Leakage study of a lubricant-free revolving vane compressor

Abstract

This study presents an approach to study the three-dimensional internal leakage gas flow occurring in a lubricant-free revolving vane compressor. In this study, the two-dimensional analytical analysis was first carried out using Fanno flow through the leakage paths. This is then expanded by computing the equivalent width of the leakage path which was obtained from a comprehensive three-dimensional computational fluid dynamics model, to form a three-dimensional analytical leakage flow model. Thereafter, measured data from the physical prototype was collected and used to formulate a set of effective leakage flow coefficients. The resultant three-dimensional leakage model was then used to predict the internal leakage flow in the lubricant-free compressor. The results show that the proposed three-dimensional internal leakage model was able to predict the internal leakage of the compressor within discrepancies of ±15%. Subsequent studies show that with better machining tolerance control, a practical volumetric efficiency above 90% can be achieved by the lubricant-free revolving vane compressor.