25-08-2014, 03:41 PM
Flying car On Seminar Report
[attachment=67013]
INTRODUCTION
‘Flying car’, ‘roadable aircraft’, ‘dual-mode vehicle’ and other terms are used to describe the all-purpose vehicle that can fly like an airplane and drive on the highway like an automobile. Make it amphibious and we have the perfect all-purpose vehicle! Nevertheless, this might be taking our ideas a bit too far.
It has long been the dream of aviation and automobile enthusiasts to have a vehicle that will bring them the best of both worlds. Many drivers stuck in rush hour traffic have fantasies about being able to push a button and watch their car’s wings unfurl as they lift above the stalled cars in front of them. Just as many pilots who have been grounded at an airport far from home by inclement weather have wished for some way to wheel their airplane out onto the highway and drive home. This yearning has resulted in many designs for roadable aircraft since as early as 1906.
A designer of a flying car will encounter many obstacles, including conflicting regulations for aircraft and automobiles. As an automobile, such a vehicle must be able to fit within the width of a lane of traffic and pass under highway overpasses. It must be able to keep up with normal highway traffic and meet all safety regulations. It must also satisfy vehicle exhaust emission standards for automobiles. Therefore, the wings must be able to fold (or retract) and the tail or canard surfaces may have to be stowable. The emission standards and crashworthiness requirements will add weight to the design. The need for an engine/transmission system that can operate in the stop and go, accelerate and decelerate environment of the automobile will also add system complications and weight.
For flight, the roadable aircraft must be lightweight and easy to fly. It must have a speed range at least comparable to existing general aviation airplanes. Conversion from aircraft to car or vice versa must be doable by a single person and the engine must be able to operate using either aviation fuel or auto fuel. Ground propulsion must be through the wheels and not via propeller or jet which would present a danger to nearby people, animals or other vehicles
DESIGN APPROACH
While some people use the terms Flying car and roadable aircraft interchangeably, or use the latter term to bypass the science fiction connotations of the former, they are explicitly two quite different concepts. One wishing to design such vehicles must first decide which approach is appropriate. The ‘flying car’ is primarily a car in which the driver has the option of taking to the air when desired or necessary. The ‘roadable aircraft’ is an airplane that also happens to be capable of operation on the highway.
In the past, most designs have actually been for roadable aircraft. They started out looking like conventional airplanes but with wings and possibly with tails that could be retracted or folded. Alternatively, they may be removed and towed in a trailer when the vehicle is operated on the road. Several such vehicles have been designed and built. A few, such as the Taylor Aerocar1 or the Fulton Airphibian, have been certified for use in flight and on the highway. Both types of vehicle have been sold to the public. The roadable aircraft is meant to be primarily an airplane but with the capability of being driven on roads to and from the airport. It must also be capable of getting the pilot and passengers to their desired destination on the highway when the weather prevents flight. As such, it is a vehicle primarily sold to licensed pilots. They would use its on-road capabilities in a limited manner, and not as a substitute for the family automobile for everyday trips to the supermarket. Typical problems with such designs have been their poor performance both in the air and on the road. Also, there has been in the past a reluctance of insurance companies to write policies which will cover their operation in both environments
.
The ‘flying car’, unlike the roadable aircraft, has proved to be more of a fantasy than an achievable reality. A key element in the development of a successful flying car is designing a control system that will enable a ‘driver’ who may not be a trained pilot to operate the vehicle in either mode of travel. This virtually necessitates a ‘category III capable’ automated control system for the vehicle. This must provide a ‘departure-to destination’ flight control, navigation and communication environment. Many experts feel that such a design is possible today, but only at high cost. Ideally, if the ‘flying car’ is to become the family car, it must have a price that is at least comparable to a luxury automobile (preferably less than 25 percent of the cost of the cheapest current four passenger general aviation aircraft).
Both the flying car and the roadable aircraft concepts usually assume a self-contained system capable of simple manual or even automated conversion between the car and airplane modes. A third choice is the dual-mode design which is capable of operation on the road or in the air but does not necessarily carry all the hardware needed for both modes with it at all times. One such vehicle was the Convair/Stinson CV-118 Aircar.Designed in the 1940s, it combined a very modern looking fiberglass body car with a wing/tail/engine structure that could be attached to the roof of the car for flight. This design successfully flew, and operated well on the highway, but was a victim of high cost and changing corporate goals for its manufacturer.
