Abstract. Clean gas engines, such as liquefied petroleum gas (LPG)
engines, have high thermal loads on parts under equivalent specific
combustion. This study examines the multi-field coupling enhanced heat
transfer principle and its applications to the engine compartment of a
typical LPG city bus. The field synergy enhanced heat transfer principle
(FSP) was applied in the radiator assembly area. The FSP model yielded an
optimum velocity -temperature gradient matching field that would improve
convective heat transfer in this area. To strengthen the convective heat
transfer ability of the limited cooling air in the cabin, temperature field
homogenization (TFH) in the core flow region of the engine block area was
achieved. The TFH optimization model helped minimize the temperature
gradient in the core flow region and maximize it at the heat transfer
boundary, and the optimum vector field and flow path were obtained. More
comprehensive changes to the structural design were made according to the
multi-field coupling enhanced heat transfer principles. The simulation
results showed that in the comprehensive structure, the heat transfer
efficiency of the radiator increased by 14.66 %, the average temperature
of the air passages in the engine block area decreased by 22.23 %, and the
heat dissipation coefficient of the engine body and engine cover increased
by 4.60 times and 3.49 times, respectively.