Paper Title
EFFECT OF DIFFUSER ON AXIAL JET FAN’S PERFORMANCE FOR CAR PARKING VENTILATION

Abstract
This study analyzes the effect of the diffuser on the flow performance of the axial jet fan for car parking ventilation. Efficient ventilation is essential in enclosed car parking to remove hazardous gases such as carbon monoxide and maintain safe air quality. The axial jet fan geometry, including the inlet nozzle, rotating fan blades, casing, and outlet diffuser, was created based on design specifications. The investigation considers three configurations: an axial jet fan without a diffuser, and with a diffuser angle of 5° and 10° respectively, and evaluated using computational fluid dynamics (CFD) simulations in ANSYS CFX. Velocity, total pressure distribution, pressure recovery coefficient and diffuser efficiency are evaluated by numerical simulations. Results show that the axial jet fan with a diffuser angle of 5° was found to be the best design development having better pressure recovery and efficiency than the two others. Diffuser angle is a key design parameter effecting pressure recovery and aerodynamic performance of axial jet fans for car parking ventilation. Keywords - Axial Jet Fan, Car Parking Ventilation, Computational Fluid Dynamics (CFD), Diffuser, Numerical Analysis.