What model of turbofan jet engine with the largest thrust to weight ratio is there a parameter

The jet engine with the most thrust is the GE-90-115B equipped with the Boeing 777, with a maximum thrust of 569kn, or about 58,000 kg. The jet engine with the highest thrust-to-weight ratio is the ramjet engine, and the thrust-to-weight ratio can be as high as 30 or more for the compact ramjet engine.

The thrust-to-weight ratio of a turbojet engine is the land index ().

a.The ratio of the thrust of the engine to its structural weight at the maximum working condition on the ground.

b.The ratio of engine thrust to the weight of the flying limb at maximum operating conditions on the ground.

c.The ratio of the maximum thrust of the engine to the weight of its structure in flight.

d.The ratio of the maximum thrust of the engine to the weight of the aircraft in flight.

Correct Answer: a

Turbofan engine.

The thrust-to-weight ratio is high. Because of the turbofan.

The engine is more turbojet than the turbojet.

The working fluid flow rate is large, the injection speed is low, the propulsion efficiency is high, the fuel consumption rate is low, and the thrust is large.

A turbojet engine is a type of turbine engine. It is characterized by a complete dependence on gas flow to generate thrust. It is often used as a power source for high-speed aircraft.

Fuel consumption is higher than that of turbofan engines. The structure of a modern turbojet engine consists of an air intake, a compressor, a combustion chamber, a turbine and a tail nozzle, and an afterburner between the turbine and tail nozzle of a fighter jet.

A turbofan engine consists of a fan, a low-pressure compressor (unique to turbofans), a high-pressure compressor, a combustion chamber, a high-pressure turbine that drives the compressor, a low-pressure turbine that drives the fan, and an exhaust system. Among them, the high-pressure compressor, the combustion chamber and the high-pressure turbine are collectively referred to as the core engine, and the available energy in the gas discharged by the core engine is transferred to the low-pressure turbine to drive the fan, and the remaining part is used in the nozzle to accelerate the exhaust gas. When the core engine is the same, the working fluid (working medium) flow rate of a turbofan engine is between that of a turbojet engine and a turboprop engine.

Between. Turbofan engines have a larger working fluid flow, lower injection speed, high propulsion efficiency, lower fuel consumption and higher thrust than turbojet engines. The first generation of turbofan engines, developed in the 50s, had lower bypass ratios, compressor boost ratios and gas temperatures.

In the late 60s and early 70s, second-generation turbofan engines with high bypass ratios, high boost ratios and high gas temperatures were developed, with thrust up to 200 250 kN (20000 25000 kgf). The high bypass ratio turbofan engine has low noise and low exhaust pollution, and is mostly used as a large passenger aircraft.

The power plant, this airliner at an altitude of 11 km can reach a cruising speed of 950 km. However, this high bypass ratio turbofan engine has a low exhaust injection speed and a large frontal area, so it is not suitable for supersonic aircraft.

Above. Some fighters.

The turbofan engine with a small bypass ratio and afterburner is used, and the afterburner is not used when flying at subsonic speeds, and the fuel consumption rate and exhaust temperature are lower than that of the turbojet engine, so the infrared radiation intensity is weaker and it is not easy to be hit by infrared-guided missiles. When using afterburner to fly at more than twice the speed of sound, the thrust generated can exceed that of the afterburner turbojet engine, and the thrust-to-weight ratio under standard atmospheric conditions on the ground has reached about 8.

To correct a problem of the landlord, it is not possible to use the thrust-to-weight ratio to simply compare the engine. The thrust-to-weight ratio is the ratio of the total thrust of the vehicle to the total mass. The comparison of engines can only be done by looking at thrust and fuel consumption.

Turbojet fuel consumption is high, so modern large aircraft basically use turbofan engines, because of the same amount of fuel, the endurance of turbofans is definitely better than turbojet. Take the Tu-22 you mentioned as an example, the aircraft has an empty weight of about 34 tons, about 35-40 tons of fuel in the aircraft, a maximum take-off weight of 89 tons, and a maximum range of 5,500 kilometers, while the Tu-26, which was finalized a few years later, has an empty weight of 52 tons, an in-flight fuel of 48 tons, a maximum take-off weight of 130 tons, and a maximum range of 9,000 kilometers; The larger and heavier Tu-26 flew farther because of the use of two twin-rotor turbofans of the increased thrust type instead of the more fuel-intensive turbojets.

