Students lightbulb moment helps capture stunning images at supersonic speeds
A Leicester Engineering student has taken his handyman skills to a new level by repairing a piece of legacy teaching equipment using materials sourced at his local DIY store.
When the Gas Dynamics laboratory in the Department of Engineering found replacements for a new schlieren light source to be rather pricey, third-year project student Ryan Williams used his own initiative to fabricate a new light source from an electronic light he bought for just a few pounds from a nearby DIY store.
The light source was used with the lab’s Plint supersonic wind tunnel, a teaching tool used to support the delivery of the compressible flows curriculum. Its working principle is very similar to that of the common paint spray gun, or that of an old carburettor in a car: fast air is ejected downstream of the test section and this induces a fast flow through the upstream test section.
The test section in the tunnel is very small, measuring just one inch across, and placing intrusive measurement techniques in such a confined space is virtually impossible. Instead, students need to use optical, non-intrusive, measurement techniques requiring a compact light source.
Ryan put together an economical option in the form of a light source of very compact size, which is important for visualising shocks and expansion fans.
In December, Ryan managed a good run from the Plint tunnel, ‘going supersonic’ at Mach 1.8, capturing the images to the right. These images are possibly the best quality acquired to date from the single-pass schlieren configuration in the Plint tunnel. These images will be used to update the compressible flows section of next year’s EG3102 Thermodynamics and Fluid Dynamics 2 module.
The Plint wind tunnel was rebuilt by another third-year student, Milan Dodia, in 2011 after the components had lain in storage for several years.
Thanks are also due to Dipak Raval and to Paul Williams, who lent Ryan his personal SLR camera.