Numerical Optimization of the Defrosting Performance of the Vehicle Based on Discrete Adjoint Approach

In this study, the discrete adjoint approach with the grid deformation technique based on radial basis function was presented to solve the tough problem that the complex shape of the defrosting duct is very difficult to be optimized with multiple parameters in the improvement of the defrosting performance of vehicle. Firstly, the defrosting performance of a light truck was analyzed. Then the discrete adjoint approach was applied by taking the average Nusselt-number as the objective function. The normal surface sensitivity was used in the deformation of the defrosting duct. After 10 optimization cycles, the optimal model was acquired. The results show that, after optimization, the sum of the average Nusselt-number is increased from 3164.16 to 3350.54, which has a positive effect on improving the convection and heat transfer capacity on the windshield effectively. Compared with the initial model, the airflow of the outlet near the windshield is increased from 95.07 g/s to 96.94 g/s, the defrosting time required by the optimal model is reduced by more than 20s. Therefore, the discrete adjoint approach can optimize the complex shape of defrosting duct with multiple parameters effectively, which provides an effective method in the study of automobile defrosting performance.