Cars "catamarans"

“Simplicity is the hardest thing in the world; this is the extreme limit of experience and the last effort of a genius. "Leonardo da Vinci

Now often looking at the competition of solar vehicles in Australia, you can see the similarity of some machines, whose shape resembles a catamaran. What is the reason? What advantages does this form contain not only for solar machines?

About this, and much more will be this article.

First, a little theory.

The aerodynamic drag of a car can be reduced to three parameters.
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• The resistance of the frontal area of ​​the car.
• Resistance to form (air friction on the side surfaces of the car).
• Air swirling near the wheels and under the body.

In this case, only the 1st parameter will be considered. Since the second limit is a drop, it has already been partially considered in previous articles about tails on a car and the future amphibiousness of electric cars , while the third mainly depends on the width of the tire and the shape of the disk, and does not greatly affect the final result (compared to the first two).

Under the frontal understand the area F of the largest vertical cross section of the PBX, i.e. contour of its frontal projection. In approximate calculations, the real contour is simplified by straight line segments, which allow to represent the area as a set of simple geometric figures that do not require complex calculations.

In the case of a car with a dependent suspension, the frontal area is approximately equal to the sum of the 3 elementary areas, m2:



Where

- cab area by wings, m2;
- area of ​​the front axle beam, m2;
- open area of ​​the front wheels, m2.

Cars with independent suspension do not have a protruding beam under the car, and therefore the calculation becomes easier. The size of the frontal area depends on the shape of the body, and the smaller this area, the better you can "bring" the correct body shape in length to reduce Cx (form resistance).



Due to the “C” space, machines with a catamaran layout can reduce the total frontal area of ​​the car.

In pursuit of the sun and aerodynamics.

The principle of saving frontal area due to catamaran construction in recent years is clearly seen in the example of WSC single-seat sunkeepers.



These heliomobils, like many others not represented in the picture, use the same principle of form organization, resembling a catamaran. The need for this form - the desire to save energy at high speed.

Records of speed due to streamlined, however, were characteristic of this form of the body before.




So in 1949, the rider Piero Taruffi built two cars of the catamaran design at once - Tarf I, Tarf II. Outwardly, they almost did not differ.

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In 1949, Taruffi received a patent for his two-body record car in the United States. From 1951-1952, the car was built by Gilera using its most powerful motorcycle engine. He gave out 65 hp at 10,400 rpm

The engine was located in the right gondola, the pilot and control system - in the left. October 14, 1954 Taruffi set a world record for cars in the class up to 500 cm3 - 201 km / h.

But it was only the Tarf I. In parallel, with only a slight lag, Taruffi built the second car of a similar design - the Tarf II. On it was a powerful 1720-cc, 290-horsepower Maserati engine. Because of the very small cockpit, there was no room for the steering wheel in the car, and the control was carried out by two levers, right and left, located at the pilot's arms down. The car had the reverse layout of the first generation - the driver was sitting on the right, the engine was on the left.

Amazingly, Tarf II, which began to be built later by Tarf I, was finished earlier. The first record - the average speed at a distance of 50 miles, 231.744 km / h - Taruffi put it on January 15, 1952.

From single to 2-4 local land catamarans.

The 1967 auto show was rich in surprises, and one of them was the strange concept of OSI Silver Fox.

At first glance, its design was irrational - after all, the body clearly needed rigidity in the central part so that it would not sink under the influence of external forces. Even the passenger and the driver were sitting at a great distance from each other.

Nevertheless, the Silver Fox's two-piping scheme had one big advantage - it allowed to pass under the car exactly the volume of air that was required on a particular track for sustainable movement. Simply put, the body allowed to adjust the level of downforce. In order for the volume of air masses to be passed it was possible to regulate, Silver Fox had three jumper wing covers: the rear spoiler was stationary, the central one was adaptive, changing the angle of attack depending on the moment of inertia, and the front one was mechanically adjustable, .

As a result, the concept, equipped with a 1-liter 4-cylinder Alpine engine and having a curb weight of 500 kilograms, could accelerate to 250 kilometers per hour! At the same time, fuel consumption was not excessive, which was also important for participating in daily marathons for which the car was being prepared.

Other interesting features of OSI Silver Fox include the original “Leman” steering position (on the right side) and the peculiar balancing between the sides - the engine located in the left pontoon was balanced by the driver and the spare wheel on the right.

The shape of the car, which resembles the letter “P” in profile, has not been forgotten in our time. The PrISUm research laboratory, consisting of students at the University of Iowa, built a prototype Penumbra P14 “solar” electric vehicle that can be operated on ordinary roads.



This car still has the potential to reduce drag, if the developers apply the idea of ​​“humps” from the Dodge Viper on the roof.


Structurally, the body is very simple, glazing and the wheels are the most ordinary, even there is a radio tape recorder like a regular car. The only obvious difference is the solar panels on the roof and the hood. According to the authors of the project, this car should be a certain transitional stage between a specialized solar car and a conventional electric car for family use. The project sponsors include Siemens and Boeing, which can be considered not at all superfluous, since the cost of development and construction is estimated at no less than $ 750,000. The range of the Penumbra is 322 km. The body of this car is made of composite materials based on carbon fibers, like most solar electric cars, which allows you to count on a good strength-to-weight ratio.

