Abstract:

Occupant compartments of special-purpose vehicles undertaking specialized missions frequently face challenges of uneven thermal distribution. To optimize the thermal environment while enhancing human thermal comfort and operational efficiency， in this study a CFD model for a special-purpose vehicle cabin is established. The validity of the CFD model is verified through simplified cooling tests in an environmental chamber. Three human thermal comfort metrics， average occupant skin temperature， head-to-foot temperature difference， and average PMV （predicted mean vote）， are employed as evaluation criteria. Simulation is conducted on three distributed air supply configurations with a single return vent under cooling mode： single-supply/single-return， triple-supply/single-return， and quintuple-supply/single-return. The results show that the quintuple-supply/single-return configuration with personalized air supply vents positioned 100 mm above each occupant’s head significantly enhances cooling effectiveness， reducing the maximum temperature difference in average skin temperature by 2.9 ℃， improving temperature uniformity within the occupant compartment （with head-to-foot temperature difference decreased by 0.3 ℃）， and markedly improving human thermal comfort （with PMV reduced by 1.9）. The findings provide critical insights for optimizing air supply/return systems in special-purpose vehicle occupant compartments， supporting the design of healthy and comfortable high-quality cabin environment.

Key words: special-purpose vehicles, occupant compartment, human thermal comfort, CFD model, distributed air supply