Performance of the hydrogen fuel cell system in a compact special vehicle is mainly influenced by the thermal characteristics of heat release through air flow with electrochemical mechanisms. In this study, numerical analysis has been carried out to investigate air flow and heat transfer characteristics near the fuel cell system for various operating conditions. The cooling characteristics around the radiator system depend on air flow generated by vehicle movement, and the effects of vehicle-induced air flow on the velocity and temperature distributions within the heat release system were examined. These results showed that there are quite complicated air flow around the radiator and fan near the fuel cell system in the vehicle cargo area, and its efficient flow field resulted in cooling performance improvement with driving speed. Hence overall heat release characteristics of the hydrogen fuel cell system are strongly associated with various air flow behavior formed around the compact special vehicle including cargo area.

Numerical analysis has been performed to investigate the stress distribution characteristics of auxiliary axle system in a compact special vehicle. Structural and running stability of compact special vehicle is largely affected by auxiliary axle system installation. Structural characteristics of stress and deformation distributions with safe factor in the auxiliary axle system are analyzed. It can be seen that maximum stress happens near the local axle position, and deformation is also predicted. Simulation results are also compared with experimental test data. These results from this study could be applicable for optimal design of diverse axle systems in the compact special vehicle.

Numerical analysis has been carried out to investigate the structural characteristics of auxiliary shaft system in a compact special vehicle. Stress and deformation distributions with safe factor in the auxiliary axle system are compared. It can be seen that maximum stress happens near the local axle position and deformation at the air spring is also predicted. The results from this study could be applicable for optimal design of variable shaft system in the compact special vehicle.