In 1997, FlowMotion successfully designed its first axial impeller. The development methods employed at the time were ‘state of the art’. Much has changed since then. The introduction of CFD (Computational Fluid Dynamics) enables the analysis of local flow along the impeller blades, providing precise information regarding blade aerodynamics. FlowMotion has been successfully offering CFD services, as well as the associated analyses and developments, to the fan industry for many years.
In the past, it was essential to generate a computational grid for CFD investigations that met the highest aerodynamic and numerical standards. The computational grid has a significant influence on the accuracy of the flow simulation in the immediate vicinity of the blade (boundary layer). The grid cells along the surface of the blade must maintain a specific distance from the surface, which can be described by the y+ value.
A great deal of development work was invested in generating a computational grid that satisfies the theoretical requirements for the y+ value. This applies in particular to the gap area between the blade and the housing, as well as the leading and trailing edges of the blade. Comparison of the CFD calculations with measurements using this computational grid shows very good agreement over a wide pressure range.
This new development method can provide FlowMotion with an even deeper insight into the aerodynamics of axial impellers, enabling us to continue offering the best fans in the future.
