The Bullet Project
Encyclopedia
The Bullet Project is a project that aims to stimulate the minds of Australia's future generations. This is to be achieved through the construction of a vehicle called The Silver Bullet RV-1. The Project founders, Paul Noone a vehicle restorer/builder and Mark Stephenson Specialist in Brand Development, Multimedia Marketing, Concepts, Business Services and Presentation, are building the vehicle using Australian technology and resources.
propelled land vehicle with a top speed in excess of 1,000 mph. The RV-1 will incorporate the latest knowledge in vehicle aerodynamics and chassis design, as well as break new ground in wheel design and driver safety. New ground being broken by the Bullet Project team includes a wheel with an internal suspension system where only the outer rim rotates, and a fireproof
blast-resistant ejectable driver capsule
that maintains the driver in a breathable atmosphere
.
The Bullet Project, in comparison to Australian, British, and American teams which all have vehicles now in the build or testing phase 44 feet in length or longer and weighing six tons or more, is taking a radically different approach to the problem of building a supersonic car. The target dry weight of RV-1 is three tons with a rocket propellant capacity of approximately two tons. Bloodhound SSC
, a British project lead by Richard Noble
, is a combination jet and rocket vehicle 44 feet long with a fully fueled weight of approximately seven tons. Aussie Invader 5R, a pure rocket vehicle under construction by Australian land speed record holder Rosco McGlashan
, is 50 feet long with a dry weight in excess of seven tons. The North American Eagle, a jet vehicle converted from an F-104 Starfighter
, is 56 feet long and weighs 6.5 tons. The other American project, the Sonic Wind LSRV rocket car now under construction by Waldo Stakes, is 47 feet long with a dry weight of 3.5 tons.
Originally, we also contemplated a design for a vehicle 60 feet long. However, through studies of various iterations of much lighter vehicles, beginning with the smallest one possible then working up until arriving at the minimum size that would still hold enough rocket propellant for 1,000 mph, is how the RV-1 has arrive at its current design.
engines were selected due to their inherent compactness and light weight as well as eliminating the need for a large and destabilizing air inlet duct. The drawback to rocket engines is the large mass of fuel and oxidizer they require, and the potential for explosion. The amount of rocket propellant
needed for RV-1 is minimized by keeping the size and weight of the vehicle as small as possible, while still storing enough energy onboard to achieve the target speed. RV-1 will have a capacity for approximately 4,200 lbs combined weight of liquid oxygen
(LOX) and kerosene. This will be sufficient to support a continuous thrust
of 35,000 lbs for a minimum of 30 seconds or 50,000 lbs for a minimum of 17 seconds. The thrust will be variable so that it can be tailored to match the planned trajectory for each run. Trajectories will be plotted based on drag curves calculated through detailed computational fluid dynamics (CFD) analysis. To avoid the mechanical complexity of a pump-fed system, a blowdown system will be used with nitrogen pressurizing the LOX
and kerosene
tanks. The explosion hazard is minimized by placement of the LOX and kerosene tanks in separate compartments, divided by bulkheads and further separated with the cockpit and the nitrogen tanks.
's third jet car (1996). The primary structural element for the RV-1 chassis will be a large diameter tube that houses the main LOX tank, the nitrogen tanks, the cockpit, the kerosene tank, and the rocket motors. The tube will also provide the attachment points for the forward LOX tanks, the wheels, the braking ballutes, and the body shell. It is currently planned for the tube to be of carbon fiber composite construction, although consideration is also being given to fabricating it using rolled and welded magnesium. Magnesium has the same density as carbon fiber, but is not as stiff and so would have to be thicker, as well as protected against corrosion from salt. The cockpit will be a sealed and self-contained capsule that drops in a compartment located near the mid-point of the vehicle.
Mickey Thompson used a large diameter tube as a backbone for one of his Indy cars. It had clampen on suspension and other components. The tube gave great rigidity for light weight.
