Jet Reaction is thrust powered using an afterburning jet engine. This method of propulsion packaged in a superbly engineered vehicle will give Jet Reaction a clear advantage over its competitors. This advantage raises an interesting question, “why do so few other teams use thrust power when the governing body clearly allows it?” Well the answer to this is probably as follows. If we look at the speed record cars and boats, ever since the 1960’s to be the ‘absolute world’s fastest’ you have to use thrust power and because there is very little practical size limit on 4 wheels or boats they have mostly used ex jet fighter engines, however, this is an awkward and impractical option on a finely balanced two wheel machine. So to use thrust on two wheels you either need to scratch build a rocket system or substantially modify another type of gas turbine, neither is easy.
The engine in Jet Reaction is based on a 1250HP helicopter engine. However, this engine normally provides a shaft drive as opposed to thrust output. Richard has professionally redesigned and re-
An aerodynamic analysis
An aerodynamic analysis of Jet Reaction has recently been carried out by Huddersfield University in conjunction with Jet Reaction. The investigation and report was compiled by Taimoor Asim ands supervised by Professor Rakesh Mishra -
When designing a vehicle to travel at very high speed, although aerodynamic principles are incorporated at the initial concept, it is essential to verify the principles applied. The main aim of this report was to analyse the aerodynamic effect on Jet Reaction as it reaches its target speed of 425mph
The air around us that we take for granted is actually more dense and viscous than we realize, one cubic meter of air at sea level weighs around 1.25Kg. As a vehicle travels at high speed it has to punch a hole through the air which causes drag and turbulence as the air travels over the surface of the vehicle.
The ideal perfect shape would be as small and as clean as possible like a missile or torpedo, however a land speed vehicle such as Jet Reaction also has a cockpit canopy for the pilot, wheels, intake vents, jet exhaust and stabilizing fin.
These additions can cause further air turbulence creating high and low pressure areas, which not only cause drag but also can cause lift or down force or even both at the same time, causing the vehicle to be unstable.
With modern advances in computer aided design it is now possible to predict the aero forces using CFD (Computational Fluid Dynamics) This type of technology has now reached a level that will predict the aerodynamic behaviour of bodies moving at high speed with reasonable accuracy. It is not practical to present all the findings here but a glimpse of the report is contained in the images here.
Using the 3D CAD image of the vehicle a mesh is created around the vehicle to allow the computer to predict the aerodynamic forces.
Images such as this show the pressure & velocity changes around the vehicle. This excellent report has verified the design and allowed us to continue in the next phase of composite body construction. Jet Reaction would like to thank Taimoor Asim and his team at Huddersfield University for their valuable support.
Jet Reaction Gallery
Having developed the engine the next step is to package it and the driver into a safe but minimal frontal area, (Jet Reaction’s frontal area is as small as any of any current contenders) whilst still fulfilling all the other requirements such as correct position of wheels, brakes, (including parachutes) retractable stabilisers, air intakes, fuel tank, battery, etc. The finished design must of course be aerodynamically efficient with the centre of gravity in the correct position, many FIM safety rules also have to be adhered to, Jet Reaction meets all this criteria.
World Two Wheeled Land Speed Record Challenger
“An outright land speed record is one of the finest opportunities any team can have to demonstrate engineering innovation, within the rules applied by the relevant governing bodies the challenge is to engineer a superior machine making it the best in the world.”