A pseudo-transient modeling for developing gear transmission casing with efficient heat dissipation

The limited heat dissipation performance of the casing restricts the power density growth in gear transmission system without active cooling. Meanwhile, the complex multiphase heat-flow of the casing presents a challenge to the performance evaluation and heat dissipation improvement. To address this bottleneck, pseudo-transient heat-flow coupled modeling and triangular spacer ribs (TSRs) within the casing are proposed to predict multiphase heat-flow performance and enhance heat transfer with less flow friction losses (viscous heat), respectively. The model realizes both transient behavior prediction and steady-state performance evaluation of multiphase heat-flow by the thermal network model assisted CFD model. The results show that TSRs significantly enhance Nusselt coefficient (Nu) and reduce skin friction coefficient (C_f) under all operating conditions. The higher Nu of TSRs benefits from the flow separation and bearing vortices, which increase the near-wall temperature gradient. In addition, the bearing vortices and thicker lubricant layer between TSRs reduce C_f by diminishing momentum exchange. Considering these factors, a full-condition optimization framework based on the reverse entropy weight assignment strategy is constructed to find the configuration parameters with the higher Nu and lower C_f for all operating conditions. Compared without TSRs, the optimized TSRs enhances Nu by 28–42 % under all operating conditions, while reducing C_f by 32–48 %.