The Predicting Method For The Preformance And Onset Of Surge Of The Highly Loaded Fan/Compressor

The predicting performance and onset of surge of the highly loaded fan and compressor havethe meaning of engineer during its design processing. Based on the need of this, the research onthe two-dimension numerical method for the highly loaded fan/compressor performance and onsetof surge predicting has been done.The cascades on different height of rotor and stator in highly loaded two-stage fan have beennumerically simulated, aiming to analyze its characteristics. The off-reference deviation and lossmodel have been obtained; The two-stage fan was simulated with different rotational speeds usingthree-dimension calculation, the rotor in first stage and the first stage were singly calculated.Analysis of the fan performance changes and the distribution of flow parameters along the radiusdirection were done. According to the comparison of the cascade characteristics in two-dimensionand three-dimension calculation, Analysis of the three-dimensional effect on deviation and losswas done. The changes of fan performance, the distribution of flow parameters and the onset ofsurge in different tip clearances, Analysis of coefficient of maximum static pressure rise changeswith different radius tip was also done.Research on predicting performance and onset of surge of the highly loaded fan andcompressor using semi empirical and semi theoretical method, based on the numerical calculationhas been done. The research include analysis code on meridian surface, deviation and loss model,onset of surge predicting method. The two-stage fan was simulated by elementary cascade method,the rotor in first stage and the first stage were singly calculated. Analysis of the fan performancechanges and the distribution of flow parameters along the radius direction were done, at the sametime, the onset of surge was predicted. According to the comparison of three-dimensioncalculation and elementary cascade method calculation, it indicates that the elementary cascademethod can reflect highly loaded fan the changes of performance and the onset of surge properly.To obtain more accurate result, a quantity of numerical calculation and experiments are needed,which can improve deviation and loss model.