Modification and validation of twozone model in centrifugal compressor

In onedimensional preliminary design of centrifugal compressor, high accuracy performance prediction could shorten the design cycle and improve the design efficiency. In order to improve the accuracy of performance prediction, a model of diffusion ratio based on the conventional twozone model was proposed with consideration of the effects of import external energy and impeller rotation. The twozone model was used in prediction of vaneless diffuser performance prediction by taking account of characteristics of vaneless diffuser. Validation of the model was performed against compressor maps and geometries available in the literature. The results showed that it could effectively reduce dependence on engineering experience by using the proposed model, and could be suitable for predicting performance of centrifugal compressor with different pressure ratios and backsweep angles. Predicted performance by the proposed model agreed fairly well with experiment and the percent difference was within 4%.