Numerical simulation and geometric optimization on active chilled beam to improve airflow uniformity

To enhance the comfort of active chilled beam (ACB) air conditioning systems, this study employs numerical simulations and geometric optimization of the ACB terminal unit to improve airflow uniformity at bilateral nozzle outlets. A computational fluid dynamics (CFD) model was developed for a unidirectional side air supply ACB (dimensions: 660 mm × 540 mm × 162 mm) to systematically investigate flow dynamics. An innovative geometric configuration was proposed, integrating an arc baffle within the plenum chamber to optimize airflow distribution. Key structural parameters were systematically evaluated under consistent operational conditions to identify the optimal design. A comprehensive parametric analysis further examined the effects of primary air pressure variations (60, 110, 160 Pa) and nozzle contraction angles (6°, 8°, 14°) on flow uniformity. Results demonstrate that baffle integration significantly improves airflow homogeneity, with arc baffle exhibiting superior performance compared to rectangular baffle. Additionally, to ensure practical feasibility, we investigated the impact of the arc baffle structure on the induction ratio. The optimized configuration achieves induction ratios under primary air pressure variations (60, 110, 160 Pa) that all fall within the practical application range. This design balances airflow uniformity and thermal performance, ensures adequate cooling capacity, and verifies its practical feasibility.