Pressure pulsation prediction by 3D turbulent unsteady flow simulation through whole flow passage of Kaplan turbine

Purpose - The purpose of this paper is to predict pressure Pulsation in Kaplan hydraulic turbines. Design/methodology/approach - State of the art numerical simulation techniques are employed to simulate three-dimensional flows in the whole flow passage of a Kaplan turbine so that pressure pulsations can be computed in both time domain and frequency domain. Numerical results are verified by experiments carried out on the most advanced experimental platform in China. Findings - It is found that the proposed numerical model is a viable tool for prediction of pressure pulsations. The simulation shows that the model turbine and prototype turbine have the same pressure pulsation frequencies and rotating frequencies and the same transmission patterns under similar operation conditions. However, there is no similarity for the amplitude of the pressure pulsation between the model turbine and the prototype turbine. Therefore pressure pulsations in a prototype turbine cannot be obtained by scaling the experimental results of the model turbine using a similarity relationship. Practical implications - The findings will be very valuable for the design of hydraulic turbines and large-scale hydraulic power stations. Originality/value - The proposed numerical method provides a viable tool for hydraulic turbine and power station designers to predict the pressure pulsations in prototype turbines. It is a useful tool to help improve the performance of hydraulic turbines. The findings made in the numerical simulation have been verified by experiments, which is also a valuable reference for hydraulic turbine designers.