CFD Analysis of Automotive Air Vents and Exploration of a Coandă-Based Conceptual Design

The optimization of automotive HVAC (Heating, Ventilation, and Air Conditioning) vents has become crucial, as it affects passenger comfort, both thermal and acoustic, while also influencing system efficiency and ensuring seamless integration within the cockpit, where perceived quality is assuming an increasingly central role. In recent years, the pursuit of highly integrated or even “invisible” outlets has therefore emerged as a fundamental design objective, combining functional performance with stylistic coherence. This thesis investigates vent performance through two phases: the computational fluid dynamics (CFD) analysis of production configurations and the development of an innovative concept inspired by the Coandă effect. In the first phase, CAD geometries of production driver-side vents were supplied through company collaboration, simplified and prepared for CFD simulations in ANSYS Fluent. A systematic workflow was established, covering pre-processing, mesh sensitivity analysis, solver setup and post-processing. Indicators such as pressure drop and outlet velocity distribution were evaluated for different vane orientations. Results confirmed the strong influence of duct geometry on pressure losses and showed how vane angle governs the velocity field and the airflow perceived by the occupant. The second phase examined a novel vent concept based on the Coandă effect, a phenomenon in which a jet attaches to a curved surface, also exploited in fluidic devices for flow control without moving parts. A confidential design study was carried out in ANSYS Discovery, showing that the effect can be reliably reproduced and tuned by geometric parameters. Results demonstrated the potential to achieve a wide flow deflection range without moving mechanical elements, combining functional flexibility with improved design integration. Overall, the research establishes a robust CFD methodology for HVAC vent analysis and introduces a new design paradigm reconciling efficiency, comfort and aesthetics, paving the way for integrated vents in next-generation HVAC systems.