Session: 8.3.2 - Pumping Machinery II

Paper Number: 158093

158093 - Research on a Rapid Evaluation Method for Unsteady Characteristics of Centrifugal Pumps Based on the Steady Flow Field Structure 

Abstract: 

    Centrifugal pumps are widely used in energy, chemical, and other industries, and their unsteady characteristics are of great importance. Typically, the unsteady characteristics of centrifugal pumps are characterized by pressure fluctuations and radial force pulsations, which often rely on unsteady numerical simulations or experimental tests. These methods, however, require significant time and economic costs. Additionally, the implementation of intelligent optimization algorithms for centrifugal pumps, including neural networks and multi-objective genetic algorithms, is hindered when reliant on these costly unsteady numerical simulations or experimental tests. Consequently, there is an urgent need for a rapid evaluation method for the unsteady characteristics of centrifugal pumps.

    This study aims to explore the correlation between the steady flow field structure and the unsteady characteristics of centrifugal pumps. Through an in-depth analysis of the steady pressure field and velocity field, we identify a strong correlation between the spatial distribution of the steady pressure and velocity fields at the impeller outlet and the guide vane outlet, and the unsteady pressure fluctuations and radial force pulsations.

    Considering the internal flow characteristics of centrifugal pumps and numerical computation theories, an appropriate mesh generation scheme, turbulence model, boundary conditions, and discretization methods are selected to conduct both steady and unsteady numerical simulations of a guide vane centrifugal pump. A centrifugal pump test rig is constructed, and experimental tests are performed on the model pump. A comparative analysis between the experimental and numerical simulation results is conducted to determine the numerical computation method that meets the accuracy requirements of this study. Subsequently, the steady pressure field and velocity field, as well as the unsteady pressure fluctuations and radial forces for different blade shapes and numbers of guide vanes and impellers, along with various cross-sectional shapes of the volute are analyzed and a rapid evaluation method of unsteady characteristics of centrifugal pumps based on the spatial Fast Fourier Transform of the steady flow field structure is proposed.

    The research indicates that the spatial characteristic frequencies of the spatial spectrum obtained from the spatial Fast Fourier Transform of the steady flow field can represent the number of blades in the impeller and guide vanes. The amplitudes at these spatial characteristic frequencies can quantify the influence of the impeller and guide vane blade shapes on the unsteady characteristics of the centrifugal pump. Furthermore, under constant guide vane and impeller conditions, the amplitudes at these spatial characteristic frequencies can also reflect the impact of the volute's flow cross-section and outlet on transient performance. The findings of this study provide guidance for the rapid assessment of unsteady characteristics and the development of intelligent optimization in centrifugal pumps.

Presenting Author: Xinxiang He Zhejiang University

Presenting Author Biography: Xinxiang He is currently a Doctor’s degree candidate in the Institute of Advance Equipment, College of Energy Engineering, Zhejiang University. His research focuses on the design of pumps with low vibration and noise.