BLOODHOUND car's rocket system to be tested
By David Szondy
October 1, 2012
On Wednesday, Britain’s BLOODHOUND team will take the next step in their attempt to break the land speed record when they test Europe’s largest hybrid rocket engine at the Aerohub, located at Newquay Cornwall Airport. The static test for the BLOODHOUND SSC car’s rocket system will be the largest rocket fired in Britain in 20 years and, if successful, will open the way toward building a car capable of doing 1,000 mph (Mach 1.4, 1,600 km/hr).
Meanwhile, the British Ministry of Defence announced today that the British Army's Royal Electrical and Mechanical Engineers (REME) has assigned a team of five REME engineers to assist the BLOODHOUND team in building and maintaining the rocket car over the next two years in the UK and during the record attempts at Hakskeen Pan, Northern Cape, South Africa.
Building a car that can blast along at almost one and a half times the speed of sound isn’t a simple task. It isn’t like taking a Mustang and swapping out the original engine for a bigger one. It requires a whole new powerplant with not one, but three engines to do the job. In this case, the BLOODHOUND is designed around a rocket engine designed by 28 year-old self- trained rocketeer Daniel Jubb.
It’s called the Falcon and at four meters (12 ft) long, 45.7 cm (18 in) in diameter and weighing 450 kilograms (992 lb), it isn’t a lightweight. When it’s finished, it will blast out a 25-foot (8 m) long tail of flame that advertises its approximately 27,500 pounds (122 kN) of thrust, which is about 80,000 bhp (60,000 kW) or the combined output of 95 Formula 1 cars.
The Falcon is one of three parts of the power plant that will shoot the BLOODHOUND along. It’s what’s known as a hybrid rocket. Normally, rockets come in one of two varieties. They either burn solid or liquid fuel. In the case of the Falcon, it burns both.
The reason for this is a matter of control. Solid rockets have been used in cars since the likes of Fritz von Opel first strapped them to cars in the 1920s. At first glance, they seem ideal, since a solid rocket motor is nothing but a tube packed with propellant. You simply bolt it on to the car, get in, light the fuse and off you go. The only problem is that solid rockets are an all-or-nothing affair. Once lit, there’s nothing you can do except hang on and wait for the fuel to burn up. They can’t be turned off and they can’t be throttled.
That’s where hybrid rockets are clever. The fuel used by the Falcon is hydroxyl-terminated polybutadiene. That sounds impressive, but it’s just another name for synthetic rubber. Impregnated with metal powder and an oxidizer, it’s a very good rocket fuel and has been used in Polaris and Trident Missiles for over half a century. Where the Falcon’s rocket motor differs is that the fuel has no oxidizer in it. If you light it, it just smolders and makes an awful stink like burning tires.
The hybrid part comes in with the oxidizer. The Falcon uses an extremely concentrated form of hydrogen peroxide, which is pumped over a silver-plated catalyst. This breaks down the peroxide into steam, oxygen and heat. The steam superheats and ignites the fuel and the oxygen causes it to burn at 3,000ºC (5,400ºF). The result is lots and lots of thrust. However, unlike conventional solid rockets, you can throttle down or even shut the motor off by controlling the feed of peroxide to it.
So far so good, but the Falcon motor is a thirsty beast and needs 963 kilograms (2,123 lb) of peroxide in under 20 seconds. To deliver this, the BLOODHOUND is equipped with a pump from an Avro Blue Steel stand-off nuclear missile from the 1960s. This is powered by a V8 CA2010 Formula 1 engine putting out 750 bhp (559 kW). Connected to the pump by a custom gearbox, it can fill a domestic bath in less than five seconds, so there’s a practical application to the technology.
The third part of the power plant is an EJ200 jet engine from a Typhoon fighter plane. Its job is to run the BLOODHOUND for the first 25 seconds of the run while it speeds up to 350 mph (563 km/hr). At that point, Royal Air Force pilot Wing Commander Andy Green, who will drive BLOODHOUND, presses the trigger and is flattened against his seat by 2.5 Gs as BLOODHOUND breaks the sound barrier.
Wednesday’s test won’t have BLOODHOUND going anywhere, nor will the EJ200 jet engine be involved. It’s a static test to evaluate the rocket system. It will be conducted inside a hardened shelter with images and data fed to engineers, guests and the media in another building. The public will be able to follow the test by live streaming feed. The test will last about ten seconds, generate 30,000 bhp (22 370 kW) and create enough noise to make a 747 on takeoff sound like a whisper.
If the static test is successful, runway tests will be conducted in the UK in 2013. Later and into 2014, the team will make their record attempt in South Africa.
The video below is an animation showing the BLOODHOUND's rocket system in action.