Design, Fabrication and Performance Evaluation of Low Speed Open Jet Wind Tunnel for Free Flight Testing

Abstract

With the development in the field of aerodynamics, a test model of aircraft, UAVs, MAVs and other flying and moving vehicles need to go under rigorous test in wind tunnel for stability, lift, drag and other aerodynamic parameters. Despite of development of CFD for flow simulation over a body, experimental setup with proper f low conditions is necessary for carrying out actual aerodynamics test. This paper presents conceptual design, numerical simulation and experimental setup of low speed open jet wind tunnel of blower type having a rectangular test section of 1.5 m in width and 0.8 m in height. The developed wind tunnel uses multiple fans arranged in array as drive system to produce airflow in the wind tunnel. The basic frame of experimental setup was made using plywood. Performance evaluation was done through flow field evaluation creating sample points and measuring f low velocity at different fan speed using anemometer. The characterization of the wind tunnel was carried out at flow velocity of 6.5 m/s. The performance evaluation showed that the mean flow uniformity lies in the range of ±5% compared to average velocity. For application of the developed wind tunnel, the aerodynamic loading on wing made up of balsa and fiberglass was observed. Similarly, control surface response test of 0.6 times scaled model of Skywalker X8 was performed in the developed open jet wind tunnel. This type of open jet wind tunnel can widely be used for verifying simulations, simulating flight conditions and obtaining experimental data for aerodynamic forces and free flight tests.