The Bloodhound SSC team has unveiled the cockpit of its 1,000mph land speed record car.
The carbon fibre monocoque has been tailored to the needs of driver Andy Green, who has drawn on his experience of flying fast jets and driving World Land Speed Record winners Thrust SSC and JCB Dieselmax to design the layout.
The cockpit will be his supersonic office during record attempts in the South African desert during 2015 and 2016. Good ergonomics are vital given that Bloodhound SSC will cover a mile in 3.6 seconds, or 150m in the (300 millisecond) blink of an eye.
Hand crafted by URT Group using five different types of carbon fibre weave and two different resins, the monocoque has taken more than 10,000 hours to design and manufacture. Sandwiched between the layers of carbon fibre are three different thicknesses of aluminium honeycomb core (8, 12 and 20mm), which provide additional strength. At its thickest point the monocoque comprises of thirteen individual layers but is just 25mm in cross section.
The structure weighs 200kg and bolts directly to the metallic rear chassis carrying the jet, rocket and racing car engine. The carbon front section will have to endure peak aerodynamic loads of up to three tonnes per square metre, as well the considerable forces generated by the front wheels and suspension. It will also carry ballistic armour to protect the driver should a stone be thrown up by the front wheels at very high speeds.
The roof of the cockpit has been designed to create a series of shockwaves that will channel the air into the Eurojet EJ200 jet engine. 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. The shockwaves will slow the airflow from over 1,000mph (1,609km/h) to just 600mph (643km/h) in a distance of around one metre. Deflecting winds travelling five times faster than a hurricane will, however, cause additional noise and vibration to be transmitted into the cockpit.
The sound levels expected in and around Bloodhound SSC are being carefully evaluated. The cockpit is positioned in front of three incredibly loud motors: the jet, a cluster of hybrid rockets and the racing car engine that drives the rocket’s oxidiser pump. Collectively they will generate a noise level estimated at 140 decibels. Much of the noise will be directed backwards, away from the driver, and above 750mph (1,207km/h) the car will out-run its own sound waves. However, the project’s engineers still anticipate that shockwave and jet intake noise levels may produce over 120 decibels inside the cockpit. Andy will wear an in-ear communications system to protect his hearing and to ensure that he can communicate with Mission Control.
Bloodhound has a highly specialised windscreen custom-made by PPA Group from acrylic. The plastic is heated, stretched and then two layers are bonded together to create a 25mm section, thicker than a fighter jet’s windscreen and sufficient to withstand an impact with a 1kg bird at 900mph (1,448km/h). Due to the oblique angle the windscreen is set at, the driver will in fact be looking through 50mm of curved plastic. The key challenge has therefore been to make the screen robust while maintaining absolute visual clarity.
For more information on the Bloodhound SSC project, you can visit it’s website at www.bloodhoundssc.com