Performance prediction modeling of variable cross-section scroll compressor for electric vehicles

• A scroll compressor with variable thickness was designed via equidistant normal. • Response surface method analyzed effects of parameters on compressor efficiency. • A CFD–RSM model was proposed to predict isentropic and volumetric efficiencies. In this study, a variable-thickness scroll compressor was developed using the equidistant normal method, featuring a hybrid profile composed of circular involute–variable base circle involute–circular involute curves. To predict performance, numerical simulation was combined with response surface methodology (RSM) to establish regression models for isentropic efficiency and volumetric efficiency. An experimental investigation was conducted to validate the simulation results, the maximum deviation between simulated and experimental values of volumetric efficiency was 2.3 %, and that of discharge temperature was 3.2 K. Spatial response surfaces revealed strong nonlinear interactions among operating parameters. The results indicate that the interaction between suction and discharge pressure had the greatest influence on isentropic efficiency, while discharge pressure and rotational speed were dominant for volumetric efficiency. The optimal operating conditions were determined as 304.44 K, 0.35 MPa, 2.16 MPa, and 3933.85 r·min −1 for suction temperature, suction pressure, discharge pressure, and speed, respectively. Under the optimized conditions, the simulated isentropic efficiency and volumetric efficiency improvements of 8.01 % and 1.7 % compared to the rated operating conditions. The predictive accuracy of the regression models was validated through numerical simulation. The deviations between predicted and simulated values for both isentropic and volumetric efficiencies were found to be less than 5 %, confirming the reliability of the performance prediction models of variable cross-section scroll compressor for electric vehicles