Effect of a Gurney Flap on the Performance of an Axial Fan

Abstract

5The Gurney flap (GF) is a miniature lift-enhancement device and is usually mounted at the trailing 6 edge of an airfoil. The GF and has been successfully applied to isolated airfoils, multi-element 7 airfoils, and aircraft wings as well as helicopter rotor due to its attractive features of simplicity, cost-8 effective and separation control. The GF also has aroused the attention of researchers in the 9 turbomachinery industry. However, limited studies are currently available on the application of a 10 GF to an axial fan. 11Hence, in this paper, we conduct a wind tunnel and computational fluid dynamic (CFD) 12 investigation on an axial fan profiled with a NACA 65-(12)10 airfoil to evaluate the effect of the GF 13 on the performance of the fan. We also present the detailed flow features of the fan with and 14 without the GF after validating the simulation results with the experimental results. The 15 experimental results show that as the GF is installed higher on the fan blade, it can produce a higher 16 total pressure rise accompanied with a greater loss of efficiency. The installation of the GF also 17 enlarges the work capacity of the fan. Detailed flow field analysis, including the surface pressure 18 distribution, vorticity distribution at the trailing edge and streamline distribution of the fan, is 19 carried out to understand the mechanisms of the effect of the GF on the performance of the fan. 20

Simulation of the Influence of Wing Angle Blades on the Performance of Counter-Rotating Axial Fan

“…Among them, factor A was the position s1 of first-stage blade tip, factor B was the tip offset distance a1 of first-stage blade, factor C was the position s2 of second-stage blade tip, and factor D was the tip offset distance a2 of second-stage blade. According to relevant fan studies, the main work area of the blade was the upper middle part of the blade, and the maximum static pressure coefficient was the largest at the pressure front edge at 75% of the blade height [16]. Therefore, the position s of the wing Angle was selected in this area.…”

“…The prototype blades and wing angle blades are, respectively, analyzed at 25%, 50% and 75% relative blade heights. The relative position R = x/L is defined, where x is the distance from any point on the blade to the leading edge of the blade [16], and L is the chord length of the blade, mm. To the left of the black dotted line is the leading edge of the blade.…”