Method for calculating axial force of semi-open impeller of centrifugal compressor

Abstract

In order to overcome the defects that when the axial force of a semi-open impeller of an existing centrifugal compressor is calculated, the calculation precision is low, or the calculated amount is large, and consumed time is long, the invention provides a method for calculating axial force of a semi-open impeller of a centrifugal compressor. When the calculation method is implemented, only the pressure distribution of the front end surface of the impeller is supposed to meet a parabola distribution rule; assuming that the axial component of the impeller outlet speed is zero, the assumption conforms to the pressure distribution rule of most impellers, meanwhile, the influence of impeller back clearance and sealing position is considered, the correction coefficient is obtained through a large number of experiments, and the calculation precision is high; the method is a one-dimensional axial force calculation method based on impeller inlet and outlet and impeller back pneumatic and geometric parameters and adopting circumferential parameter averaging, the number of required pneumatic and geometric parameters is small, and the calculation amount is small. The method has good universality, and axial force calculation can be conducted on the semi-open centrifugal impeller of the gas compressor with the low pressure ratio or the high pressure ratio through the method.

Description

technical field [0001] The invention relates to the technical field of centrifugal compressors for gas turbine engines, in particular to a method for calculating the axial force of a semi-open impeller of a centrifugal compressor. The method uses circumferentially averaged one-dimensional parameters to calculate the axial force. and geometric parameters, the amount of calculation is small; this method has good versatility, whether it is a compressor semi-open centrifugal impeller with a low pressure ratio or a high pressure ratio, this method can be used to calculate the axial force; this method only uses The assumption of the parabolic distribution of the pressure at the front end of the impeller is in line with the pressure distribution law of most impellers, and the influence of the gap on the back of the impeller and the position of the seal is considered, and the correction coefficient is obtained through a large number of experiments, and the calculation accuracy is high....

AI Technical Summary

Problems solved by technology

The low calculation accuracy of the axial force will cause the axial force on the bearing to exceed its bearing range or the axial force is too small to cause the bearing to be lightly loaded, which will accelerate the wear of the bearing and affect the safe operation of the engine rotor. Therefore, the centrifugal impeller suffers The accurate calculation of axial force is directly related to the reliability and safety of engine operation

[0003] At present, the axial force calculation method of the semi-open impeller of the centrifugal compressor is based on a simplified calculation formula based on a large number of assumptions, and the calculation accuracy is low, which cannot meet the high-precision calculation requirements of the aero-engine; Numerical simulation method for flow field calculation. This method has a large amount of calculation and takes a long time. It belongs to the method used in the detailed design process, and some assumptions in the calculation will also have a great impact on the accuracy of the calculation results.

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