DESIGN CONSIDERATION
Some of the specifications to be determined by the design approach are:
Range
Endurance
Rate of climb
Cruise speed in air
Cruise speed in land
Airworthiness standards
Automobile safety and emissions.
Additional challenges to be noted are
• The need to have acceptable in-flight wing aerodynamics while being able to retract,
fold, or detach and stow the wing for road travel,
• The need to ‘rotate’ on take-off,
• The need to find an engine/transmission combination which could meet the conflicting
demands of ground and air travel,
• The need for dual-mode control systems, and the need to meet rigorous stability and
performance requirements in both modes of travel.
The design of a satisfactory wing is a dominant part of any roadable aircraft layout. As a ‘car’ the vehicle must fit into standard roadway widths. The resulting vehicle footprint (aspect ratio) is less than unity. This is regarded as inefficient for an aircraft wing planform. A wing of reasonable aspect ratio must then be capable of being extended from the body (fuselage) for flight and somehow stowed for highway use. There are many ways to do this including folding wings, rotating wings, telescoping wings, and detachable wings. These could be stored in, under, or over the car configuration. Alternatively, they could be towed behind the car. All such designs impose structural compromise and weight penalties. The use of the wing for a fuel tank location would also be ruled out.
DESIGN CONCEPTS
Convair Aircar
Attempts at roadable aircraft have been made since the advent of the airplane itself. Only fourteen years after the Wright brothers first flew, Glenn Curtiss tried to develop a flying automobile. His design was exhibited at the 1917 Pan-American Aeronautic Exposition in New York. This vehicle was abandoned after the flight characteristics were deemed unacceptable. George Spratt built the first flying roadable aircraft by using an existing aircraft and adding a pivoting wing. This simply allowed the existing aircraft to maneuver down the road without side obstruction. Waldo Waterman was the first person ever to be granted a patent on a roadable
Taylor Aerocar
Aerocar International's Aerocar (often called the Taylor Aerocar) was an American roadable aircraft, designed and built by Moulton Taylor in Longview, Washington, in 1949. It is the most successful and probably the most famous "flying car" design to date. Although six examples were built, the Aerocar never entered production.
Design and Development
Taylor's design of a roadable aircraft dates back to 1946. During a trip to Delaware, he met inventor Robert E. Fulton, Jr., who had designed an earlier roadable airplane, the Airphibian. Taylor recognized that the detachable wings of Fulton’s design would be better replaced by folding wings. His prototype Aerocar utilized folding wings that allowed the road vehicle to be convertible into flight mode in five minutes by one person. When the rear licence plate was flipped up, the operator could connect the propeller shaft and attach a pusher propeller. The same engine drives the front wheels through a three-speed manual transmission. When operated as an aircraft, the road transmission is simply left in neutral (though backing up during taxiing is possible by using reverse gear.) On the road, the wings and tail unit were designed to be towed behind the vehicle. Aerocars can drive up to 60 miles per hour and have a top airspeed of 110 miles per hour.
Moller skycar
The Moller Sky car is a prototype personal VTOL (vertical take-off and landing) aircraft a "flying car" called a "Volantor" by its inventor Paul Moller, who has been attempting to develop such vehicles for forty years. The design calls for four fans encasing the propellers, which is safer to bystanders and more efficient at low speeds.
The craft said to be currently under development, the M400, is purported to ultimately transport four people; single-seat up to six-seat variations are also planned. It is described as a car since it is aimed at being a popular means of transport for anyone who can drive, incorporating automated flight controls. It is proposed that in a model for the general public, the driver may only input direction and speed. Piloting knowledge would be un-necessary; however, training will be required.
