Computational Fluid Dynamics Simulations of Aerodynamic Performance of Low-Pressure Axial Fans with Upstream Blockage
Paper in proceeding, 2024

Rotor-only ducted low-pressure axial fans play a crucial role in automotive thermal management of the tightly packed under-hood region. Most current scientific work concerning low-pressure axial fans investigate the aerodynamic performance of these fans while operating with uniform inlet flow conditions. This is rarely the case in real-world applications. This work aims to investigate the aerodynamic performance of low-pressure axial fans operating with upstream blockages. First, a validation study is performed in the absence of any upstream blockage. Numerical results are compared against publicly available experimental data. Steady-state, Reynolds-Averaged Navier Stokes (RANS) analysis is performed on a single-blade passage. The validation study also evaluates the choice of turbulence model and suggests the use of the k- ε turbulence model with wall functions for the best comparison against experimental data. To study the effect of upstream blockage, a generic blockage disc is positioned upstream of the fan inlet. Three different radial extents of the blockage disc is evaluated, such that different radial extents of the blade span is blocked. A strong influence of the upstream blockage is observed on the fan performance and flow distribution along the blade span. The total-to-static pressure coefficient and the total-to-static efficiency decrease proportionately to the extent of blockage in the radial direction. The peak total-to-static efficiency moves to a lower flow coefficient with increase in upstream flow blockage. This is deemed undesirable for automotive applications where it is desirable to have maximum aerodynamic efficiency at the highest possible flow coefficient.


Upstream Blockage


Thermal Management

Single Blade Passage Analysis


Debarshee Ghosh

Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics

Niklas Andersson

Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics

Sassan Etemad

Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics

SAE Technical Papers

01487191 (ISSN) 26883627 (eISSN)

2024 SAE World Congress Experience, WCX 2024
Detroit, USA,

Subject Categories

Energy Engineering

Vehicle Engineering

Fluid Mechanics and Acoustics



More information

Latest update