Leakage Characteristics of Scroll Compressor by Two Phase Flow Model in Consideration of Wall Oil Film Thickness.

Abstract

Two-phase leakage model in consideration of the film thickness on the wall surface has been proposed to improve the estimation accuracy of the leakage in a scroll compressor. The oil adhesion rate was introduced as a parameter which gives the probability that the oil in a compression chamber adheres to the scroll wall surface. In order to obtain the oil adhesion rate computationally, the flow in a scroll compression chamber was simulated by the MAC method which is a kind of non-compressing viscosity flow analysis, and the adhesion position to the wall surface was computed by tracking oil particles in a flow field. The average oil adhesion rate in the seal section was 0.21 by numerical computation. This means that 21% of the oil in a compression chamber adheres to the wall surface. The scroll leakage loss was measured for verification of the two-phase leakage model in two kinds of different suction volumes compressors. The rate of oil adhesion identified from the experiment result was 0.2 to 0.45. Leakage losses by experiments agree with the numerical results within 2% to 4%, so that the effectiveness of the two-phase leakage model were confirmed.