Further, developers claim that by using eight inexpensive Wankel rotary engines - compared to jet engines, the vehicle's price may eventually fall close to that of a luxury car ($100,000). The fuel consumption is claimed to be 20 miles per gallon similar to that of a big car but this has been calculated as unrealistic. According to the developers, operation of a Skycar will produce as much noise as traffic on a nearby freeway when taking off, and this will only last for a few seconds, because it climbs so quickly
Operation
A Skycar is not piloted like a traditional fixed wing airplane, and has only two hand-operated controls, which the pilot uses to inform the computer control system of his desired flight maneuvers. The Skycar's ducted fans deflect air vertically for takeoff and horizontally for forward flight
Rotapower engines
The engines to be used are being developed by a separate Moller company called Freedom Motors. They are Wankel engines they call "Rotapower" which have a direct drive to a propulsion fan. Each fan is contained in Kevlar-lined housings with intake screens to provide protection to bystanders. The Skycar has four engine nacelles, each with two computer-controlled Rotapower engines. All eight engines operate independently and, allegedly, will allow for a vertical controlled landing should any one fail.
The Rotapower Wankel engine would have the ability to operate on any fuel. Earlier Rotapower models used gasoline
Terrafugia-Transition
The Transition is a light sport, roadable aircraft under development by Terrafugia, a small start-up company based in Woburn, Massachusetts.
The Rotax 912S piston engine powered, carbon-fiber vehicle is planned to have a flight range of 400 nmi (460 mi; 740 km) using automotive grade unleaded gasoline and a cruising flight speed of 115 mph (100 kn; 185 km/h). It does not come with an autopilot.
On the highway, it can drive up to 65 miles per hour (105 km/h) to keep up with traffic. The Transition Proof of Concept's folded dimensions of 6 ft 9 in (2.1 m) high, 6 ft 8 in (2.0 m) wide and 18 ft 9 in (5.7 m) long are designed to fit within a standard household garage. When operated as a car, the engine powers the front wheel drive. In flight, the engine drives a pusher propeller. The Transition's layout, with folding wings, pusher propeller and twin tail, is similar to experimental aircraft N8072 built by Dr. Lewis A. Jackson in Xenia, Indiana during the 1960s.
The experimental Transition Proof of Concept's first flight was successful and took place under FAA supervision at Plattsburgh International Airport in upstate New York using FAA tail number N302TF. First customer delivery, as of March 2009, is planned for 2011
CONCLUSION
The flying car concepts will require some more time to be in reality.
Roadable aircrafts design and development are feasible.
Cost of roadable aircrafts play a vital role in their success.
The success of roadable aircrafts will end uncertain weather, rising costs, and ground transportation hassles on each end of the flight
[attachment=67013]
INTRODUCTION
‘Flying car’, ‘roadable aircraft’, ‘dual-mode vehicle’ and other terms are used to describe the all-purpose vehicle that can fly like an airplane and drive on the highway like an automobile. Make it amphibious and we have the perfect all-purpose vehicle! Nevertheless, this might be taking our ideas a bit too far.
It has long been the dream of aviation and automobile enthusiasts to have a vehicle that will bring them the best of both worlds. Many drivers stuck in rush hour traffic have fantasies about being able to push a button and watch their car’s wings unfurl as they lift above the stalled cars in front of them. Just as many pilots who have been grounded at an airport far from home by inclement weather have wished for some way to wheel their airplane out onto the highway and drive home. This yearning has resulted in many designs for roadable aircraft since as early as 1906.
A designer of a flying car will encounter many obstacles, including conflicting regulations for aircraft and automobiles. As an automobile, such a vehicle must be able to fit within the width of a lane of traffic and pass under highway overpasses. It must be able to keep up with normal highway traffic and meet all safety regulations. It must also satisfy vehicle exhaust emission standards for automobiles. Therefore, the wings must be able to fold (or retract) and the tail or canard surfaces may have to be stowable. The emission standards and crashworthiness requirements will add weight to the design. The need for an engine/transmission system that can operate in the stop and go, accelerate and decelerate environment of the automobile will also add system complications and weight.
For flight, the roadable aircraft must be lightweight and easy to fly. It must have a speed range at least comparable to existing general aviation airplanes. Conversion from aircraft to car or vice versa must be doable by a single person and the engine must be able to operate using either aviation fuel or auto fuel. Ground propulsion must be through the wheels and not via propeller or jet which would present a danger to nearby people, animals or other vehicles
DESIGN APPROACH
While some people use the terms Flying car and roadable aircraft interchangeably, or use the latter term to bypass the science fiction connotations of the former, they are explicitly two quite different concepts. One wishing to design such vehicles must first decide which approach is appropriate. The ‘flying car’ is primarily a car in which the driver has the option of taking to the air when desired or necessary. The ‘roadable aircraft’ is an airplane that also happens to be capable of operation on the highway.
