In the present study, an improved heat exchanger model is proposed to efficiently analyze the cold oil removal process inside a fuel-cooled oil cooler. When exposed to low temperature condition, oil within a heat exchanger begins to congeal, preventing oil flow and causing loss of cooling. The conventional heat exchanger models, however, shows limits in reflecting the highly varying viscosity effects due to large temperature difference. To overcome this, the conventional porous media model was rewritten with the friction and Colburn j-factors that include the temperature dependent property variation. The property correction method by Shah and Sekulic [31] was added to enhance the prediction accuracy. Also, a relief valve model based on the porous media approximation is developed. The developed models were validated against the experimental data. Transient three-dimensional numerical simulations are carried out to analyze the effects of operating conditions on de-congealing phenomenon inside the FCOC.

在本研究中，提出了一种改进的换热器模型，以有效地分析燃油冷却的油冷却器内的冷油去除过程。当暴露在低温条件下时，热交换器内的油开始凝结，从而阻止油流动并导致冷却损失。然而，常规的热交换器模型在反映由于大的温差而引起的高度变化的粘度效应方面显示出局限性。为了克服这个问题，常规的多孔介质模型被改写为摩擦和Colburn j因子，其中包括与温度有关的特性变化。添加了Shah和Sekulic [31]的属性校正方法以提高预测准确性。此外，建立了基于多孔介质近似的安全阀模型。根据实验数据验证了开发的模型。