Development of a virtual test facility for axial flow cooling fans

Axial flow cooling fans are critical components in cooling systems for major industries like electricity generation, mineral processing and manufacturing. Efficient fans limit power consumption in these industries and consequently reduce operating costs. Due to their size, diameter sometimes exceeding 10 m, testing fans at full scale to estimate their performance is impractical. Traditionally, scaled down fan models are tested in compliance with testing standards, most notably ISO 5801. The test results are scaled up to the full-size fan using standard fan scaling laws. Physical testing can be time consuming and expensive, since physical models need to be manufactured and instrumentation installed, calibrated and maintained. This thesis attempts to simplify the performance prediction of axial flow cooling fans by developing a virtual test facility using computational fluid dynamics (CFD). Two analytical models, an inviscid Euler fan model and a blade element model (BEM), are developed to determine the significant parameters that drive fan performance and establish ideal fan efficiency limits. These models can be used in the preliminary stage of fan design or to estimate the realisable performance of an existing fan. A numerical model based on an ISO 5801 type A fan test facility is developed, verified and validated for a single reference fan using ANSYS® Fluent 2023 R2. The model is adapted to accommodate a range of axial flow cooling fan geometries, and the setup is automated using scripting. Results show that the numerical model can predict fan static pressure and fan static efficiency for different fans with an average error of ~10% compared to physical test data. It has a low computational cost and is easy to set up. The developed models are applied in a case study where two fans are designed with blades constrained by different manufacturing techniques, namely pultrusion and moulding. The combined use of the models in the design results in both fans achieving simulated fan static efficiencies of ~55% with no tip clearance and ~50% with tip clearance at the design point. The case study further shows that fans with pultruded blades can match the performance of fans with twisted blades at higher flow coefficients.

Grantor dc:publisher

Stellenbosch : Stellenbosch University

Year dc:date.issued

2026

Author dc:creator

• Steenkamp, Johannes Andries

Advisors dc:contributor.advisor

• Van der Spuy, Johan
• Reuter, Hanno

Language dc:language.iso

en

Repository record dc:identifier.uri

https://scholar.sun.ac.za/handle/10019.1/135813

OAI identifier oai:identifier

oai:scholar.sun.ac.za:10019.1/135813