In addition to Penumbra, there are 2 more models of sunflowers having a similar shape.



Stella lux



Ardingly solar car

These electric cars are worse adapted to normal user use, but have better performance.

Sometimes a minus to a minus gives a plus ...

Danish company RUF International is actively working on a project combining personal and public transport. The project site contains various versions of the concept of a new monorail transport.

According to the project, small sections of the road can be overcome on ordinary roads, but generally more economical movement on rails of the original construction is planned.



It is planned to make such a hybrid vehicle fully automatic, but if necessary, the driver will still be able to drive the car himself. True speed of movement on rails will have a limit - no more than 120 km / h, which can not be disabled.

According to the RUF International project, the road network for such cars will consist of 25-kilometer rail sections with special “crossings” every five kilometers so that some drivers can join the movement, while others turn or move off the rails. The maximum speed between the "transitions" (150 km / h) when approaching interchanges will automatically be reduced to 30 km / h.

It is planned that U-shaped electric cars will receive energy when driving on a monorail wirelessly, and this should be enough for a short movement on ordinary roads. Due to this hybridization, it will be possible to reduce the weight and dimensions of the batteries of electric vehicles, which will positively affect the other characteristics of this automated personal transport.

Considered two options for the use of such electric vehicles.

1. Personal electric car with autopilot level 5.
2. Carsharing based on a user's personal card.

The RAF system is designed with a high level of versatility and therefore it is planned that machines of different classes will be able to use it. Trucks, Buses and cars in this case simply have to be adapted to travel on rails due to the V-shaped channel passing along the bottom of the car body.

The "cut" runs in the middle and inside divides the interior into two parts. The developers propose to use the "hill" as an armrest or "space for a child."
The monorail system is designed for large cities, but the authors of the project have not forgotten about the residents of the suburban area: there is a hybrid transport with electric and fuel engines.

The main advantage of the introduction of the RUF hybrid transport system will be its environmental component, which will be expressed in reducing the energy costs of moving vehicles and the cost of maintaining roads.


For example, public commuter transport, called Maxi-RUF, is a bus that can carry ten passengers, not counting the driver.

The company has been working on its concept since 1988. RUF International has 16 sponsors, including the Danish branch of Siemens and the Danish Ministry of Energy and the Environment.

At first glance, the concept of the Danes is questionable, although this project actually has very ancient roots. So in the 19th century, the French engineer Charles Larting developed a similar-looking rail for the movement of locomotives.

This rail transport was named Monorail system Lartigue.




This is one of the first monorails in general, and at the same time one of the first monorails that had practical application. One of the most famous roads on which it was used was called the Listowel and Ballybunion Railway.

In cross section, the path was similar to the letter “A” about a meter high. Above went the main (carrying) rail, two sides of the guide rails were running along the bottom. This path was installed on the ground on the sleepers. Sections in the shape of the letter “A” were installed at a distance of about a meter from each other. Since the length of the “legs” of the sections can be arbitrary, there is no need to level the ground under the tracks during construction!

In addition to the main wheels, supported on the upper rail, locomotives and wagons had supporting wheels, which supported the guide rails and protected the train from overturning. The Laring system has high manufacturability, it is easy to disassemble and move it from place to place.

The most important factor in the operation of such a road is to ensure the balance of the train. Before departure, the conductor ensured that the number of passengers in half of the car on one side of the rail corresponded to the number of passengers in half of the car on the other side of the rail. The RUF project in this case, the same will not pass this "obstacle" in the implementation, but cars and buses by weight certainly do not go to any comparison with the trains.

Amphibious "catamarans"

Is a catamaran an original water transport? So really there were no amphibious hybrids of this design?

Were! And especially original homemade products can be found in the period of the USSR.





Universal catamaran of the USSR on the water - ice - land. A note about him was in the magazine Technique-Youth 1962 number №4, and in its full form looks like.

"How to be lovers of water sports and long-distance tourism, living far from rivers and reservoirs? Where to store motor boats and boats, how to deliver them to the water, where to put the wheelsets and other vehicles necessary for transportation and unnecessary, when the journey begins on the water?

Reflecting on these issues, I was convinced that the best solution was an amphibious all-terrain vehicle that could move on the ground on wheels, float on water, and in winter, ski on snow. On such an all-terrain vehicle it costs nothing tens of kilometers along the road. Reaching the reservoir, it is enough to remove the wheels and continue the journey on the water.

In order to give amphibians the greatest possible stability, I decided to make it in the form of a catamaran. To do this, it was necessary to make two identical streamlined shells. I installed 12 frames of 10-millimeter plywood on the building berth, punched 12 outer stringers of 8x18 mm pine and 6 inner ones into them. After This, the shell of each shell is pasted over with one layer of birch veneer.

