Analysis and Judgment of the Local Loss Based on the Entropy Gradient

Abstract

Analysis of the flow loss is important in the turbomachinery, the current analysis methods based on the cumulative loss such as the total pressure loss coefficient and the adiabatic efficiency, and the local loss method reflect the loss, can’ t quickly reflect the physical principles that leads the loss and its’ development. To solve this problem, the paper based on the first and second laws of thermodynamics, a local losses model about the compressor internal flow was estimated using the entropy gradient, give a dimensionless loss function parameter I , and was verified in a three-dimensional numerical simulation about Rotor67. The numerical results show that: the model can quickly capture the magnitude and location of loss, it also can reflect the loss source, when the dimensionless parameter , the area is considered as an high loss area, the local loss is expressed as I. If the parameter near the wall for negative value indicates that reflux occurred.