Aerodynamic and Thermomechanical Optimization of Turbocharger Compressor Wheels for Improving Energy Conversion Efficiency

Abstract

This study addresses the engineering problem that turbocharger compressor-wheel performance is often optimized through separate aerodynamic, geometric, structural, thermal, and material analyses, although these factors interact directly in determining useful pressure development, irreversible loss, structural stability, and energy conversion efficiency. The purpose of the research was to quantify the individual and combined effects of Aerodynamic Flow Optimization (AFO), Geometric Configuration Optimization (GCO), Thermomechanical Structural Optimization (TSO), and Thermal Deformation and Material Optimization (TDMO) on Energy Conversion Efficiency (ECE) in high-speed automotive turbocharger compressor wheels. A quantitative, cross-sectional, case-study-based design was adopted, using purposive expert sampling and a structured five-point Likert questionnaire administered to technically qualified engineering professionals. Of 320 questionnaires distributed, 298 were returned and 286 valid responses were retained, yielding an effective response rate of 89.4%. Data analysis included descriptive statistics, reliability and validity assessment, Pearson correlation, and multiple linear regression, with significance evaluated at p < .05. ECE recorded the highest mean score (M = 4.22, SD = 0.50), while AFO, GCO, TSO, and TDMO achieved means of 4.18, 4.15, 4.12, and 4.09, respectively. All predictors were positively associated with ECE, with correlations of r = .74 for AFO, r = .71 for GCO, r = .68 for TSO, and r = .65 for TDMO, all p < .001. The combined model explained 71.2% of the variance in ECE (R² = .712, adjusted R² = .708, F (4,281) = 173.69, p < .001). AFO was the strongest predictor (β = .31), followed by GCO (β = .28), TSO (β = .24), and TDMO (β = .21), all p < .001. The findings indicate that compressor-wheel efficiency is best understood through an integrated optimization framework in which aerodynamic loss reduction is reinforced by geometric refinement, structural integrity, thermal stability, and material performance, offering practical guidance for energy-efficient and reliable turbocharger design.