Development of mathematical model of Universal modeling method for centrifugal compressors calculation

¹ Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya 29, Saint Petersburg, 195251 Russia
² Lodz University of Technology, Institute of Turbomachinery Wolczanska 219/223 Lodz, Poland 90-924

^* Corresponding author: a_drozdi@mail.ru

Abstract

The heart of the Universal modeling engineering method is the physical model that is based on flow visualization and measurements inside rotating impellers. The experience of its application allowed finding ways of mathematical model development. The loss of a head is a function of flow gradients along a surface and along a normal to it. Necessary calculations were 1-D in the previous models. Quasi-three-dimensional approach is applied in the new model. A new loading factor model was applied. It determines characteristics by the angle of inclination and the value of the loading factor at zero flow rate. This made it possible to abandon the choice of empirical coefficients. A new loss of head model in a vaneless diffuser based on the results of CFD calculations generalization is used. The new model allowed abandoning a number of empirical coefficients of the mathematical models. Identification of the new mathematical model by the characteristics of model tests of centrifugal compressor stages was made. The efficiency calculation accuracy was sufficient for the engineering method.