As for why the Tu-22 is in a turbojet? Probably due to the earlier design, there was no suitable turbofan engine, so in order to achieve sufficient thrust and supersonic flight, the only choice was to turbojet. The turbojet single afterburner thrust (12,250 kg) installed on the aircraft is about the same as the maximum thrust of the Tu-26 without afterburner (13,000 kg), and the single afterburner thrust of the Tu-26 HK-144 is 20,000 kg, which is nearly 3,000 kg higher than the total output of the two engines of the Tu-22 without afterburner.

The turbofan is high, the turbofan engine is actually a fan in front of the turbojet engine, this fan can improve the efficiency of the engine, so that the turbofan engine is more advanced than the turbojet engine in terms of thrust-to-weight ratio, fuel consumption, economy, life and other performance, as for Figure 22 does not use the turbofan engine I think is because there is no matching turbofan engine

This speed is also a little easier to use a rocket and then add a ramjet engine, but it is only for tactics with limited volume and mass**, and it can only ensure efficiency in the high-speed range.

Otherwise, it is a turbojet, and the outer duct of the turbofan at this speed does not produce thrust at all, and the weight and drag are cumbersome. It's better to push faster at higher speeds. The rattlrs actually requires a flight envelope that is basically a similar requirement, and if it is practicalized as a **, the acceleration to transonic speed should be by a rocket.

As for complexity and mass, a turbofan of the same class is certainly more complex than a turbojet. As for the lifespan, there is no comparison as a type, but for some parts, it is better to have a turbofan with a lower speed and a cooler.

1. Turbofan engine: It is a kind of jet engine, which is developed from turbojet engine, and is more fuel-efficient than turbojet engine. Now the vast majority of military and civilian aircraft are in service. It is the most common engine for civil airliners.

2. Turbojet engine: The earliest jet engine, which is more fuel-intensive, is basically not used now.

3. Turboprop engine: It is also developed from the turbojet engine, and the energy of the jet does not directly push the aircraft, but is used to drive the propeller and pull the aircraft forward. It is more fuel-efficient than the previous two engines, but it is slower and cannot reach supersonic speeds.

Some small and medium-sized military transport aircraft that do not pursue speed are often used.

All three engines use jet fuel as fuel.

4. Piston propeller engine: that is, the engine of the old aircraft before World War II, which relies on the piston to drive the propeller to rotate through the crankshaft, and cannot reach supersonic speed. It is now largely extinct.

Only a very small number of civilian small aircraft are used. This engine runs on aviation gasoline and has the lowest cost.

Let's list them according to the news.

1. Xiaolong, "Taishan" engine, imitating Russian RD33.

2. Flying Leopard, "Qinling" engine, imitating the British "Spey" engine. Qinling is a nationally produced + improved version of the "turbofan-9" engine.

3. J-10, AL-31 engine imported, it is also said to be WS10, imitating AL31 and the United States F100 Pratt & Whitney patchwork, the technology is not yet mature.

4. Yun 20, using D-30 engine, and then will use WS-18 engine or FWS-10 engine modified model.

That's basically it!!

WS18 is a copy of the D30 of Maozi by Chengfei Engine Company, according to the relevant data of the aircraft manual, the parameters of the D30 engine are take-off thrust (DAN): 10790 (maintained to 21 degrees), thrust-to-weight ratio: without thrust reverser).

Considering that WS18 is basically the same as the prototype, nothing has changed, so the thrust-to-weight ratio should also be in between.

Turbocharged engines are used in cars, while turbojet engines and turbofan engines are used in airplanes – and that's a difference.

Schematic diagram of the turbo increase engine:

The difference between turbojet engine and turbofan engine is: turbofan engine has more fans, internal and external ducts and other components than turbojet engine.

