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 to study or re-think stall control solutions. In tunnel and metro fans this means to study how anti-stall rings work and to provide strategy to improve their efficiency. 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 synthetize the effects of the anti-stall ring with an actuator disk, strongly reducing the computational load required and validating a new 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.