In the past, most designs have actually been for roadable aircraft. They started out looking like conventional airplanes but with wings and possibly with tails that could be retracted or folded. Alternatively, they may be removed and towed in a trailer when the vehicle is operated on the road. Several such vehicles have been designed and built. A few, such as the Taylor Aerocar1 or the Fulton Airphibian, have been certified for use in flight and on the highway. Both types of vehicle have been sold to the public. The roadable aircraft is meant to be primarily an airplane but with the capability of being driven on roads to and from the airport. It must also be capable of getting the pilot and passengers to their desired destination on the highway when the weather prevents flight. As such, it is a vehicle primarily sold to licensed pilots. They would use its on-road capabilities in a limited manner, and not as a substitute for the family automobile for everyday trips to the supermarket. Typical problems with such designs have been their poor performance both in the air and on the road. Also, there has been in the past a reluctance of insurance companies to write policies which will cover their operation in both environments
.
The ‘flying car’, unlike the roadable aircraft, has proved to be more of a fantasy than an achievable reality. A key element in the development of a successful flying car is designing a control system that will enable a ‘driver’ who may not be a trained pilot to operate the vehicle in either mode of travel. This virtually necessitates a ‘category III capable’ automated control system for the vehicle. This must provide a ‘departure-to destination’ flight control, navigation and communication environment. Many experts feel that such a design is possible today, but only at high cost. Ideally, if the ‘flying car’ is to become the family car, it must have a price that is at least comparable to a luxury automobile (preferably less than 25 percent of the cost of the cheapest current four passenger general aviation aircraft).
Both the flying car and the roadable aircraft concepts usually assume a self-contained system capable of simple manual or even automated conversion between the car and airplane modes. A third choice is the dual-mode design which is capable of operation on the road or in the air but does not necessarily carry all the hardware needed for both modes with it at all times. One such vehicle was the Convair/Stinson CV-118 Aircar.Designed in the 1940s, it combined a very modern looking fiberglass body car with a wing/tail/engine structure that could be attached to the roof of the car for flight. This design successfully flew, and operated well on the highway, but was a victim of high cost and changing corporate goals for its manufacturer.
DESIGN CONSIDERATION
Some of the specifications to be determined by the design approach are:
Range
Endurance
Rate of climb
Cruise speed in air
Cruise speed in land
Airworthiness standards
Automobile safety and emissions.
Additional challenges to be noted are
• The need to have acceptable in-flight wing aerodynamics while being able to retract,
fold, or detach and stow the wing for road travel,
• The need to ‘rotate’ on take-off,
• The need to find an engine/transmission combination which could meet the conflicting
demands of ground and air travel,
• The need for dual-mode control systems, and the need to meet rigorous stability and
performance requirements in both modes of travel.
The design of a satisfactory wing is a dominant part of any roadable aircraft layout. As a ‘car’ the vehicle must fit into standard roadway widths. The resulting vehicle footprint (aspect ratio) is less than unity. This is regarded as inefficient for an aircraft wing planform. A wing of reasonable aspect ratio must then be capable of being extended from the body (fuselage) for flight and somehow stowed for highway use. There are many ways to do this including folding wings, rotating wings, telescoping wings, and detachable wings. These could be stored in, under, or over the car configuration. Alternatively, they could be towed behind the car. All such designs impose structural compromise and weight penalties. The use of the wing for a fuel tank location would also be ruled out.
DESIGN CONCEPTS
Convair Aircar
Attempts at roadable aircraft have been made since the advent of the airplane itself. Only fourteen years after the Wright brothers first flew, Glenn Curtiss tried to develop a flying automobile. His design was exhibited at the 1917 Pan-American Aeronautic Exposition in New York. This vehicle was abandoned after the flight characteristics were deemed unacceptable. George Spratt built the first flying roadable aircraft by using an existing aircraft and adding a pivoting wing. This simply allowed the existing aircraft to maneuver down the road without side obstruction. Waldo Waterman was the first person ever to be granted a patent on a roadable
Taylor Aerocar
Aerocar International's Aerocar (often called the Taylor Aerocar) was an American roadable aircraft, designed and built by Moulton Taylor in Longview, Washington, in 1949. It is the most successful and probably the most famous "flying car" design to date. Although six examples were built, the Aerocar never entered production.
