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Moller Sky Car on Ebay Jan 31st
Submitted by SuperUser on Saturday, January 25, 2003 - 4:11pm

vo - lan - tor (vo-lan'ter) n. A vertical takeoff and landing aircraft that is capable of flying in a quick, nimble, and agile manner. --intr. & tr.v. -tored, -toring, tors. To go or carry by volantor. [Lat. volare, to fly. Fr. volant, to move in a nimble and agile manner ] The Skycar volantor developed by Moller International is capable of vertical take-off and landing (VTOL) much as a helicopter and flies from point of departure to destination much like an airplane. However, the Skycar volantor is uniquely qualified to travel short distances on the ground as an automobile as well. All this and incredibly, its easy to fly! Actually a computer does the flying. The pilot need only move the controls in the direction he wants to go so that little skill is required. (Still for the time being, the operator will need to have a private pilot's license until the ease of operation and safety are thoroughly demonstrated.) The Moller Skycar is a volantor capable of these remarkable achievements through the use of an arrangement (array - collection - grouping) of proprietary technologies. Favorable power to weight ratio is the basic qualification for VTOL. However, in order to create a safe, environmentally responsible and economically feasible method of transportation Moller International had to take into consideration a number of components including airframe and engines. The Airframe A VTOL aircraft with its larger installed power must be aerodynamically efficient at high cruise speeds if it is to use that installed power efficiently. Also, if the airframe of the volantor is not appropriately aerodynamic, fuel consumption increases and its maximum travel distance (range) becomes unacceptable. The ideal airframe must also be lightweight so the craft can obtain a favorable power to weight ratio. Lastly, it must be strong for stabilization and safety. The determination of aerodynamic efficiency comes down to the following:

  1. When the aircraft is moving at high speed, does the propulsive air move efficiently through the propulsion or thrust system?
  2. Does the aircraft have a small frontal area?
  3. Does the aircraft have a small wetted area (surface area in contact with the airstream)?
  4. Is the vehicle sufficiently streamlined to ensure that its aerodynamic surfaces are free from airflow separation and therefore present a clean aerodynamic design?
  5. Does the configuration achieve a good lift/drag ratio at high cruise speeds?
Some light planes built today, particularly those in the experimental or homebuilt category do an excellent job satisfying the above conditions. A measure of aerodynamic performance is the passenger transport efficiency (PTE) as measured by: PTE = (Passenger Miles / Gallon) A few four-seat aircraft have a PTE near 70 at 250 MPH although they will generally have a fairly high landing speed without STOL (Short Takeoff and Landing) provisions (flaps, slats, etc.). The key to a successful high-speed design with a high PTE is finding a way to simultaneously satisfy the five stated aerodynamic requirements. For example, a long, very narrow aircraft could certainly be streamlined and have a small frontal area, but might have an excessive wetted area.
  • An efficient VTOL aircraft requires the propulsive airflow to move almost horizontally through the system during cruise because even a modest bending of the flow can introduce a substantial drag due to momentum losses.
  • A frontal area under 25 ft2 is realistic for a VTOL aircraft carrying up to four passengers.
  • A wetted area to frontal area ratio under 15 is achievable with an efficient airframe design.
  • The drag coefficient based on wetted area (CDwet) is a good measure of the aircraft's freedom from airflow separation. A well-designed aircraft should achieve CDwet of .005 at cruise while a state-of-the-art design arrived at after extensive wind tunnel testing could have a CDwet 250 MPH).
The Skycar volantor's composite airframe is constructed mostly of FRP (fiber reinforced plastic) which enables it to be both lightweight and strong. We have our own 250 mph wind tunnel in which we have performed over 1000 hours of detailed flight testing using both powered and un-powered models to ensure that we have chosen an optimum design. The Engine As seen from the example above, VTOL aircraft requires a great deal of power to obtain lift-off and perform a safe landing. Since the engine must lift its own weight along with the weight of the craft it must be lightweight. Economy is another area that requires much attention. Purchase price, operating costs, and maintenance costs are all factors which, if too high, can make the engine impractical. Lastly, to be truly efficient, an engine must be environmentally friendly. Ideally, clean burning engines capable of using the most readily available fuels would provide the best option. The need for a moderately high disc loading results in a relatively high installed power in order to hover. For the installed powerplant weight not to become excessive, the engines must be light for their power output. The key element in determining the VTOL aircraft cost may then become the powerplant. If, for example, one uses 200 lb/ft< disc loading, it can be shown that: (Installed Horsepower / Gross Vehicle Weight) ~ 0.5 In this case, a VTOL aircraft with a modest payload requires installed power in the 1000 HP range and an engine HP to weight ratio near 2. A turbine can meet this weight requirement; however, a small 100 HP turbo-shaft can cost $100,000, while a single 1000 HP turbo-shaft can cost $300,000. The smaller turbo-shaft gives a poor specific fuel consumption, while the single engine provides no back up. Any design using turbo-fan engines will expect even higher engine costs. A turbo-fan using disc loading like the Harrier generates only one half pound of lift for every horsepower. Hence, the Harrier requires approximately 40,000 HP with little payload capability in the VTOL mode. To meet the 2 HP/lb requirement in a small fuel-efficient form, only two engine alternatives appear to be possible at an economical cost:
  • A turbo-charged or super-charged fuel injected 2-cycle engine. This engine would need to be developed.
  • A rotary engine that employs aluminum housings, peripheral porting and an air-cooled rotor. Engines of this design are in existence.
Moller rotary engines were developed from technology obtained from Outboard Marine Corporation (OMC) and are of the Wankel-Type. During each rotation of the rotor a four-stroke spark ignition combustion process occurs in each of the three pockets of a triangular rotor. After one full rotation of the rotor the engine has completed the four-stroke process three times. They therefore provide a high power-to-weight ratio at a reasonable cost and are very small for their power output. The 150 HP model used in the M400 can be easily carried by one person. Eight Rotapower engines are used in the production model volantor. Wankel-type rotary engines in general are very reliable as a result of their simplicity. The number of moving parts in a Moller rotary engine (dual-rotor) is approximately seven percent of those in a four-cylinder piston engine. The rotapower engine is also multi-fuel capable. Moller rotary engines in the volantor are typically configured to run on unleaded gasoline however, we have recently demonstrated the engine's ability to run on diesel to the Army and on Natural Gas to another organization.

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subject:
No title supplied
author:
No Rotor
date:
December 31, 1969 - 4:00pm
This thing has been trying to get off the ground for 10+ years. I'm glad to see that they are going to try to put in on Ebay, but when will real production start, and what will be the final price?
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subject:
No title supplied
author:
No Rotor
date:
December 31, 1969 - 4:00pm
And, can we use these rotaries in our rx7s?
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