Whopping supersonic-car rocket rattles idyllic Cornwall
Boffin Jubb fires up Bloodhound's hybrid thruster
The Bloodhound SuperSonic Car team yesterday pushed the big red button on the "biggest rocket fired in the UK for over 20 years"*.
The Falcon Hybrid Rocket - a 45cm (18in) diameter by 3.6m (12ft) long unit burning hydroxyl-terminated polybutadiene solid fuel and high-test peroxide (HTP) oxidiser - roared to life for 10 seconds, producing 60kN (14,000lbf) of thrust.
The Bloodhound SSC rocket test
The test took place inside a hardened air shelter at the Aerohub, Newquay Cornwall Airport, which rattled as sound levels at the rocket nozzle peaked at 185dB, or "many times that of a Boeing 747 at take off", as the Bloodhound SSC announcement describes it.
The HTP oxidiser was pumped into the motor by a Cosworth CA2010 F1 engine at 600lbs per square inch, "equivalent to holding a large family car on the palm of your hand, and with enough flow to fill a bath in 5 seconds"**.
Motor designer Daniel Jubb - he of the magnificent handlebar 'tach - seemed satisfied with the smooth running of his baby. He told the BBC: "From what I could see, it looked very smooth indeed; and from the sound, there was not a lot of fluctuation - very steady."
Analysis of data from the test will determine if the hybrid's "unique star-shaped rubber fuel grain" did indeed burn evenly, although there's still a long way to go before the Falcon Hybrid Rocket can be bolted into the Bloodhound for an assault on the land speed record.
The ultimate planned power output of the motor is 111kN (25,000lbf) during a 20-second burn, peaking at 122kN (27,500lbf). This output, when combined with the thrust from the Bloodhound's Rolls Royce EJ200 jet engine, should ultimately propel the car to 1,000mph (1,600kph).
Artist's impression of the Bloodhound SSC thundering along
The team's first aim, though, is to hit 850mph (1,400kph), when pilot Andy Green takes the controls at the Hakskeen Pan dry lake bed in South Africa next year. ®
* In the 1980s, the Stonechat powerplants for the Falstaff research rocket produced 270kN (60,700lbf) during static tests.
** Readers are invited to calculate that flow in elephants per second.
F1 engine - check
Jet engine - check
Big rocket motor - check
Handlebar moustache - check
The only way this record attempt could be any cooler would be if the driver wore a tweed flat-cap and a pair of motorbike goggles.
Just ran the numbers.
I estimate that the flow rate was approximately 3.48 millielephants per second.
Working: 1 elephant = c. 4.598m^3
1 bath = c. 80l = 0.08m^3
1 bath in 5s = 0.016 m^3/s
Re: Massive testicles
Andy's nickname on the ThrustSSC project was Dead Dog. That was the sort of level of reaction that major emergencies elicited from him, probably because he was used to flying a Tornado ADV at high speeds and could cope with the workload.
Remember that ThrustSSC used rear-wheel steering and was not fully stable in yaw. Andy had to drive using a combination of fast and slow steering impulses to damp out the instability manually while doing all the other things such as monitoring speeds, engine parameters, brake parachutes, deal with overheating on-board computers and hope that the front of the vehicle didn't lift off the ground (there was an inverted ejection seat rocket motor to prevent this, fired by the on-board computer if it sensed the front wheel load drop below a certain threshold.
I watched him talking about the rocket motor test yesterday, he's the personification of calmness and was making a pretty good job of being a physics teacher too.
It's great to see what Britain's engineers and adventurers can achieve when put to the test. No other country has taken as many land speed records over the course of more than 120 years.