Optimizing Wheel Fairings for Fixed Gear Aircraft

Abstract

Fixed landing gear on aircraft inevitably increases drag and lowers aerodynamic efficiency. The use of wheel fairings in general aviation decreases drag, however, few studies have examined the optimization of fairing design. The current study begins to address the question of the aerodynamic effects of different designs of the wheel fairing’s trailing edge. Wheel fairing models were created using Solidworks 2021 and 3d printed. The height of the trailing edge (percent of maximum fairing height, % height) was altered based on modern widely used fairing designs. Models were tested in a water channel and a small-scale wind tunnel. Force sensing and particle image velocimetry (PIV) were conducted to determine an improved design of the fairing’s trailing edge and the resulting aerodynamic effects. Time averaged chordwise flow separation and the resulting velocity deficit were analyzed along with the drag force. Housing the wheel inside a fairing dramatically decreased vorticity (a measure of rotation in a fluid), increased the wake velocity, while decreasing the drag force. Compared to a 30% height fairing, the 0% height fairing (pointed trailing edge) created a broader area of elevated vorticity and velocity deficits in its wake in the water channel. It also resulted in a larger drag force as assessed in the wind tunnel. This study highlights that altering design of the trailing edge by increasing its height from 0% height to a broader profile can improve efficiency of fairings.