Experimental study of blade thickness effects on the global and the local performances of axial-flow fans

Christophe Sarraf (1) , Florent Ravelet (1) , Hussain Nouri (1) , Farid Bakir (1)

1 DynFluid - Laboratoire de Dynamique des Fluides

The study of Aerodynamic performance of axial-flow fans was carried out. Two fans that differ only in the thickness of their blades were studied. The first fan (Fref), which is the reference, was designed to be part of the cooling system of an automotive vehicle power unit and has conventional thin blades. The second fan (Ftck) has much thicker blades compatible with the rotomoulding conception process that generates only hollow parts with large edge radius. The global performances of the fans were measured in a test bench designed according to the ISO-5801 standard. The curve of aerodynamics characteristics (pressure head versus flow rate) is slightly steeper for the fan with thick blades, and its efficiency is lower than the efficiency of the fan with thin blades. To go further in the comparison, we also studied the wall pressure fluctuations at the casing wall in another normalized test bench, for two flow rates corresponding to the maximum efficiencies of the two fans. The total level of fluctuations is lower for the thick blades fan that for the thin blades fan, which is counter-intuitive. The spectral composition of the wall fluctuations are moreover very different for the two fans. These measurements will be used as a benchmark for high-order finite volume CFD codes developed for aeroacoustics in the laboratory.

Mots clés: Axial flow fans; turbomachinery; pressure fluctuations; rotomoulding

Domaines: Dynamique des Fluides [physics.flu-dyn]

Christophe Sarraf, Florent Ravelet, Hussain Nouri, Farid Bakir. Experimental study of blade thickness effects on the global and the local performances of axial-flow fans. 7th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Jul 2010, Antalya, Turkey. pp.1428. ⟨hal-00453101⟩