Research on the calculation method of engine allowable environment temperature

To obtain the subcompact engine´s permissible environment temperature, wind tunnel test and numerical simulation methods were respectively adopted. The subcompact radiator´s heat dissipation potential was calculated by matching analysis of radiator and cooling fan. And therefore the allowable environment temperature at the rated power mode was calculated. The error between the numerical simulation method and experimental method is small, which verifies the numerical simulation method for allowable environment temperature research is feasible. Through the example, a complete set of allowable engine ambient temperature calculation method by simulation was gained, which includes the matching of radiator and cooling fan, the amendment of inlet air flow, the analysis of radiator heat exchange performance, and the calculation of allowable ambient temperature by preceding results. The research results have some directive significance for improving vehicle virtual design capability.