Wind Tunnel Design Basics-Subsonic Wind Tunnels (Contd); Supersonic Wind Tunnels- Introduction — Lesson 3

This lesson covers the internal design issues related to subsonic wind tunnels and initiates a discussion on supersonic wind tunnels. It explains the section loss coefficient and the energy ratio of the tunnel, using a numerical simulation of a typical closed circuit wind tunnel. The lesson also provides an in-depth understanding of how the static pressure varies along the tunnel circuit and the optimum running conditions for the fan. It concludes with a brief overview of an intermittent blow down supersonic wind tunnel. For instance, the lesson explains how a fan can operate at different RPMs and how this affects the fan's characteristics and the tunnel's operation.

Video Highlights

01:32 - Demonstration of a numerical simulation for a typical closed circuit wind tunnel.
05:44 - Calculation of the section loss coefficient for a diffuser experimentally.
22:42 - Explanation of the optimum running conditions for the fan in a wind tunnel.
28:33 - Introduction to the supersonic wind tunnels and their structure.

Key Takeaways

- The section loss coefficient and energy ratio are crucial aspects of wind tunnel design.
- The static pressure varies along the tunnel circuit, and understanding this variation is essential for efficient tunnel operation.
- The fan's RPM significantly affects the fan's characteristics and the tunnel's operation.
- An intermittent blow down supersonic wind tunnel has a unique layout that includes a compressor, a dryer, a storage tank, a gate valve, a pressure regulator, a settling chamber, a CD nozzle, a constant area test section, and a supersonic diffuser.
- The heart of the supersonic wind tunnel is its test section, where models are mounted for pressure measurements and other analyses.