Simulation and Verification of Wing-In-Ground Aero-Olfactory Effect for the Gas-Sensitive Rotorcrafts

This paper proposes a method to simulate odor diffusion process under the wing-in-ground aerodynamic olfactory effect for gas-sensitive rotorcrafts and verifies its correctness by experiments. When an aircraft is flying close to the ground, the flow characteristics will be affected by the ground, the induced drag and wake volocity will be changed, which is called the wing-in-ground effect. The diffusion of odor plume under the wing-in-ground effect is different from the normal conditions. In this paper, the wing-in-ground effect is simulated by the opposite flow of two mirrored wakes. This method converts the influence of ground on wake vortexes into that of mirrored wake vortexes. Inspired by the PIV (particle image velocimetry) principle, a simple and easy-to-operate device that can be realized in the offices is designed and built to verify the accuracy of the simulation. The Hu invariant moments are used to compare the envelope lines of odor-plumes images in the simulation and experiment, and the results are converted into a number indicating the similarity between them. The comparison results show that the simulation model of the wing-in-ground aerodynamic olfactory effect is basically the same as the experimental one, that is to say, the proposed model is a reliable method to simulate the odor diffusion process under the wing-in-ground effect of rotorcrafts.