicated that coefficients of the equations were slightly different. Based on the same numerical simulation method as model pump, the differential pressures were obtained by cloud computing with large parallel for prototype pump. In order to improve the prediction accuracy of discharge of prototype pump, a new corrected method was proposed on the condition that the relative errors about two-point differential pressures between numerical simulation and experiment for model pump were the same as those for prototype pump according to Euler similarity criterion. It is concluded that the method improves the accuracy and simplicity of flow measurement for vertical axial flow pump with elbow inlet passage and the approach to predict the flow of pump is feasible.