Rubens Tube and Hybrid Rocket Engine

A Rubens tube is an eye-catching demonstration of standing waves in gasses. Propane gas is fed into a long metal tube with many small holes drilled in the top, from which flames emerge. A transducer (loudspeaker) at one end feeds an audio signal or music into the tube which modulates the pressure, changing the height of the gas flames and visualizing the standing waves. If time allows, a keyboard will be made available for spectators to play music into the tube, allowing interaction with the installation. The Rubens tube will be run multiple times per evening, and possibly during the day, depending on propane stocks and weather conditions.

In line with the space theme of the event, we're also bringing a small hybrid rocket engine. This runs on oxygen gas and uses a solid acrylic fuel grain and has been demonstrated previously at EMF 2018 (talk: "It's only rocket science") and Wuthering Bytes. This will be run once or twice per evening for around 20 seconds per firing. It will be located on the same site as the Rubens tube but the two will not be run at the same time.