Modern monocoque design with carbon fibes would make this impractical.
and blast-resistant capsule
, inspired by the example of the Scott Crossfield incident in the X-15 rocket plane, consideration was then given to making the capsule ejectable. After studying examples from both aviation and 250 mph drag boat racing of ejectable or separable capsules, it was decided to pattern the capsule separation for RV-1 largely after the drag boat model, in which the capsule separates only after a crash has already initiated. However, due to the much higher speeds and different motions expected in comparison to a drag boat if RV-1 were to crash, it was decided to incorporate both a mechanism for actively ejecting the capsule and an aerodynamic decelerator. Banks of compressed air
rams on each side of the capsule will serve as the ejection mechanism, with tilt switches mounted in the horizontal and vertical planes acting to initiate ejection without driver intervention. In the ejection sequence currently envisioned, if the RV-1 pitches or rolls beyond preset limits, a tilt switch will open a solenoid valve that releases compressed nitrogen
into the banks of rams. As the capsule is launched outward, the tension from a steel cable lanyard attached between the capsule and the chassis will pull a mechanism in the capsule that releases a ballute to decelerate and stabilize the capsule.
wheel, based on a rim sandwiched between two disks, the lightest that could be expected for a 30 inch diameter 8 inch wide wheel was still 230 lbs, the decision was made to explore reducing rotating mass
by going to a design where only the outer rim rotates. This had the ripple effect of making an internal suspension
system practical, which in turn freed up the volume that would otherwise be occupied by a conventional suspension system. To generate a stable and consistent steering response, tireless wheels must plane on the surface of the track instead of plowing ruts. The wheel width of 8 inches for RV-1 was determined by reviewing the experience of other teams to run vehicles with tireless wheels on a salt flat. Based on the experiences of these other teams, it was felt 8 inches should be wide enough to support a five tons gross weight vehicle running on dry salt without cutting ruts. The wheel rim will rotate on air bearings placed around the perimeter of a bearing block that also houses the slide which serves as the suspension system. Rubber cushions on the top and bottom of the slide permit an up and down movement of +/- 1 inch. The sides of the slide will serve as adjustable friction dampeners to control bounce.
The channel formed between the tail fins is intended to augment vehicle downforce at speeds in excess of Mach 1 by taking advantage of a phenomenon called compression lift. To generate compression lift
, air is forced outwards by a center body, in this case the tunnel on top of the vehicle housing the rocket propellant feed lines, against two vertical aerodynamic surfaces.
Downforce
is further enhanced through the two canard wings located beside the cockpit. The canard wings for the RV-1 are based on studies of disk wings. The shape permits a large amount of surface area while maintaining a short span. So that the wing angle of attack can be adjusted while the vehicle is in motion, the wings pivot from the front moved hydraulic actuators attached at the rear. This combination of a short span and two-point attachment provides a very rigid system which reduces the potential for flutter, a destructive aerodynamic phenomenon that results in rapid uncontrolled motion which can lead to structural failure.
salt flats, and the length of the course needed. A smaller vehicle can accelerate quicker and stop in a shorter distance. Minimizing the stopping distance maximizes the margin for error, which means The Bullet Project don't have to search all over the world for a track that allows a twelve or fourteen mile course because it can be attempted in nine miles on Lake Gairdner.
Design and Development
The Project vehicle The Silver Bullet RV-1, a 30 foot four-wheel steerable liquid oxygen and kerosene rocketRocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...
propelled land vehicle with a top speed in excess of 1,000 mph. The RV-1 will incorporate the latest knowledge in vehicle aerodynamics and chassis design, as well as break new ground in wheel design and driver safety. New ground being broken by the Bullet Project team includes a wheel with an internal suspension system where only the outer rim rotates, and a fireproof
Fireproof
-Track List for Original 2002 Release:# "Fireproof" – 3:46# "Just 2 Get By" – 4:17# "Echelon" – 3:25# "Stay Up" – 3:40# "Behind Closed Doors" – 2:55# "Epidemic" – 3:14# "Hindsight" – 2:57# "Light at My Feet" – 3:28# "A Shame" – 3:17...
blast-resistant ejectable driver capsule
Capsule
-Anatomy:* an eggshell* Articular capsules - every diarthrodial joint possesses a fibrous or ligamentous capsule, lined with synovial membrane, attached to the adjacent ends of the articulating bones* the sac that encloses the crystalline lens of the eye...
that maintains the driver in a breathable atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
.
