DE10060548A1 - Exhaust gas diffuser for gas-turbine-powered aircraft - Google Patents

Abstract

The exhaust gas diffuser is built in between the rear end of the turbine and the front part of the main wing. It consists of a cylindrical part and a fin which has guide sheets, a distributor turning on pivots, a cone and flaps turning on other pivots. It may be possible to turn the lower side of the rear end of the fin by means of a lever.

Description

The present patent deals with the use of exhaust gas properties of gas turbine aircraft to generate additional lift, because buoyancy means security and because it is obtained from energy the buoyancy is becoming more and more expensive.

From the enthalpy-entropy diagram (gas turbine cycle - sketch 1) shows that at the end of the nozzle there is always an unused pressure potential in the Exhaust jet remains.

On the other hand, a gas turbine can only generate thrust if the The speed of the escaping gases is greater than that of the entering air (Basic Principle).

It can be seen from these two findings that the exhaust gases are one Aircraft gas turbine at the end of the nozzle over a thrust rest and a large one Speed.

It is known from gas mechanics that the thrust of gases in a diffuser changes their speed (increases). Changes in the speed of the air (gases) around the wings of an aircraft, negative or positive pressure, which gives the machine an (additional) lift or downforce. In order to put the exhaust gases of a gas turbine into the service of an aircraft, they first have to

• a) collected,
• b) bundled and
• c) brought to where they are used

The diffuser of the invention, a special construction made of aluminum alloy, sketch 2 , item 1, takes on these three fundamental tasks.

To collect the escaping gases and direct them to the wings, the diffuser is placed between the back of the gas turbine and the front of the wing of an aircraft, sketch 2 .

Viewed from the outside, the diffuser consists of the cylindrical part 2 , in which the turbine exhaust gases enter and the fin, part 3 , from the end of which the exhaust gases are conducted around the wings.

Sketch 3 shows the internal structure and equipment of the diffuser, which are required to fulfill the various tasks that it is supposed to perform.

The cylindrical part 2 of the diffuser consists of 2 (or 3) interlocking cylinders (sketch 4. ), That is, the fixed cylinder 4 and the outer movable cylinders 5 and 6. , Whose inner surfaces are covered with sound-absorbing material 7 , the free end of the outer cylinder receives a funnel-shaped shape. The axially movable cylinders 5 and 6 are, with the help of the slide 9 , the teeth 10 and the endless screw 11 of the bracket 12 , brought between the fixed cylinder 4 of the diffuser and the rear part of the turbine in the required position. The fin (sketch 3 ) consists of the surfaces 14 (above) and 15 (below) divided into rectangular shafts by the guide surface 16 , which lead the exhaust gases to the wing. The distributor 17 , which rotates around the hinges 18 , regulates the volume of the exhaust gases. 17 and 18 are attached to the cone 19 , which in turn is attached to the front side of the wing. The flaps 22 and 23 , which rotate about the hinges 20 and 21 , regulate the speed of the gases flowing onto the wing.

Sketch 3 (item c) shows the lever 31 , which rotates about the axis 32 , presses the lower side of the mixture outlet channel between the hinges 34 and 21 down with the printer 33 . The flow is deflected by the appropriate adjustment of the flap 23 . This creates a strong pressure on the lower wing, which combined with a simultaneous vacuum on the upper wing maximizes the rise in lift.

Sketches 5 and 6 show the suspension of the turbine on the machine by the carrier 41 , the diffuser on the turbine by the bracket 12 and the separator plate 42 of the diffuser flow.

Because the velocity of the gases above the wing is higher than usual, to avoid a break in the flow to the flaps (sketch 7 , item c), in the area of the diffuser flow width over the rear end of the wing 24 (sketch 8 ) and the flap 25 has a flow deflection guide 28 attached in the casing 29 (see also sketch 9 , items a and b), which ensure the continuity of the flow at all positions of the flaps (sketch 9 items c and d) or the failure of Turbulence and thus work optimally as an additional buoyancy amplifier.

function

The high exit velocity of the exhaust gases from the turbine creates one Suction in the surrounding air, a kind of co-current effect, which sweeps it away, also due to the funnel-shaped head of the diffuser, so that in the A mixture of exhaust gases and air flows into the diffuser, initially a mixture called.  

The axial fan, which is driven by the residual thrust of the flow, makes one out of the cylindrical turbulent flow of the mixture uniform, a homogenized mixture, which as a flat, box-shaped laminar flow leaves the diffuser and onto the wing of the machine flows continuously.

With the help of the distributor 17 , the volume of the mixture is directed to the desired outlet side (upper or lower) of the wing. The flaps 22 and 23 regulate the exit velocity of the mixture by the size of their opening. The mixture flows over the wings at a much higher speed than the speed of the surrounding air, which is at most equal to the speed of the machine. The speed of the mixture is adjustable, self-generating and continuous. There is therefore no possibility of interrupting the flow over the wings at any phase of the flight.

The distributor 17 and the flaps 22 and 23 can dose the volume and the speed of the mixture over the wings so that on each side of the wing there is the desired effect, which in most cases is the rapid increase in lift.

The diffuser creates its own adjustable buoyancy regardless of that Angle of attack of the machine.

