Click on the above image to view still photos
Click on the above image to view still photos
I will explain the concepts in phases so as not to confuse the enthusiast or students of LSR.
Overall description:
Imagine LSRV is a bi propellant rocket powered land speed research vehicle with a theoretical top speed in excess of Mach 3. Its length is slightly over 50 feet with a width at the bottom of its bell shape of 36 inches. Its overall design uses super sonic shock and all the forces which will act upon the vehicle during a run to stabilize the vehicle and generate negative lift. It is powered by a highly modified LR-105 rocket engine originally used on the Convair, Atlas ICBM. The engine was originally built by the Rocketdyne Corporation. The fuel used is refined Kerosene and the Oxidizer is Liquid Oxygen commonly known as LOX. We will be using a pressure fed system using pressure vessels filled with inert gasses to blow the fuel and LOX into the engine. We will be running the engine at what is essentially at minimum power of approximately 40,000 lbs. of thrust. The duration is 34 seconds. The loaded vehicle weight will be less than 7,000 lbs.
The vehicle uses three sets of wheels. One set is located under the extreme nose. The second set is located under the center of gravity of the vehicle and the last set is located at the extreme aft of the vehicle on either side of the plume tunnel. The purpose of this is not only to carry the loads (because of the unique wheel designs which are low mass rings wrapped around an internal drum) but to create a teeter totter effect when the vehicle encounters impacts.
Aerodynamics:
Imagine LSRV has the same bell shaped body used in the Constitution LSRV and Freedom LSRV designs only it has become slightly more exaggerated. The purpose of this shape is to use all the air that strikes the vehicle to generate negative lift and minimize yaw. This happens because the top of the vehicle extends on a slope down the sides all the way down to a lip at the bottom of the car. This essentially makes the sides of the vehicle the top of the vehicle also. I am not the best orator in the world but look at the frontal photo to see what I am saying. Any air that slips around the edge of the lip is redirected out from underneath of the car by three supersonic Von Karman Ogive air dams which wrap around the bottom of all three sets of wheels. This creates extreme low pressure area under the entire length of the car and a high pressure is over the entire top of the car.
The Bell shape starts from the tip of the nose and goes all the way back to the rear of the vehicle. The upper side of the nose is a long sloping ogive curve which runs more than half the over-all length of the vehicle. The idea here is to use all impact air to generate a leading edge shock along the entire top of the nose. There are two bi wedge fins with end plates mounted low at the rear of the vehicle and canted upward 45 degrees. At speed these fins will impart a drag moment at the rear of the vehicle keeping the center of pressure of the vehicle behind the center of gravity. They also will generate a focused shock which will strike the ground and rebound away acting as a lever controlling the back of the vehicle in roll.
There is also a small long thin vertical fin mounted at the extreme front of the vehicle. Its purpose is to trim out the vehicle and aid in directional control at very high speed. It imparts a steering moment without trying to roll the vehicle in this position. It also has a great authority at this distance from the Cg. The steering moment also is below the Cg helping to keep the vehicle anchored to the ground.
Another novel design feature is the plume tunnel which the engine plume fires through. The high velocity of the rocket exhaust plume of 7,500 fps.will generate a low pressure area along the entire length of the tunnel holding the rear of the car stable and keeping the rear wheels from moving from side to side. Essentially a strong vacuum effect will be inside the tunnel holding the rear of the car in place. When the plume cuts out a vacuum will be formed in this area again by the blunt rear shape of the tunnel adding to the rear drag increasing rear stability at the end of the run.
The vehicle has an over-all frontal area of under 9 square feet. The Cd. Is yet to be determined but I expect it be quite low.
Chassis design:
The chassis is built from 140 linear feet of schedule 10 1/8 inch wall molly steel pipe as it serves double duty as the fuel tank. This chassis pressurized to 400 psi will be very rigid. If a crack or leak should occur, the tank pressure will drop and the engine will shut down automatically. Pressure switches on the chassis will ensure that. When the engine shuts down the fuel will slam forward under the Cg pulling the nose of the vehicle down using the mass of the fuel flowing forward. The LOX tank is a stainless steel vessel mounted on top of the fuel tank. This gives us a sort of concentric tank design similar to the X-15 rocket plane built by North American Aviation. Since the engine is pressurized using inert gasses (Nitrogen and Helium) these gasses are held in 8 Titanium spheres of various diameters which coincide with their position on the vehicle and its overall aerodynamic shape. They are generally located in the nose held in place on the chassis by Kevlar bras. They along with the regulators are in the nose to keep the Cg. Forward.
Driver Safety:
The driver will be piloting the most energetic land vehicle ever designed by man and a LSRV car that will be virtually unbeatable. So safety is a real concern. The driver is suspended in a Kevlar hammock suspended inside a blast proof, football shaped capsule. The capsule is made of Marigine steel wrapped with composite. In the case of an explosion or crash the capsule will be thrown from the vehicle and deploy its own parachutes to slow it down. The capsule is isolated from vehicle impacts and movement by having its own suspension using standard automobile shock absorbers. The vehicle itself will have a very limited suspension in order to minimize frequency oscillation and bouncing. The capsule will be painted bright orange and be the only thing that the safety crew will focus on in case of a catastrophe. The capsule will have a seven foot diameter supersonic parachute originally used on the Subroc rocket torpedo which is a 900 mile per hour rocket.
Braking:
Braking for the vehicle is handle by a reefed 17 foot diameter supersonic parachute originally developed for supersonic hydrogen bomb deployment. There is also a back up parachute. Dead stopping is accomplished by a pneumatic drag plate similar to the rake brake I used in Sonic Wind the ice rocket racer.
