CFD-Based Thermodynamic Stability and Energy Performance Optimization of a Refrigerated Truck Compartment Using Experimental Validation and Surrogate Modelling

This study presents an integrated computational framework combining Computational Fluid Dynamics (CFD), experimental validation, and surrogate modelling to analyse and optimise the thermal performance, thermodynamic stability, and energy efficiency of a refrigerated truck compartment. CFD simulations were conducted to investigate airflow distribution and temperature uniformity under operating temperatures ranging from 0 to 5 °C. The results showed that airflow circulation was primarily governed by the evaporator outlet, while recirculation zones enhanced air mixing but were insufficient to completely eliminate localised hotspots. Increasing the operating temperature from 0 to 5 °C resulted in a rise in the maximum compartment temperature from 6.26 to 10.01 °C. Thermodynamic stability analysis revealed that operation within the 3–5 °C range provided more stable thermal conditions due to reduced refrigeration load and improved temperature uniformity. Experimental measurements of airflow velocity and evaporator surface temperature demonstrated good agreement with CFD predictions, confirming the reliability of the numerical model. Furthermore, CFD-based optimisation reduced the electrical energy consumption of the eTRU system by 10.0%, decreasing the energy intensity from 0.117 to 0.105 kWh km−1, while maintaining improved thermal stability throughout the refrigerated compartment. The surrogate model achieved excellent predictive performance with R2 = 0.9576 and RMSE = 0.0386, demonstrating its suitability for rapid optimisation of refrigerated transport systems. The proposed framework offers an effective tool for improving thermal management, enhancing energy efficiency, and supporting the development of sustainable refrigerated transport systems.