Thermal insulation optimization of turbocharger bearing housing: A comparative study on heat shield configurations and ventilation strategies

As modern engine exhaust temperatures continue to escalate, turbocharger bearing systems face unprecedented thermal loading. The heat shield emerges as a critical thermal barrier in this context, directly impacting bearing housing protection. This investigation employs an integrated experimental-numerical methodology combining bench testing with conjugate heat transfer analysis to systematically evaluate two prevalent heat shield designs: inner-rim open versus closed configurations. Particular emphasis is placed on quantifying the thermal insulation efficacy of vent hole quantity and angular positioning. Key insights reveal: The inner-rim closed configuration demonstrates superior thermal resistance compared to its open counterpart, achieving comprehensive performance enhancement. Dual vent hole arrangements exhibit strong pressure differential dependence. When positioned at maximum ΔP locations, temperatures at turbine-end seal ring and floating bearing monitoring points rise 9.3K and 4.9K, respectively. Pressure-balanced dual vent configurations conversely reduce temperatures at these locations by 2.6K and 1.5K respectively. While optimized dual vent solutions achieve peak insulation performance, single vent designs show greater robustness against operational variability. This study establishes quantitative design guidelines for thermal management optimization in high-temperature turbocharger applications.