The
new design incorporates many changes from the last design which was posted
last year. Mainly the two propellant tanks are now located in tandem instead
of parallel. This makes the vehicle longer but also gives us a better control
over the Cg. as well as lowering the overall frontal area. The driver sits
in front of the tanks in a blast proof capsule made of Maraging Steel wrapped
with a composite. In the event of a mishap the capsule will be spit out by
the distorting chassis. There are no rockets or other deployment devices
on the capsule.
It is provided with a 6 foot diameter parachute of supersonic
capability in order to slow the capsule down and stabilizes it in a crash
scenario. The capsule will be painted florescent DayGlo orange for easier
visibility by a rescue crew.
There will only be an air speed indicator in the capsule and two red and green lights for the driver to watch, a green for engine function and a green for chute deployment. If either one are in a red light mode the vehicle will shut down and not run. All functions as well as attitude will be monitored by a computer and if all systems are not go the green light will not come on a run can not be commenced.
Underneath
the capsule=s
rear section as the capsule is
football shaped and tilted up at the rear
are the regulators which will supply gasses to the propellant vessels to
feed the engine. They are heavy so we want to mount them as forward as possible
in order to keep the Cg forward. In front of the capsule are the pressure
vessels which contain the gasses used to blow the fuel and oxidizer into
the LR-105 rocket engine. The fuel is Kerosene and the Oxidizer is liquid
Oxygen or LOX. The engine is run at half pressures and will develop 40,000
lbs. of thrust at what is virtually an idle.
The vehicle aerodynamic features are what make it my best design yet. First it has a great aspect or fineness ratio of about 22. It has a Cg of about .15 -.17. It has slightly
less than 9 square feet of frontal area and will weigh less than
8,000 lbs. with a full fuel load. It carries slightly over 3,000 lbs. of propellant.
On full thrust it will burn all the propellant in 22 seconds. It will accelerate
at slightly over 5.5 Gs for most of the run and taper down to 3Gs at burnout. In theory
it could hit Mach 3.
The
vehicle because it will be supersonic in seven seconds from a dead stop
is totally supersonic design which uses
shock to stabilize it in yaw, pitch
and roll. This is similar to how the B-70 Valkyrie bomber of the late 1960s
used shock to generate lift at the wings. For those of you who don=t
believe shock
can have a reacting effect on pushing a vehicle around that is the only
other vehicle I can relate Freedom LSRV to. R You might want to refer to
Newton's
third law of motion.
In a frontal view it is shaped like a bell with a 3 inch wide skirt at it's base. This keeps all the air striking the vehicle moving over the vehicle and not being able to get under the vehicle. Since there are no well defined sides or top in this bell shape it essentially is all top so all the is directed over the vehicle to generate negative lift. Any air
air that makes
it to the underside of the vehicle is tripped by the drum wide front wheels
and it becomes turbulent and of low pressure. There is a steering fin at
the very tip of the nose which moves in order to direct the vehicle. At
the nose it has authority and gets clean air flow while it does not induce
a rolling moment on the vehicle as steering fins on say the side of a 
missile
might. The steering fin is also turn able to preset or trim the vehicle
aerodynamically before a run. The leading edge of the steering fin is shaped
to aid in directing air over the top of the body. When the vehicle goes
supersonic a shock will form on the nose and the canopy of the vehicle
that will anchor them to the 
running surface during a supersonic run.
After the air leaves the length of the vehicle it is accelerated by the rocket engine's plume. The plume itself fires in a sort of tunnel formed by the rear wheels and this creates a low pressure area there which holds the wheels in place so they won’t want to wander. This stabilizes the rear of the craft. This is how I get away from the typical rocket car wide rear wheel rear track of the past. A rocket's thrust line is linear leading out from the injector and we can dial in a bit of pitch to develop down thrust if needed. Two fins acquired from an Honest John Missile are mounted canted at a 45 degree angle at the rear bottom of the vehicle. These fins will generate shock which will stabilize the vehicle in roll as well as put a drag moment under and behind the CG to keep the vehicle straight and pull it into the ground.
Other than these changes the design is basically the same as the last and you can read about the overall original design in the Freedom LSRV history pages......Waldo