Hybrid Cars

The hybrid version of automobiles offers the customer an interesting assortment of engine features that are supplemented with power options through the use of electrical motor and battery participation. These engine features are not available in every hybrid automobile currently being sold at automobile dealerships or through private sales in society today. The hybrid engines are equipped with gas powered, or dual powered engines, as well as an electrical motor that renders power support when needed. There is a heavy duty battery that serves as a source of power as well.

Within the hybrid breed of automobile engine varieties, there is a mild hybrid category and a full hybrid category. While each of these categories contain the same equipment, the performance of that installed equipment can cause your automobile to operate on entirely different principles. The mild hybrid category consists of a gas powered automobile engine that serves as the propulsion mechanism to move your automobile down the street.

Paired with this gas powered automobile engine is an electrical motor, as well as a heavy duty battery that are snuggly connected throughout the engine maze of pipes and mechanisms that when energized can provide propulsion to move your automobile forward. The hybrid car engine is the only source of propulsion power in the mild hybrid engine model, and the electrical motor remains in standby mode to provide spurts of energy and power to aid the gas powered engine in passing vehicles on a highway or wherever else a sudden surge of power will be of benefit.

The full hybrid category consists of a gas powered automobile engine that is considered the propulsion mechanism as well as an energy saving device. An electrical motor and a heavy duty battery are also part of this full hybrid engine power force. The gas powered engine works hand in hand with the electrical motor to provide the necessary boosts of energy to cause the car to propel through traffic. When the car is stopped at a traffic light, the gas powered engine will cease to operate, and the electrical motor will take over in providing propulsion power for the car to move from the site. Once the car achieves a good level of speed, the gas powered engine in the hybrid car will automatically engage and cause the car to continue down the street under gas engine power. The heavy duty battery is continually charged by the electrical motor at the same time.

The energy savings are accumulated during the different stops and starts that the vehicle might experience as the automobile moves toward its destination. Whenever the gas powered engine is not engaged there is a cost savings realized in its lax state of operation. The hybrid motor is quite capable of consuming energy and generating the right amount of power at the same time. These moments of non-engagement will save the consumer money in gas cost every time the automobile is driven down the road.

In conclusion, there exist more logical advantages of owning a hybrid car which is an unstoppable growing trend and unconfrontational facts.

Coffman engine starter

The Coffman engine starter (also known as a "shotgun starter") was a starting system used on many radial piston engines in aircraft and armored vehicles of the 1930s and 1940s. Most American military aircraft and tanks which used radial engines were equipped with this system. A derivation of the Coffman starter was also used on a number of jet engines, including those used on the Canberra B-57 light bomber.

The device used a blank gunpowder cartridge that, when fired, would cause the propeller to turn over and hopefully start the engine. The other systems used during the period were electric motors (such as those used in automobiles today) inertia starters (cranked either by hand or an electric motor) and compressed-air starters, which operate much like Coffman starters but are powered by pressurized tanks.

Shotgun starters are composed of a breech and a motor, which are connected by a metal line. The cartridge fits into the breech, and is triggered either electrically or mechanically. The expanding gases from the cartridge pressurize the line and cause the motor to spin and engage the starter ring on the engine, which is attached to the crankshaft.

The advantage of the cartridge system over electric starters is that the batteries of the time were weak and trouble-prone. Aircraft with electric motors often required the use of a battery cart and jumper cables, or large, heavy batteries carried in the plane. Inertia starters use a heavy wheel, usually made of brass, which is spun by a hand crank or electric motor, then the spinning wheel is made to engage the starter ring. The Coffman system weighs less.

The primary disadvantages of the shotgun starter are the need to keep a stock of cartridges, one of which is used for each attempt to start, and the short time that the motor is spun by each cartridge. Compressed-air starters, which use the same type of motor, are usually recharged by an engine-driven compressor, negating the need to carry cartridges. Hybrid systems can be made simply by adding a cartridge breech or an air tank to an existing system.

The Coffman starter was the most common brand of cartridge starters during the mid-1930s, and the name was used as a generic description. The starter became famous as a plot device in the movie "Flight of the Phoenix," when pilot James Stewart had a limited number of cartridges with which to start the makeshift aircraft's engine.

