Constructal design of heat sources with different heat generation rates for the hot spot mitigation

•Discrete heat sources generating different amounts of heat is considered.•The optimum heat generation ratio is determined by using constructal design method in order to mitigate the hot spot.•The dimensionless global conductance of the IC pack is calculated. This work aims to determine the optimum heat generation ratio among discrete heat sources generating different amounts of heat in order to mitigate the hot spot. Six different heat generation ratios are considered by following the constructal design method. For comparison, the average and total heat sources’ heat generation rates are kept equal for every examined cases. Meanwhile, Reynolds number ranges from 792 to 3962. All the three heat transfer mechanisms are taken into account with an integrated approach to calculate precisely the dimensionless global conductance of the IC pack. Three dimensional simulations are done with ANSYS Fluent while measuring surface temperatures in experiments. The output parameters of the study are the surface and hot spot temperatures, Nusselt number and dimensionless global conductance change with Reynolds number and heat generation ratio. It is disclosed that relative decreasing heat generation rates are convenient for hot spot mitigation.