Experimental investigation and numerical prediction of the performance of a cross-flow fan

Abstract

The concept of a fan-wing aircraft configuration for the purpose of vertical takeoff and landing has drawn much attention. Recently, more investigations revealed that a cross-flow fan (CFF) was capable of providing the propulsion. Several characteristics of the off-design performance of a CFF were experimentally measured, but insufficient numerical predictions were obtained. In the present study, the commercial CFD software ANSYS CFX was employed to calculate the unsteady flow through a CFF with a sliding mesh incorporated. The results of the CFD showed the necessity to re-investigate the cross-flow fan with 12-inch diameter, 1/5-inch span and 30 blades, and additional measurement locations were implemented to carry out a more accurate experiment. A new digital sensor array was used to record the pressures within the experiment, which contributed to the high fidelity of the present data. Successful comparisons wre made between the predicted and measured performance at various rotational speeds from an open throttle position to a setting at stall. Visualization of the computed flow field showed where stall occurred, both within the rotor and in the exhaust duct.