HS code-driven letter of credit checks

List of the catalog of this article:

• 1,HS code-driven letter of credit checks working principle of aircraft engine
• 2, Aviation launch What are the advantages and disadvantages of turbojet, turbofan and turboprop engine
• 3, What engines are commonly used in civil airliners nowadays?
• 4, What is the difference between an aircraft engine and a turbine engine?
• 5, What aircraft is the turboprop engine for

The working principle of aircraft engine

There are two common classification principles of aircraft engines: the principle of whether the air participates in the engine work and the principle that the engine generates propulsion power.

The principle of the aircraft engine is to inhale air, compress the air and mix it with fuel to produce high-temperature and high-pressure gas, and then convert the energy of gas into mechanical energy through the turbine to drive the aircraft forward. Specifically, aircraft engines are usually composed of intake ducts, compressors, combustion chambers, turbines and nozzles.

The working principle of the fighter turbofan jet engine The structure of the modern turbojet engine is composed of an intake duct, compressor, combustion chamber, turbine and tail nozzle. There is also a force combustion chamber between the turbine and tail nozzle of the fighter.

What are the advantages and disadvantages of turbojet, turbofan and turboprop engine in aviation engine

Advantages of turbofan engine: large thrust, high propulsion efficiency, low noise, low fuel consumption, The plane has a long range. Disadvantages: The fan has a large diameter and a large windward area, so the resistance is large, the engine structure is complex, and the design is difficult.

Vortex spray: the most basic, simple structure, small diameter, so the wind resistance is small. A large amount of heat is discharged from the tail nozzle if it is not used, which is fuel-consuming.Turboprop: Between the turboproper and the piston propeller, a free turbine is added after the turbine to drive the propeller to rotate, improve fuel utilization and save fuel.

Compared with the turbofan engine, the fuel economy of the turbojet engine is worse, but the high-speed performance is better than that of the turbofan, especially the high-speed performance. Basic parameters thrust-to-weight ratio: Thrust to weight ratio represents the ratio of engine thrust to the weight of the engine itself. The larger the performance, the better.

What engines are commonly used in civil airliners nowadays?

1. The turbine fan engine is the mainstream engine of civil aviation passenger aircraft at present. It generally adopts a high duct ratio (the ratio of the air flow of the connotation channel to the outer culvert) engine. Compared with the turbojet engine, this engine is more fuel-efficient. The propulsion efficiency in the subsonic state is higher than that of the turbojet engine, and the noise is low.

2. Civil airliners generally use turbofan engines, and fighter jets generally use turbojet engines. Both are jet engines. Among the two engines, turbine refers to the use of high-pressure gas to drive the turbine and then drive the compressor.

3. Piston propeller engine: that is, the engine of old-fashioned aircraft before World War II, relying on the piston to drive the propeller to rotate through the crankshaft, and it cannot reach supersonic speed. It is basically extinct now. It is only used by a few small civilian aircraft. This kind of engine uses aviation gasoline at the lowest cost.

4. Yes, Chinese passenger aircraft are generally imported from abroad, and now there are very few turbine jet engines. At present, it is known that the J8 is still in use.

5. The vortex fan now used in f22 in the United States is now capable of supersonic cruising without force.

6. Once the A380 is put into service, it will become the civil aircraft with the largest payload in aviation history. The original range of the model is 7,650 nautical miles to 8,000 nautical miles, and the range is planned to be expanded in the future, so it needs a reliable new thrust class (about 310 to 340 kN) aviation engine. .

What is the difference between an aircraft engine and a turbine engine?

Usually, the engine is naturally aspirated by NA, and there is an air filter in front of the air intake. After changing the turbocharge, a larger flow of air flow is required, so a larger caliber air filter is needed, which is the so-called winter mushroom head.

Different characteristics. Turbine engines are usually used in aerospace and navigation, and piston engines are usually used in the ground and navigation. Piston engines are characterized by high thermal efficiency (rely to turbine engines), large output torque and fast start-up, so they are suitable for ground.

The structure of the turbine/rocket engine is similar to that of the turbine/stamping jet engine. An important difference is that it prepares its own oxygen for combustion.This engine has a multi-stage turbine-driven low-pressure compressor, and the power that drives the turbine is generated by burning fuel and liquid oxygen in a rocket combustion chamber.

Different definitions (1) A turbojet engine is a kind of turbine engine. It is characterized by completely relying on gas flow to generate thrust. It is usually used as the power of high-speed aircraft, but the fuel consumption is higher than that of the turbine fan engine.

Car engines only increase the air intake, which in turn increases efficiency. The engine is still a piston.

What aircraft is the turboprop engine suitable for

Aircraft powered by turboprop engine. The fuel consumption rate is low. It is suitable for medium-speed (below 800 to 900 km/h) long-distance flight. Passenger aircraft, transport aircraft, coastal patrol aircraft and anti-submarine aircraft are mostly turboprop aircraft.

In terms of application, turboprop engines are suitable for long-flying drones at medium and high altitudes. Turboprop engine is a gas turbine engine commonly used in airplanes.

Turboprop engines are mainly used for aircraft with a speed of less than 800 kilometers per hour; turboshaft engines are mainly used as power for helicopters; turbine fan engines are mainly used for faster aircraft; turbojet engines are mainly used for supersonic aircraft.

The turbofan engine is mainly used in: civil aircraft. For example: Boeing 74737 and Airbus A380 and other civil aircraft.

Used for old-fashioned or light helicopters, old-fashioned or light propeller fixed-wing aircraft, power parachutes, rotorcraft, hovercraft, armored vehicles, etc.) It is characterized by simple manufacturing and maintenance technology, cheap, economical, and widely used in civil use.Two. Jet: Gas turbine engines are divided into five categories.