Optimizing the Thermodynamic Performance of the Fuel/Lubricating Oil Heat Exchanger for an Aeroengine

HTRI xchanger Suite 6.0 software was employed to analyze the thermodynamic performance and thermal resistance distribution of the fuel/lubricating oil heat exchanger A for an aeroengine. Calculated results demonstrated good agreement with experimental results for both heat transfer and flow resistance characteristics. The thermal resistance analysis revealed that the tube-side contribution dominated, accounting for 84.6% of the total resistance. The whole aeroengine test revealed that insufficient tube-side velocity resulted in prolonged fuel filling time, subsequently delaying fuel ignition and affecting aeroengine starting. To address these issues while maintaining lubricating oil cooling requirements, a structural optimization incorporating twisted tape inserts was proposed. It was calculated by HTRI software that when the twist ratio and the thickness of twisted tape inserts was 4 and 0.5 mm, respectively, the optimized fuel/lubricating oil heat exchanger B demonstrated remarkable performance improvements, with an 82.6% reduction in total thermal resistance, a 213% increase in overall heat transfer coefficient, and an 18.0% reduction in total mass. A subsequent whole aeroengine test at the performance evaluation point confirmed that heat exchanger B successfully met all technical requirements of total mass, flow resistance, heat transfer rate, and aeroengine starting, simultaneously. The demonstrated methodology presents significant potential for broader aerospace thermal management applications, such as performance prediction of enhanced heat exchangers, multi-objective optimization of thermal systems, and integrated thermal management solutions.