Fluid-solid coupling field analysis of centrifugal fan based on nonlinear dynamics

Abstract

According to the characteristics of Fluid-solid coupling flow field of centrifugal fan, fan aerodynamic performance signal collecting experiment under different conditions are carried out on the centrifugal fan test bed. The relationship among airflow pressure pulsation, noise and vibration are studied by using nonlinear dynamics methods such as phase space reconstruction, correlation dimension, and complexity and so on, which lays the foundation for predicting the fan running status by monitoring the signal of airflow pressure pulsation and the noise. The result shows that the phase diagram of airflow pressure pulsation signal attractor is the most distinct and regular among the three signals. The scope of the phase diagram increases and becomes sparse and confusing with the decrease of the flow, which reflects that pressure pulsation amplitude becomes larger and the internal flow deteriorates gradually with the decrease of flow. The correlation dimensions are calculated with G-P algorithm of the three signals first decrease and then increase with the decrease of the flow. The correlation dimension of the airflow pressure pulsation or noise under stall operating condition can be used as monitoring indicators. The L-Z complexity of the noise increases constantly with the decrease of the flow. But the L-Z complexity of airflow pressure pulsation and vibration first decreases and then increases with the decrease of the flow.