Design and Development
Taylor's design of a roadable aircraft dates back to 1946. During a trip to Delaware, he met inventor Robert E. Fulton, Jr., who had designed an earlier roadable airplane, the Airphibian. Taylor recognized that the detachable wings of Fulton’s design would be better replaced by folding wings. His prototype Aerocar utilized folding wings that allowed the road vehicle to be convertible into flight mode in five minutes by one person. When the rear licence plate was flipped up, the operator could connect the propeller shaft and attach a pusher propeller. The same engine drives the front wheels through a three-speed manual transmission. When operated as an aircraft, the road transmission is simply left in neutral (though backing up during taxiing is possible by using reverse gear.) On the road, the wings and tail unit were designed to be towed behind the vehicle. Aerocars can drive up to 60 miles per hour and have a top airspeed of 110 miles per hour.
Moller skycar
The Moller Sky car is a prototype personal VTOL (vertical take-off and landing) aircraft a "flying car" called a "Volantor" by its inventor Paul Moller, who has been attempting to develop such vehicles for forty years. The design calls for four fans encasing the propellers, which is safer to bystanders and more efficient at low speeds.
The craft said to be currently under development, the M400, is purported to ultimately transport four people; single-seat up to six-seat variations are also planned. It is described as a car since it is aimed at being a popular means of transport for anyone who can drive, incorporating automated flight controls. It is proposed that in a model for the general public, the driver may only input direction and speed. Piloting knowledge would be un-necessary; however, training will be required.
Further, developers claim that by using eight inexpensive Wankel rotary engines - compared to jet engines, the vehicle's price may eventually fall close to that of a luxury car ($100,000). The fuel consumption is claimed to be 20 miles per gallon similar to that of a big car but this has been calculated as unrealistic. According to the developers, operation of a Skycar will produce as much noise as traffic on a nearby freeway when taking off, and this will only last for a few seconds, because it climbs so quickly
Operation
A Skycar is not piloted like a traditional fixed wing airplane, and has only two hand-operated controls, which the pilot uses to inform the computer control system of his desired flight maneuvers. The Skycar's ducted fans deflect air vertically for takeoff and horizontally for forward flight
Rotapower engines
The engines to be used are being developed by a separate Moller company called Freedom Motors. They are Wankel engines they call "Rotapower" which have a direct drive to a propulsion fan. Each fan is contained in Kevlar-lined housings with intake screens to provide protection to bystanders. The Skycar has four engine nacelles, each with two computer-controlled Rotapower engines. All eight engines operate independently and, allegedly, will allow for a vertical controlled landing should any one fail.
The Rotapower Wankel engine would have the ability to operate on any fuel. Earlier Rotapower models used gasoline
Terrafugia-Transition
The Transition is a light sport, roadable aircraft under development by Terrafugia, a small start-up company based in Woburn, Massachusetts.
The Rotax 912S piston engine powered, carbon-fiber vehicle is planned to have a flight range of 400 nmi (460 mi; 740 km) using automotive grade unleaded gasoline and a cruising flight speed of 115 mph (100 kn; 185 km/h). It does not come with an autopilot.
On the highway, it can drive up to 65 miles per hour (105 km/h) to keep up with traffic. The Transition Proof of Concept's folded dimensions of 6 ft 9 in (2.1 m) high, 6 ft 8 in (2.0 m) wide and 18 ft 9 in (5.7 m) long are designed to fit within a standard household garage. When operated as a car, the engine powers the front wheel drive. In flight, the engine drives a pusher propeller. The Transition's layout, with folding wings, pusher propeller and twin tail, is similar to experimental aircraft N8072 built by Dr. Lewis A. Jackson in Xenia, Indiana during the 1960s.
The experimental Transition Proof of Concept's first flight was successful and took place under FAA supervision at Plattsburgh International Airport in upstate New York using FAA tail number N302TF. First customer delivery, as of March 2009, is planned for 2011
CONCLUSION
The flying car concepts will require some more time to be in reality.
Roadable aircrafts design and development are feasible.
Cost of roadable aircrafts play a vital role in their success.
The success of roadable aircrafts will end uncertain weather, rising costs, and ground transportation hassles on each end of the flight