The Bullet Project, in comparison to Australian, British, and American teams which all have vehicles now in the build or testing phase 44 feet in length or longer and weighing six tons or more, is taking a radically different approach to the problem of building a supersonic car. The target dry weight of RV-1 is three tons with a rocket propellant capacity of approximately two tons. Bloodhound SSC
Bloodhound SSC
Bloodhound SSC is the name of a project aiming to break the land speed record with a pencil-shaped car powered by a jet engine and a rocket designed to reach approximately...
, a British project lead by Richard Noble
Richard Noble
Richard Noble, OBE was the holder of the land speed record between 1983 and 1997, and was the project director of ThrustSSC, the vehicle which holds the current land speed record, set at Black Rock Desert, Nevada in 1997....
, is a combination jet and rocket vehicle 44 feet long with a fully fueled weight of approximately seven tons. Aussie Invader 5R, a pure rocket vehicle under construction by Australian land speed record holder Rosco McGlashan
Rosco McGlashan
Rosco McGlashan OAM is an Australian drag racing record-holder, who currently holds the Australian land speed record at 500 mph . This record was set on the 27 March 1994 on the dry salt flats of Lake Gairdner, South Australia northwest of Adelaide.- Aussie Invader II :McGlashan set the...
, is 50 feet long with a dry weight in excess of seven tons. The North American Eagle, a jet vehicle converted from an F-104 Starfighter
Starfighter
"Starfighter" is a science fiction term used to describe small, fast, usually one-manned craft designed for armed combat .The appearance and use of fictional starfighters is often modeled on fighter aircraft, with little regard for the actual physics of spaceflight...
, is 56 feet long and weighs 6.5 tons. The other American project, the Sonic Wind LSRV rocket car now under construction by Waldo Stakes, is 47 feet long with a dry weight of 3.5 tons.
Originally, we also contemplated a design for a vehicle 60 feet long. However, through studies of various iterations of much lighter vehicles, beginning with the smallest one possible then working up until arriving at the minimum size that would still hold enough rocket propellant for 1,000 mph, is how the RV-1 has arrive at its current design.
Power plant
RocketRocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...
engines were selected due to their inherent compactness and light weight as well as eliminating the need for a large and destabilizing air inlet duct. The drawback to rocket engines is the large mass of fuel and oxidizer they require, and the potential for explosion. The amount of rocket propellant
Propellant
A propellant is a material that produces pressurized gas that:* can be directed through a nozzle, thereby producing thrust ;...
needed for RV-1 is minimized by keeping the size and weight of the vehicle as small as possible, while still storing enough energy onboard to achieve the target speed. RV-1 will have a capacity for approximately 4,200 lbs combined weight of liquid oxygen
Liquid oxygen
Liquid oxygen — abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries — is one of the physical forms of elemental oxygen.-Physical properties:...
(LOX) and kerosene. This will be sufficient to support a continuous thrust
Thrust
Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction the accelerated mass will cause a force of equal magnitude but opposite direction on that system....
of 35,000 lbs for a minimum of 30 seconds or 50,000 lbs for a minimum of 17 seconds. The thrust will be variable so that it can be tailored to match the planned trajectory for each run. Trajectories will be plotted based on drag curves calculated through detailed computational fluid dynamics (CFD) analysis. To avoid the mechanical complexity of a pump-fed system, a blowdown system will be used with nitrogen pressurizing the LOX
Lox
Lox is salmon fillet that has been cured. In its most popular form, it is thinly sliced—less than in thickness—and, typically, served on a bagel, often with cream cheese, onion, tomato, cucumber and capers...
and kerosene
Kerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...
tanks. The explosion hazard is minimized by placement of the LOX and kerosene tanks in separate compartments, divided by bulkheads and further separated with the cockpit and the nitrogen tanks.
