A Design Framework for Subsonic Low-Speed Wind Tunnels

Wind tunnels can be used to perceive the aerodynamic behaviour around objects by sending streamlined air at suitable speeds. This paper entails the details of work focusing on building a design framework for subsonic low-speed (wind speeds less than a Mach number of 0.3) wind tunnels with a medium-scale test section, which reduces the mathematical modelling and analysis required in designing a wind tunnel from scratch, and in turn, reduces the cost. The approach to building the design framework is based on non-dimensional parameters of the component geometry. In order to obtain the most optimum non-dimensional parameters for each critical component (mainly contraction and diffuser), a computational fluid dynamics (CFD) analysis followed by a MOGA (Multi-Objective Genetic Algorithm) design optimization is performed using the ANSYS software package. A combined model of contraction, test section and diffuser is optimized using ANSYS DesignXplorer, governed by objectives set for an optimum flow condition in the test section. In the optimization process, flow simulations are done through ANSYS FLUENT. Using the resulting optimum non-dimensional parameters, a database is developed for different test section dimensions in the medium-scale range. The database is then fed into an online platform (https://blk-vol1-2f260.web.app/) where users can obtain complete design specifications for the wind tunnel by entering the required wind speed and test section dimensions.