Aerodynamic Characterization of a Fan Array Wind Generator

TL;DR

This paper provides a detailed aerodynamic analysis of a fan array wind generator, revealing flow characteristics and limitations crucial for UAV flight control under gusty conditions.

Contribution

It offers the first comprehensive experimental characterization of a small fan array wind generator's flow dynamics, informing future improvements and control strategies.

Findings

Flow has a jet-like core with uniform velocity

Flow contracts and shear layers grow unsteadily downstream

Limited region with desired flow profile and turbulence

Abstract

Experimental assessment of safe and precise flight control algorithms for unmanned aerial vehicles (UAVs) under gusty wind conditions requires the capability to generate a large range of velocity profiles. In this study, we employ a small fan array wind generator which can generate flows with large spatial and temporal variability. We perform a thorough aerodynamic characterization operating the fans uniformly from a low to the maximum level. PIV and hot-wire measurements indicate a jet-like flow with nearly uniform core which monotonously contracts in streamwise direction and surrounding growing unsteady shear-layers. These complex dynamics results in a limited region with desired flow profile and turbulence level. The experimental results shed light on the flow generated by a full-scale fan array wind generator, and indicate the need for further improvements via properly designed add-ons and dedicated control algorithms.