Some modern military diesels still use this device, but advances in battery technology have made shotgun starters obsolete for most uses.

Napier Nomad engine (aircraft engine)

The Nomad was a complex Diesel cycle aircraft engine from Napier & Son of the UK. The Nomad used a turbine to recover power from the exhaust of the otherwise conventional Diesel engine, resulting in a specific fuel consumption that remains unmatched by an aircraft engine 50 years later.


History

In 1945 the Air Ministry asked for proposals for a new 6,000 horsepower (4,500 kW) class engine with good economy. Curtiss-Wright was designing an engine of this sort of power known as the "turbo-compound", but Sir Harry Ricardo, one of Britain's great engine designers, suggested that the most economical combination would be a similar design using a diesel two-stroke in place of the Curtiss's petrol engine.

Prior to World War II Napier had licensed the Junkers Jumo 204 diesel design to set up production in the UK as the Napier Culverin, however the start of the war made the Sabre all-important and work on the Culverin was stopped. In response to the Air Ministry requirements they dusted off this work, combining two enlarged Culverins into an H-block similar to the Sabre, resulting in a massive 75 litre design. Markets for an engine of this size seem limited however, and instead they returned to the original Culverin-like horizontally opposed 12 cylinder design, resulting in the Nomad.

Design

The Nomad design was incredibly complex, essentially two engines in one. One was a supercharged Diesel similar to the Culverin. Below this was a complete turboprop engine, based on their Naiad design. The output of the turboprop was geared to a shaft running inside the Diesel's, driving the front propeller of a contra-rotating pair. As if that were not enough, during takeoff additional fuel was dumped into the rear turbine stage for additional power, and turned off once the plane was cruising.

The compressor and turbine assemblies of the Nomad 1 were tested during 1948, and the complete unit was run in October 1949. The prototype was installed in the nose of an Avro Lincoln bomber for testing, and first flew in 1950. In total the Nomad 1 ran for just over 1,000 hours, and proved to be rather temperamental, but when running properly it could produce 3000 hp (2,200 kW) and 320 lbf (1.4 kN) thrust. It had a specific fuel consumption (sfc) of 0.36 lb/(hp·h) (0.22 kg/(kW·h)).

Even before the Nomad 1 was running, its replacement, the Nomad 2, had already been designed. In this version an extra compressor stage was added, replacing the original supercharger. This stage was driven by an additional stage in the turbine, so the system was now more like a turbocharger and the compressed air for the Diesel was no longer "robbing" power. In addition the propeller shaft from the turbine was eliminated, and geared using a hydraulic clutch into the main shaft. The result was smaller and considerably simpler, a single engine driving a single propeller.

While the Nomad 2 was undergoing testing, a prototype Avro Shackleton was lent to Napier as a testbed. The engine proved bulky, like the Nomad 1 before it, and in the meantime several dummy engines were used on the Shackleton for various tests. By 1954 interest in the Nomad was dropping, and after the only other project based on it was cancelled, work on the engine was ended in April 1955.


Specifications (Nomad 2)

General characteristics

* Type: Twelve-cylinder liquid-cooled horizontally opposed Diesel combined with a turboprop aircraft engine
* Bore: 6 in (152 mm)
* Stroke: 7.375 in (187 mm)
* Displacement: 2,502 in³ (41 L)
* Dry weight: 3,580 lb (1,624 kg)

Components

* Cooling system: Liquid-cooled

Performance

* Power output: 3,135 ehp (2,338 kW) max take-off at 89 psia (614 kPa) including thrust power from the turbine
* Specific power: 1.25 ehp/in³ (57.0 kW/L)
* Compression ratio:
o Engine 8:1
o Turboprop compressor 8.25:1
* Specific fuel consumption: 0.345 lb/(ehp·h) (0.210 kg/(kW·h))
* Power-to-weight ratio: 0.88 ehp/lb (1.44 kW/kg)

Wright R-3350 engine

The R-3350 Duplex-Cyclone was one of the most powerful radial aircraft engines produced in the United States. It was a twin row, supercharged, air-cooled, radial engine with 18 cylinders. Power ranged from 2,200 to over 3,700 hp (1,640 to 2,760 kW), depending on the model. First developed prior to World War II, the R-3350's design required a long time to mature before finally being used to power the B-29 Superfortress. After the war, the engine had matured sufficiently to become a major civilian airliner design, notably in its Turbo-Compound forms.

