Profile vortex shedding from low-speed axial fan rotor blades: a modelling overview

This paper presents an overview of the characteristics potentially influencing the profile vortex shedding (PVS) phenomenon being relevant in noise and vibration of low-speed axial fan rotor blades. Dimensional analysis has been applied to explore the essential dimensionless quantities in a systematic and comprehensive manner. On this basis, limitations have been established, and simplifying assumptions have been set up in terms of PVS investigation. Groups of dimensionless characteristics playing a role in the semi-empirical model for predicting the PVS frequency were identified. The available semi-empirical model and its unique features related to the measurement evaluation methodology and Reynolds number dependence have been outlined. The presented comprehensive analysis provides guidelines from the perspective of transferability of the literature data on PVS from steady, isolated blade profile models to low-speed axial fan rotors. It also results in the formulation of objectives of future research related to PVS.