Then from epoxy resins is prepared composition for pasting frameworks of coarse calico and fiberglass: (EDF-1 - 60 parts, EDF-3 - 40 parts; dibutyl phthalate - 13 - 15 parts, poly-ethylene polyomyl - 16-18 parts). To avoid the composition on the hands, face, necessary rubber gloves and deaf overalls with ties on the cuffs. Epoxy resins are poured into a white tin bath and heated to 80-90 ° C.
After that, the bath is placed on the scales and a plasticizer (dibutyl phthalate) is added to it. The mixture is thoroughly mixed and simultaneously cooled to 24 ° C. Now you need to add a hardener (polyethylene polyol) to the cooled mixture, mixing it strongly to avoid clumping. All this is uniformly applied to the surface of the shell, and the temperature should be around 24-30 ° C, because otherwise the mixture quickly thickens and does not penetrate well into the weaving of the fabric. A coarse calico or fiberglass is stretched onto the coating layer and is carefully rolled with spatulas. On birch veneer, one layer of fiberglass and one layer of calico are applied. Only in the places of future openings for connecting frames additional transverse belts of 4 layers of fiberglass are glued, the width of each is 20 cm.

After the irregularities are smoothed and cleaned, each shell is pasted over entirely with one layer of fiberglass, and an additional strip is glued to the bottom.

Then the two streamlined shells are interconnected by four welded detachable frames of thin-walled chromosile pipes. On the protruding ends of the two front frames are detachable forks, to which either the wheels from the Tula-200 scooter, or hydrofoils, or skis are attached.

The two front wheels are spherical and steering. The third wheel, reinforced between the two rear frames on the trapezoidal farm, is the leading one. It is planned to install a motor with a propeller for movement in water or snow.

Currently, the front-wheel brackets and the rear wheel truss are removed for water navigation. In place of the farm is mounted bracket with a movable carriage for installation of the steering engine "Moscow".

In the summer of 1961 began trial tests of the catamaran in the water. With the engine "Moscow" in 10 liters. with. and 4 passengers catamaran freely bypassed duralumin type "Mir" with the same engine and 2-3 passengers. At full throttle, the catamaran went into gliding mode, two whiskers of whiskers appeared in front, and between the “tails” of the shells, two small fan-shaped, diverging plumes of water. Whirlpools, characteristic of motor boats with a flat stern, was not observed.

The catamaran proved to be very stable due to a kind of “self-regulation” due to the pressure of the diverging jet of water on the tail parts of the shells. Draft at a load of 800 kg was only 120 mm. The weight of the catamaran with the motor "Moscow" is about 120 kg. Controlling the rotation of the motor "Moscow" made in the rear left cab. The gas is regulated by turning the flexible hose.

When testing was revealed stiffness and sufficient mechanical strength of the shells. It can be assumed that in terms of stability and speed, the catamaran will not yield to the existing types of motorboats. If necessary, the catamaran shell can be separated for transport by road or by rail.

In the future, tests will be conducted with hydrofoils, skis, a 30-horsepower M-61 engine and a hydraulic drive to the rear wheel.

When building a catamaran, I used experienced epoxy resins of the Nizhne-Ta-Gilsky plastics plant. Despite the imperfection of the manual manufacture of shells, they are well justified by mechanical strength and water resistance. Although these resins are dark in color, they can be colored as needed. When building a catamaran, the Ural Forestry Institute provided me some help, and members of the Sverdlovsk marine club DOSAAF helped me in the tests.

B. ROAD ENGINEER.

It’s a pity the author didn’t think about the air variant of using his “all-terrain vehicle-catamaran”, but already thought about the catamaran-aircraft.

Flying "catamarans"

Carplane GmbH has created a specific flying car.

This flying machine has not one, but two whole fuselages, and has the ability to surmount from car to plane. How does this happen? When Carplane moves on the ground, the wings and propeller are folded in the middle of the car, just between two single fuselages. If the flying machine needs to take off, then these wings are quickly deployed with the help of electric drives, and the rear part of a flying car with two keels is also extended by more than two meters.

Carplane has an engine of 150 horsepower, the highway can accelerate to a maximum of 176 km per hour, and its maximum speed in the air is 222 km per hour. The cruising speed of a flying carplane car is 200 km per hour, and if you fly it with this speed, then a tank of gas for 100 liters is enough for just 830 kilometers.

Carplane is not the only catamaran of its kind and there is an even more sophisticated device in terms of aerodynamics.




The BiPod is an airplane vehicle capable of traveling on ordinary roads. The body of the machine is divided into two volumes. In each of the "floats" there is a place for the driver and a hybrid drive, and the wings are able to fold into the opening between the hulls.

The device has a serial hybrid drive. So in each fuselage there is a 450-cc internal combustion engine rotating the generator. In the nose are lithium batteries, and in the tail - 15-kilowatt electric motors drive the rear wheels. Driving wheels in front.

PS: The story often moves in a circle, and perhaps the transition to a split form of cars can solve not only the problems of energy saving, but also the safety of pedestrians, stability in turns, and even survival during side impact. All this is so far only concepts of ideas at the level of theory, and some analogies with already tested technologies, but as with the idea of ​​RUF there is basically nothing complicated here - the question is only in the necessity of such modifications.