Tag Archives | Dynamic Trimmers

…It’s Tuner Tuesday: Bloodhound SSC?

Bloodhound SSC

The Bloodhound SSC is more rocket than car, and aims to shatter the current world land speed record with a goal of 1,000 mph, or 31% faster than any four-wheeled vehicle has gone before.

Powering the Bloodhound SSC is a jet/hybrid rocket mix that uses a rocket for its raw power and a lack of draggy air intake, and a Eurojet EJ-200 jet engine for controlled output that allows the Bloodhound SSC team to increase Mach numbers in small, careful steps.

In addition to power, the Bloodhound SSC needs to be controllable, so little winglets above each wheel act as fully dynamic trimmers that make small adjustments in microsconds to maintain constant wheel load up to Mach 1.4.

Bloodhound SSC Detail

In the middle of the Bloodhound SSC sits a MCT V12 race engine that makes over 800 horsepower. This might sound like an impressive figure, but when you’re goal is 1,000 mph, it’s not even close to what you need, so the V12 is just there for hydraulic power, starting the EJ-200, and pumping more than a ton of High Test Peroxide through the Falcon rocket in just 22 seconds at 1200 psi.

Another important element of a car like this that few people think about is the airflow. The fin needs to be a balance of high speed stability and low speed wind resistance, and even the rear wheel covers have been designed to minimize drag caused by the airflow around the wheel, since an unprotected wheel would see oncoming airflow at the top reach speeds of Mach 2.8 if left unprotected.

So what does a run to 1,000 mph look like?

Bloodhound SSC Record Run

Bloodhound SSC will accelerate from rest using an EJ-200 jet engine, taking it up to 300mph.
At that point (a) the rocket will be ignited, so that it and the jet are operating simultaneously, thereby increasing the acceleration to well over 2g.

Having reached maximum speed (1,050mph), the rocket thrust will be stopped (point b), but the jet engine will continue burning for a few seconds.

During this brief period, the car will decelerate at about 1.5g. When the jet engine also stops (point c), the deceleration will peak at nearly 3g.

When the vehicle slows to subsonic speeds the aerodynamic drag will reduce dramatically, slowing the deceleration of the vehicle. Two additional deceleration peaks are shown on the curves (points d and e), indicating the release of two parachutes. At low speeds, below 200mph, hydraulically operated disc brakes can be used.

The land speed record is calculated from the average times of the car over two runs (to eliminate the effect of wind and other variables) so the car must then stop, refuel, turn around, and do the run all over again within an hour to claim the title.

Can they do it?

We’ll just have to wait to find out, but it sure looks like they’re taking steps in the right direction!

[Bloodhound SSC]