Chassis design
A conventional four-wheel layout was chosen to avoid stability problems that have been demonstrated in the dynamics of ultranarrow front track/ultrawide rear track configurations, such as the Budweiser rocket car (1979) and Craig BreedloveCraig Breedlove
Craig Breedlove is a five-time world land speed record holder. He was the first to reach , , and , using several turbojet-powered vehicles, all named Spirit of America.-Land vehicle speed records :...
's third jet car (1996). The primary structural element for the RV-1 chassis will be a large diameter tube that houses the main LOX tank, the nitrogen tanks, the cockpit, the kerosene tank, and the rocket motors. The tube will also provide the attachment points for the forward LOX tanks, the wheels, the braking ballutes, and the body shell. It is currently planned for the tube to be of carbon fiber composite construction, although consideration is also being given to fabricating it using rolled and welded magnesium. Magnesium has the same density as carbon fiber, but is not as stiff and so would have to be thicker, as well as protected against corrosion from salt. The cockpit will be a sealed and self-contained capsule that drops in a compartment located near the mid-point of the vehicle.
Mickey Thompson used a large diameter tube as a backbone for one of his Indy cars. It had clampen on suspension and other components. The tube gave great rigidity for light weight.
Modern monocoque design with carbon fibes would make this impractical.
Driver safety
Once it was determined that the cockpit would be a sealed fireproofFireproof
-Track List for Original 2002 Release:# "Fireproof" – 3:46# "Just 2 Get By" – 4:17# "Echelon" – 3:25# "Stay Up" – 3:40# "Behind Closed Doors" – 2:55# "Epidemic" – 3:14# "Hindsight" – 2:57# "Light at My Feet" – 3:28# "A Shame" – 3:17...
and blast-resistant capsule
Capsule
-Anatomy:* an eggshell* Articular capsules - every diarthrodial joint possesses a fibrous or ligamentous capsule, lined with synovial membrane, attached to the adjacent ends of the articulating bones* the sac that encloses the crystalline lens of the eye...
, inspired by the example of the Scott Crossfield incident in the X-15 rocket plane, consideration was then given to making the capsule ejectable. After studying examples from both aviation and 250 mph drag boat racing of ejectable or separable capsules, it was decided to pattern the capsule separation for RV-1 largely after the drag boat model, in which the capsule separates only after a crash has already initiated. However, due to the much higher speeds and different motions expected in comparison to a drag boat if RV-1 were to crash, it was decided to incorporate both a mechanism for actively ejecting the capsule and an aerodynamic decelerator. Banks of compressed air
Compressed air
Compressed air is air which is kept under a certain pressure, usually greater than that of the atmosphere. In Europe, 10 percent of all electricity used by industry is used to produce compressed air, amounting to 80 terawatt hours consumption per year....
rams on each side of the capsule will serve as the ejection mechanism, with tilt switches mounted in the horizontal and vertical planes acting to initiate ejection without driver intervention. In the ejection sequence currently envisioned, if the RV-1 pitches or rolls beyond preset limits, a tilt switch will open a solenoid valve that releases compressed nitrogen
Nitrogen
Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
into the banks of rams. As the capsule is launched outward, the tension from a steel cable lanyard attached between the capsule and the chassis will pull a mechanism in the capsule that releases a ballute to decelerate and stabilize the capsule.
