Rocket car on course for 1609km/h run

Published Jul 18, 2014

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Bristol, England - It’s so powerful that it will use a 480kW racing engine just as a fuel pump. The real grunt comes from a jet engine and a rocket engine whose combined thrust is equivalent to about 180 Formula One cars.

That’s the kind of power needed to propel the Bloodhound supersonic car faster than a speeding bullet, to a new world land speed record of 1609km/h (1000 miles per hour in the old pre-metric parlance) at South Africa’s Hakskeen Pan in 2016.

The 13-metre, seven-ton machine will use its Rolls-Royce EJ200 fighter jet engine to accelerate to 480km/h, whereafter a hybrid rocket designed by Nammo will boost the car the rest of the way.

The arrow-shaped car has been slowly taking shape in Bristol, where it is scheduled to undertake its first “low-speed” test (about 320km/h) in mid-2015 before heading to Northern Cape’s Hakskeen pan later in the year with the target of reaching 1287km/h. The team will go home to review the data and return to South Africa in 2016 with the aim of reaching 1609km/h on a 19km cleared section of the pan.

The ambitious project is being run by speed kings Richard Noble and Andy Green who between them have held the land-speed record for 31 years.

Richard Noble - engineer, adventurer and former paint salesman - recorded 1019km/h in the jet-powered Thrust2 in the Nevada desert in 1983. In 1997, he headed the project to build the ThrustSSC but handed the driving reins to British air force pilot Andy Green, who reached 1228km/h and became the first driver to break the sound barrier in a land vehicle.

Wing Commander Green will again be at the wheel when Bloodhound SSC, if all goes to plan, cover 19.3km in just two minutes during its 1609km/h record attempt at Hakskeen Pan.

Apart from strapping a rocket to a missile-shaped chassis there’s a lot of painstaking detail involved in making a car go this fast, which is why the six-year-old project has been delayed from its original objective of making the record attempt in 2013.

HAND-CRAFTED

For instance, it’s taken more than 10 000 hours just to design and build the monocoque cockpit, which was hand-crafted using five different types of carbon fibre to weave three different thicknesses of aluminium honeycomb. The driver will be protected by a windshield that can withstand an impact with a 1kg bird at 1448km/h.

Also tricky was getting the aerodynamics right in a vehicle that at its top speed will take just 2.25 seconds to cover each kilometre, which is why it was designed using Computational Fluid Dynamics to provide an understanding of the aerodynamic characteristics.

If supersonic air reaches the jet engine fan blades, the airflow will break down and the engine will choke (known as a surge). This can generate huge changes in pressure that could damage both the jet engine and car, so the Bloodhound SSC will use shock waves over the canopy to slow the airflow from more than 1609km/h to just 643km/h in a distance of about one metre.

Deflecting winds travelling five times faster than a hurricane will, however, be rather noisy.

Below 1207km/h (at which point the car will outrun its own sound waves), the shock wave and jet intake noise levels are expected to produce over 120 decibels inside the cockpit, which is as loud as a thunderbolt.

Solid aluminium wheels are used because rubber tyres would be torn off the rims at speeds of more than 600km/h.

Deceleration is really “where the fun begins”, says Noble, and it requires a combination process: first, Green must close the throttle, which causes an initial 3g deceleration, reducing the car’s speed from 1600 to about 1290km/h, upon which airbrakes are deployed.

The first braking parachute is deployed below 965km/h, followed by a second parachute (if required) below 644km/h.

Only at around 400km/h can Green press the brake pedal (anything over that and the discs would ignite) to bring the high-speed contraption to a halt. If all goes according to plan, the car will be stopped in 7.2km (of the available 8.8km), the same distance it took to reach its top speed.

The vehicle is then ready to be turned around for the second leg of the run, which it must complete within an hour with the average speed of the two runs taken to be counted as a record. - Star Motoring

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