Numerical Analysis of an Automobile Cabin Thermal Management using Passive Phase Change Material

Abstract Nowadays, efforts are being made to reduce HVAC load in vehicles and maintain comfortable temperatures within the cabin, predominantly owing to extreme weather conditions, particularly during the hot summer season. Solar radiation increases heat transfer in vehicles. In addition to the greenhouse effect, it adds significantly to increasing heat content inside the vehicle's cabin, thus increasing temperature. Thus, there is a need for thermal management of automobiles, which could be achieved using utilizing latent heat storage materials, such as Phase Change Materials (PCMs). Present research focuses on computational fluid dynamics simulations for evaluating performances of four PCMs – OM 29, HS 24, Bio Q27 and CaCl2.6H2O in thermal management of vehicle’s cabin for a short duration of time (120 seconds). Accordingly, most appropriate PCM is selected based on the results achieved in terms of temperature reduction, difference in temperature achieved and standard comfortable temperature, and melt fraction for further analysis of cabin for a longer duration (3600 seconds). Results revealed that within 120 seconds, PCM incorporation facilitates cabin temperature reduction of approximately 7 K. Moreover, CaCl2.6H2O proved to be the most suitable amongst four PCMs studied, based on the criteria mentioned above for the given environment conditions. Hence, its performance is further explored for a period of 1 hour, that resulted in reducing cabin’s peak temperature approximately by 33 K.