Wheels and suspension
At 1,000 mph, a 30 inch diameter wheel will be turning over 10,000 rpm, generating a centrifugal force of 50,000g at the rim. When it was found that even with a hollow all carbon fiberCarbon fiber
Carbon fiber, alternatively graphite fiber, carbon graphite or CF, is a material consisting of fibers about 5–10 μm in diameter and composed mostly of carbon atoms. The carbon atoms are bonded together in crystals that are more or less aligned parallel to the long axis of the fiber...
wheel, based on a rim sandwiched between two disks, the lightest that could be expected for a 30 inch diameter 8 inch wide wheel was still 230 lbs, the decision was made to explore reducing rotating mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
by going to a design where only the outer rim rotates. This had the ripple effect of making an internal suspension
Suspension
Suspension may refer to:In science and engineering:*Suspension , in mathematics*Suspension , in mathematics*Suspension , mixture of two chemicals with the property that one does not rapidly settle out...
system practical, which in turn freed up the volume that would otherwise be occupied by a conventional suspension system. To generate a stable and consistent steering response, tireless wheels must plane on the surface of the track instead of plowing ruts. The wheel width of 8 inches for RV-1 was determined by reviewing the experience of other teams to run vehicles with tireless wheels on a salt flat. Based on the experiences of these other teams, it was felt 8 inches should be wide enough to support a five tons gross weight vehicle running on dry salt without cutting ruts. The wheel rim will rotate on air bearings placed around the perimeter of a bearing block that also houses the slide which serves as the suspension system. Rubber cushions on the top and bottom of the slide permit an up and down movement of +/- 1 inch. The sides of the slide will serve as adjustable friction dampeners to control bounce.
Aerodynamics
To assure yaw stability, the center of pressure must be behind the center of gravity. The RV-1 design accomplishes this through two large tail fins and moving the center of gravity as far forward as possible through placement of the heaviest components in the front half of the vehicle. To counteract any lift that might be generated as shockwaves form at transonic and supersonic speeds, various methods of generating downforce are being incorporated, principally the shape of the nose and the use of canard wings. However, the use of ground effects tunnels on the underside of the nose is also being considered.The channel formed between the tail fins is intended to augment vehicle downforce at speeds in excess of Mach 1 by taking advantage of a phenomenon called compression lift. To generate compression lift
Compression lift
In aerodynamics, compression lift refers to an aircraft that uses shock waves generated by its own supersonic flight to generate lift. This can lead to dramatic improvements in lift for supersonic/hypersonic aircraft, which often fly at high altitudes and thus suffer from decreased lift due to the...
, air is forced outwards by a center body, in this case the tunnel on top of the vehicle housing the rocket propellant feed lines, against two vertical aerodynamic surfaces.
Downforce
Downforce
Downforce is a downwards thrust created by the aerodynamic characteristics of a car. The purpose of downforce is to allow a car to travel faster through a corner by increasing the vertical force on the tires, thus creating more grip....
is further enhanced through the two canard wings located beside the cockpit. The canard wings for the RV-1 are based on studies of disk wings. The shape permits a large amount of surface area while maintaining a short span. So that the wing angle of attack can be adjusted while the vehicle is in motion, the wings pivot from the front moved hydraulic actuators attached at the rear. This combination of a short span and two-point attachment provides a very rigid system which reduces the potential for flutter, a destructive aerodynamic phenomenon that results in rapid uncontrolled motion which can lead to structural failure.
Conclusion
Setting the World Land Speed Record requires two runs in opposite directions within one hour through a mile speed trap located in the middle of the course. There is no minimum course length. We believe that minimizing the size of the vehicle also minimizes other problems, such as building the vehicle, transport of the vehicle to the Lake GairdnerLake Gairdner
Lake Gairdner is a large endorheic lake in central South Australia, and is considered the fourth largest salt lake in Australia when it is flooded....
salt flats, and the length of the course needed. A smaller vehicle can accelerate quicker and stop in a shorter distance. Minimizing the stopping distance maximizes the margin for error, which means The Bullet Project don't have to search all over the world for a track that allows a twelve or fourteen mile course because it can be attempted in nine miles on Lake Gairdner.
See also
- List of vehicle speed records
- Land speed recordLand speed recordThe land speed record is the highest speed achieved by a wheeled vehicle on land. There is no single body for validation and regulation; in practice the Category C flying start regulations are used, officiated by regional or national organizations under the auspices of the Fédération...
- Thrust SSC Current record holder since 1997
- North American Eagle Project aiming for 808 mi/h.
- Jetblack A New Zealand contender aiming for testing in 2015