Fan performance characteristic tests of axial flow fans provide information on the global flow field, based on stable inlet flow field distribution. More information is often required on the local flow distribution existing in the vicinity of the fan blades under installed conditions. A 1.542 m diameter scale model of an axial flow fan, termed the M-Fan is tested in an ISO 5801, type A, test facility. The M-fan was specifically designed for low-pressure, high flow rate application in air-cooled or hybrid condensers. The scaled version of the M-fan was designed to have a fan static pressure rise of 116.7 Pa at a flow rate of 14.2 m3/s.
Two specially constructed M-Fan blades are manufactured to conduct blade surface pressure measurements on the blades. The fan blades are equipped with 2 mm diameter tubes that run down the length of the fan blades in order to convey the measured pressure. Piezo-resistive pressure transducers, located on the hub of the fan, measure the static pressure distribution on the blades and the data is transferred to a stationary computer using a wireless telemetry setup. The blade pressure measurement setup is re-commissioned from a previous research project and its performance is qualified by testing and comparing to experimental results obtained on the B2a-fan. Excellent correlation to previous results is obtained.
The experimental M-fan results are compared against results from a periodic numerical CFD model of a fan blade modelled in an ISO 5801, Type A test facility configuration. The experimental tests and numerical model correlate well with each other. The experimental blade surface pressure measurements have a minimum Pearson correlation to the numerically determined values of 0.932 (maximum 0.971).