Economy and safety of the diffuser

The diffuser creates and delivers lift to the wing of the machine as soon as the engines are in operation. A low speed (V _1-Diff <V ₁ ) is required to lift off the machine, which already has sufficient lift on the wing when it rolls onto the runway. This means:

• - Slip savings (energy)
• - small load (fatigue) of the structural associations of the machine
• - lower noise generation (intensity and duration)
• - Start with large buoyancy reserves (safety)
• - Start interruption without problems due to the low V ₁ speed and the unused runway

Sketch 10 shows the start of machines with and without a diffuser at the same angle of attack. Due to the additional buoyancy A _{D of} the diffuser, the diffuser machine rises faster to the optimal flight altitude and manages the flight route AB (sketch 11 ) faster at optimal flight speed without extensive nuisance to the airport and the surrounding area due to the flat climb flight than conventional machines. Steep flights are known to be expensive and there are limits to the angle of attack, the flow breaking off, the formation of turbulence with loss of lift. The same procedure in reverse order applies when leaving the flight altitude and when approaching or landing. The additional buoyancy A _{D of} the diffuser is much more frequent when landing and of much greater importance than when starting. A _D enables the machine to land at a lower speed, which is often of immense importance for safety. As soon as the machine touches down on the runway, a switch is made to negative buoyancy, ie the machine exerts a large, adjustable pressure downwards, thereby producing a braking effect, which quickly brings it to a standstill.

From sketch 11 it can be seen that the shorter the distance AB, the greater the economic advantages of taking off / landing with diffuser machines.

Most (about 80% statistically) of the aircraft disasters happen at Taking off and landing. The small take-off / landing speed made possible by the additional lift of the diffuser that such disasters are reduced become.

Aerodynamic quality / gliding flight

The diffuser improves the aerodynamic quality (glide ratio) of the machine, as is known

(where A = buoyancy = distance)

Since A _D <A, the glide distance increases and the machine gets a longer glide flight by reducing the glide angle.

Buoyancy in the case of failed engines of diffuser machines takes place by switching on the axial fan, with power supply from the APU. The blower pushes the suctioned atmospheric air through the shafts of the Diffuser on the full width of the fins, which are even and laminar on the The wing flows and thereby generates the optimal lift.

Flights in extremely bad weather conditions

The diffuser machines have two important properties that enable them to fly relatively less easily in bad weather conditions:

• 1. a large part of the wings flies into its own, self-generated and evenly spread continuous air (mixture) flow. Thereby the influence of turbulence and strong gusts of wind is reduced.
• 2. the rapid generation of large (additional) buoyancy.

This feature, along with 1), helps the machine in the instant Recovery of the lost flight altitude (fall) when flying through air holes

Greater maneuverability of the aircraft

The ability of the diffuser on either side of a wing to lift or descend Generating propulsion quickly increases the performance of the elevator and ailerons beyond their capacity and thereby the maneuverability of the machine in total velvet. The diffuser can replace the elevator and ailerons in an emergency. The maneuverability of the machines is becoming increasingly important due to the constant growing takeoffs and landings at all major airports from where "almost" clashes are increasingly reported.

noise reduction

The problem of noise pollution at airports and their surroundings is growing constantly by the ever increasing number of machines.

The diffuser, which takes the steep flight of the machine when starting (and landing) allows easy, the duration of noise pollution for the airport and its Shorten the environment.

The main cause of the noise source, however, is known to be the intensive phase "Mixing" the exhaust gas jet with the surrounding air of the atmosphere, equal after the exhaust gases exit the turbine.

For these reasons, the "mixing" process does not take place outdoors, but within a room covered with sound-absorbing material, which can be moved up to the exhaust gas outlet of the turbine. This space is provided by cylinders 6 and 5 of sketch 4 . In the mixing process, the residual energy of the exhaust gas jet is converted into kinetic energy, which is absolutely controllable by the diffuser and is therefore useful.

This postponement of the "blending" process becomes a considerable one Noise reduction expected.

This process should be used during takeoff and landing.

Claims (7)

1. Exhaust gas turbine-powered aircraft (sketch 2 ), characterized in that between the rear end of the turbine and the front part of the wing of the diffuser 1 of the invention is permanently installed, consisting of the cylindrical part 2 and the fin 3 , which is equipped (sketch 3 ) with the guide plates 16 , the distributor 17 , which is rotatable about the hinges 18 , the cone 19 and the flaps 22 and 23 , which are rotatable about the hinges 20 and 21 . 2. Exhaust gas turbine-powered aircraft as characterized in that the lower side of the rear end of the fin (sketch 3 , c) by the lever H and the push button D around the axis O downward chen Chen rotated around the hinges M. , 3. Exhaust gas turbine driven aircraft as in claims 1 and 2 characterized in that the cylindrical part of the diffuser consists of the in-going cylinders (Skitte 4 ) 4 , 5 and 6 , the cylinder 5 and 6 from the inside with sound-absorbing materials 7 are coated, the free end of the cylinder 6 having a funnel-shaped shape 8 and the axial blower 13 being permanently installed at the inner end of the cylinder 4 . 4. exhaust gas turbine-powered aircraft as characterized in that the cylindrical part of the diffuser is attached to the turbine by the bracket 12 (sketch 4 ) on which the endless screw 11 is installed, which by the gear 10th ensures the axial movement of the slide 9 . 5. exhaust gas turbine driven aircraft as in claims 1 to 4, characterized in that the turbine (sketch 5 and 6 ) is fixed by the beam 41 on the fuselage of the aircraft. 6. exhaust gas turbine driven aircraft as in claims 1 to 5, characterized in that on the upper wings of the machine (sketch 5 and 6 ) the aluminum rails 42 are firmly installed in order to separate the flow of the diffuser from the rest of the flow of the wings , 7. exhaust gas turbine driven aircraft as in claims 1 to 6, characterized in that on the upper sides of the wings (sketch 8 and 9 ) and in the width of the diffuser flow, the flow deflection guide 29 is guided in the shell 28 , which by the Supports 26 and 27 is attached to the wings 24 and flaps.