In 1927 Wright Aeronautical introduced their famous Cyclone engine, which powered a number of designs in the 1930s. After merging with Curtiss to become Curtiss-Wright in 1929, an effort was started to redesign the engine to the 1,000 hp (750 kW) class. The new Wright R-1820 Cyclone 9 first ran successfully in 1935, and would become one of the most-used aircraft engines in the 1930s and WWII.

At about the same time Pratt & Whitney had started a development of their equally famous Wasp design into a larger and much more powerful two-row design that would easily compete with this larger Cyclone. In 1935 Wright decided to follow P&W's lead, and started to develop much larger engines based on the mechanicals of the Cyclone. The result were two designs with a somewhat shorter stroke, a 14 cylinder design that would evolve into the Wright R-2600, and a much larger 18 cylinder design that became the R-3350.

The first R-3350 was run in May 1937, but proved to be rather temperamental. Continued development was slow, both due to the complex nature of the engine, as well as the R-2600 receiving considerably more attention. The R-3350 didn't fly until 1941, after the prototype Douglas XB-19 had been re-designed from the Allison V-3420 to the R-3350.

Things changed dramatically in 1940 with the introduction of a new contract by the USAAC to develop a long-range bomber capable of flying from the US to Germany with a 2,000 lb (900 kg) bomb load. Although smaller than the Bomber D designs that led to the B-19, the new designs required roughly the same sort of power. When preliminary designs were returned in the summer of 1940, three of the four designs were based on the R-3350. Suddenly the engine was seen as the future of Army aviation, and serious efforts to get the design into production started.

By 1943 the ultimate development of the new bomber program, the B-29, was flying. However the engines remained temperamental, and showed an alarming tendency to overheat. A number of changes were introduced into the aircraft production line in order to provide more cooling at low speeds, and the planes were rushed to operate in the Pacific in 1944. This proved unwise, as the overheating problems were not completely solved, and the engines had a tendency to burst into flame after takeoff.

Early versions of the R-3350 were equipped with carburetors, which led to serious problems with inadequate fuel mixture distribution. Near the end of World War II, in late 1944, the system was changed to use direct fuel injection, where fuel was injected directly into the combustion chamber. This change improved engine reliability immediately. After the war the engine became a favourite of large aircraft of all designs, most notably the Lockheed Constellation and Douglas DC-7.

Following the war, in order to better serve the civilian market, the Turbo-Compound system was developed in order to deliver better "gas milage". In these versions of the engine, three separate power recovery turbines were attached to the exhaust piping of each group of 6 cylinders, using the power not to deliver additional boost as in a normal turbocharger, but geared directly to the engine crankshaft by fluid drives in order to deliver more power. This recovered about 20% of the heat of the exhaust, (something around 500 hp) which would otherwise be wasted. This is not without cost, however, for those devices are also nicknamed "Parts Recovery Turbines" (and worse), and were another source of failures.

By this point reliability had improved, with the mean time between overhauls at 3,500 hours, and specific fuel consumption on the order of 0.4 lb/hp.hour (243 g/kWh). Engines still in use are now limited to 52 inches of manifold pressure and 2,880 HP with 100 octane fuel (100LL) instead of the 59.5 inches and 3,400 HP possible with 115/145 fuels, which are no longer available.

Swashplate engine

The swashplate engine is a type of reciprocating engine that replaces the common crankshaft with a circular plate (the swashplate). Pistons press down on a circular plate in a circular sequence, forcing it to nutate around its center. This motion can be simulated by placing a CD on a ball bearing at its centre and pressing down at progressive places around its circumference. The plate, also known as a wobble plate, is typically geared to produce rotary motion. An alternate design replaces the plate with a sine-shaped cam, and is thus known as a cam engine.

