We built a car
Staff and students at the University have built a full size rocket-powered car. The Vauxhall VX220 sports car, was fitted with a large hybrid rocket motor that is designed to produce over half a tonne of thrust.
Since the car weighs about the same, it should be capable of accelerating from 0 to 60mph in about 3 seconds - better than almost any car on the road. Top speed, however, is not much more than 60mph, for reasons of safety and due to limits on the amount of propellant stored.
All of this was achieved in only 6 weeks from being given the go-ahead, and the car had its first outing on Tuesday 28 February 2012. The runs were filmed and form part of an article about the Bloodhound supersonic car in the BBC1 programme Bang Goes the Theory, broadcast on 30 April 2012.
Although the full performance goals were not achieved, the car did complete 2 runs with the ignition system working as intended first time for both runs.
- Car: Vauxhall VX220 - lightweight sports car with fibreglass shell on aluminium alloy chassis. Engine, gearbox and other unwanted items removed. All-up weight under 600kg
- Rocket motor: hybrid rocket motor, using polypropylene fuel grains and nitrous oxide oxidiser. Approx 10kg nitrous oxide per run, in 4 cylinders, producing 600kg thrust. Motor is 2m long and 150mm diameter
- Ignition: staged ignition using oxygen and a pyrotechnic igniter, then switched over to nitrous oxide for idling. Throttle pedal used to control main thrust (variable)
- Performance (predicted): 0 - 60mph in 3 seconds, or 1g acceleration
- Braking: standard brakes without servo assistance, plus 3-metre brake parachute deployed by an explosive charge.
The project brought together undergraduate final-year projects to design the rocket motor and the feed and control system with inputs from staff and volunteer students. It is also a nice blend of aerospace and automotive technologies.
The design had been progressing as a theoretical project until January 2012, when the go-ahead was given to build it for real. The deadline was the end of February for the first test-run.
The task turned out to be a little bigger than most of the team expected, mainly due to additional measures to ensure driver safety, over those originally thought to be adequate. Thanks are due for the advice received from technical experts and Health and Safety personnel across 2 organisations.
The original budget was almost adequate, but a great deal of financial assistance was received from a range of sponsors that made the build possible. In the end, the total cost, excluding the car itself, was around £8000.
- Safety Devices - roll cage
- Blended Products/Nitrous Oxide Supplies - nitrous oxide cylinders
- Corbeau - seat and harness
- Fire Extinguisher Valve Co - fire extinguisher
- RCS Cable Division of RINGSPANN - control cables
- Rockets and Things - parachute
- Herts Signs - fixing signage
- Hydravalve - valves
- Wizards of NOS - solenoid valves
See the car being built
Pictures of the build
The driver being strapped in to adjust belts. With a 6-point harness and a
wrap-around racing seat, it's very snug in there. The easiest way out is straight
up through the roll cage.
Final adjustments being made to the motor controls, before buttoning
up for the first run. A dual-redundant valve system protects against
failures and a valve freezing.
Electrical controls for the car. Blue is oxygen, red is idle, with
a big, black Start button in the middle. The switch to the right
of those is the parachute arming switch to protect against
premature deployment when preparing for the run, with the
Master switch below it. There's no stereo...