Modeling particle deposition on the surfaces around a multi-slot diffuser

•A model for predicting particle deposition around a multi-slot diffuser was proposed.•The model's ability to predict the particle deposition distribution was validated.•The effects of slot setting, supply air angle, and temperature were investigated.

Enhanced soiling on the wall/ceiling around a diffuser due to particle deposition is very unsightly and reduces our quality of life. This study aimed to model the particle deposition on the surfaces around multi-slot diffusers, which are widely used in transportation vehicles. An SST k-ω model with a modified Lagrangian method was proposed and validated with experimental data on particle deposition rate from the literature. This investigation then conducted chamber tests to qualitatively validate model's ability to predict the deposition distribution around a multi-slot diffuser. Using the validated model, this study numerically investigated the effects of slot setting, supply air angle, and temperature differential on particle deposition around a multi-slot diffuser. The results indicated that, with the same supply airflow rate, increasing the area ratio of openings to bars in a multi-slot diffuser can reduce the particle deposition. When the angle between the supply air jet and the wall was increased to more than 45°, the particle deposition was significantly reduced. Furthermore, the impact of thermophoresis on particle deposition around a multi-slot diffuser was negligible.