The key advantage of the design is that the cylinders are arranged in parallel around the edge of the plate, and possibly on either side of it as well, and are aligned with the output shaft rather than at 90 degrees as in crankshaft engines. This results in a very compact, cylindrical engine. For this reason the design is also known as a barrel engine.

The arrangement also allows the compression ratio of the engine to be changed whilst running by adjusting the distance of the plate from the cylinders.


Applications

Swashplate engines are particularly interesting in the aircraft engine role, where their compact size is valuable. However, it appears no swashplate engine has ever been widely used in this role, although there have been numerous attempts to introduce one. This may not be any fault of the design, but the designers themselves. It appears that anyone working on these "oddball" engine designs seems to try to include every advanced feature known at the time, instead of using known technology where possible. The result are designs that never seem to mature.

A more successful application is in torpedoes, where the cylindrical shape is desirable. For example, the modern Mark 48 torpedo is powered by a swashplate engine.

Other applications include pneumatic and hydraulic motors and hydrostatic transmissions. Also some Stirling engines use swashplate arrangement.


History

The first known swashplate engine design was introduced by Statax-Motor of Zurich, Switzerland in 1913. Only a single prototype was produced, which is currently held in the Kensington Museum in London. In 1914 the company moved to London to become the Statax Engine Company and planned on introducting a series of rotary engines; a 3 cylinder of 10 hp, a 5 cyl of 40 hp, a 7 cyl of 80 hp, and a 10 cyl of 100 hp. It appears only the 40 hp design was ever produced, and installed in a Caudron G.II for the British 1914 Aerial Derby but was withdrawn before the flight. Hansen introduced an all-aluminum version of this design in 1922, but it is not clear if it was produced in any quantity. Much improved versions were introduced by Statax's German division in 1929, producing 42 hp in a new sleeve valve version known as the 29B. Greenwood and Raymond of San Francisco acquired the patent rights for the US, Canada, and Japan, and planned a 5 cylinder of 100 hp and a 9 cylinder of 350 hp.

Experimental barrel engines for aircraft use were built and tested by Mr J.O. Almen of Seattle, WA in the early 1920s, and by the mid-1920s the water-cooled Almen A-4 (18 cylinders, two groups of nine each horizontally opposed) had passed its United States Air Corps acceptance tests. It however never entered production, reportedly due to limited funds and the Air Corps' growing emphasis on air-cooled radial engines. The A-4 had much smaller frontal area than water-cooled engines of comparable power output, and thereby offered better streamlining possibilities. It was rated at 425 horsepower (317 kW), and weighed only 749 pounds (340 kg), thus giving a power/weight ratio of better than 1:2, a considerable design achievement at the time.

Indian motorcycle also introduced a swashplate engine, the Alfaro, in 1938. The Alfaro is a perfect example of the "put in everything" design, as it included a sleeve valve system based on a rotating cylinder head, a design that never entered production on any engine.

Stephen DuPont in 2006 wrote a small book, A 1911 Spanish Pilot and MIT Aeroengineer and his 1938 Aeroengine Upgraded for Today, ISBN 0-9777134-0-7, which details the development of a barrel engine for aircraft and contains a brief biography of its inventor, Heraclio Alfaro. DuPont was the son of the founder of the Indian motorcycle company; Alfaro was one of his professors at MIT. DuPont later worked further on developing the barrel engine, particlarly for a helicopter, the Doman.

Some small barrel engines were produced by the H.L.F. Trebert Engine Works of Rochester, New York for marine usage.

Perhaps the most refined of the designs was the British Wooler motorcycle engine of 1937. This design used two pistons per cylinder, moving in opposite directions (see the Junkers Jumo 205 for details). The connecting rods attached to a tilting plate through ball joints, and the plate in turn drove a swashplate for power.

More recently, Axial Vector Engine Company has been attempting to re-introduce the concept, although with limited success to date. Their engine, like many of the others on this list, also suffers from the "put in everything" problem, including piezoelectric valves and ignition, ceramic cylinder liners with no piston rings, and a variety of other advanced features.