Modelling of Axial Fan and Anti-Stall Ring on a Virtual Test Rig for Air Performance Evaluation

Market requests for higher performance fans and legal requirements to meet minimum efficiency grades drive industrial fan designers for tunnel and metro applications to study or re-think stall control solutions. This paper, therefore, focuses on how anti-stall rings work and provides a robust and fast numerical methodology to evaluate and improve their efficiency and effectiveness. Here we present a numerical study validated against available experiments on the fitting of an anti-stall ring on an axial fan for tunnel and metro operations. The study synthetizes the effects of the anti-stall ring with an actuator disk coupled to a frozen rotor model for the fan, significantly reducing the computational load required and validating the methodology. Such approach can be implemented to easily derive fan performance with different geometries of the anti-stall ring plenum as well as its fins.