Turbojet engine: This type of engine is basically based on the same principle as the jet mentioned above, with the advantages of fast acceleration and simple design. However, if you want the turbojet engine to increase its thrust, it is necessary to increase the temperature and boost ratio of the gas before the turbine, which will increase the exhaust speed and lose more kinetic energy, so there is a contradiction between increasing thrust and reducing fuel consumption.

Therefore, the turbojet engine has high fuel consumption, which is an Achilles' heel for commercial civil aircraft.

Schematic diagram of turbojet engine:

Turbofan engine: Part of the air sucked in by the turbofan engine is blown from behind the external duct (outer duct), and part is sent to the core engine of the inner tunnel (equivalent to a pure turbojet engine). The front-end "fan" acts like a propeller and improves the propulsion efficiency of a jet engine by reducing the exhaust velocity.

At the same time, through precise design, more gas energy is transmitted to the outer duct through the fan, which also solves the problem of excessive exhaust speed, thereby reducing the fuel consumption of the engine. Because the fan design needs to take into account the needs of internal and external ducts, it is much more difficult than a turbojet engine.

Schematic diagram of turbofan engine:

I hope you will adopt it!

There is not much difference in appearance.

The common denominator of both is that the compressor compressed air is burned and expanded in the combustion chamber, and the work is done to push the turbine, and the turbo drives the compressor. This is also the basic working principle of a gas turbine engine.

The difference is that turbojet engines only have a single flow channel. Turbofan engines, on the other hand, are usually based on ordinary twin-rotor turbojet engines, with a turbine-driven fan and an outer cover (forming an outer duct). The difference in structure is this, you can see that the fan-like thing in front of the turbofan is the blades of the compressor, while in front of the turbofan engine is the fan.

The turbofan engine structure has an external duct and an inner channel, and the air sprayed out of the outer duct directly expels the engine to generate thrust, and the internal channel enters the combustion chamber.

The ratio of the air quality flow of the outer duct and the inner duct of the turbofan engine is called the duct ratio. A bypass ratio of less than 1 is defined as a small bypass ratio, a bypass ratio greater than 4 is defined as a large bypass ratio, and a bypass ratio greater than 1 and less than 4 is a medium bypass ratio. The bypass ratio is an important design parameter for turbofan engines, which has a great influence on the engine's fuel consumption rate and thrust-to-weight ratio.

The advantage of the turbofan engine is that under the same gas generator, the air flow of the turbofan engine is large and the exhaust speed is low, so the propulsion efficiency is high, the fuel consumption rate is low, and the noise is low. The unpowered turbofan engine is the ideal power for high-subsonic passenger and transport aircraft; Turbofan engines with afterburner are suitable for supersonic military aircraft.

Turbojet is the work done by mixing air with gas after compression, and the turbofan is part compressed combustion and part is used for cooling.

Turbo injection: The combustion gas pushes the turbine to drive the compressor and then sprays it directly, the temperature is high and the speed is fast, so it is inefficient and suitable for supersonic work.

Turbofan: After the combustion gas pushes the turbine to drive the compressor, it is also mixed with part of the cold air separated from the front-end low-pressure compressor (the proportion is the channel ratio), and then the gas with increased flow, speed and temperature is sprayed, so that the thrust increases in the case of subsonic flight, the efficiency is also improved, and it is more fuel-efficient, although the structure is more complex, but the most occasions are used (in most cases, including the fighter jet is flying at subsonic speed, the supersonic drag increases dramatically, and it costs a lot of fuel consumption). However, when flying at supersonic speeds, the efficiency decreases due to the low jet speed.

The ramjet engine is to replace the low-pressure compressor or high-pressure compressor by the dynamic pressure head during hypersonic flight, which is directly like fuel mixed combustion. The structure is simple, but it is necessary to reach hypersonic speed in order to start work. In addition to the increased drag, the aircraft will also be aerodynamically heated, and the structural and economic costs of heat insulation and heat dissipation will also be paid for supersonic flight in the atmosphere.

In addition, there is a type called slurry fan engine (not turboprop), which is directly pushed by the high-speed blades of a large-size low-pressure compressor without passing through the reducer (called a turboprop through the reducer), which is more fuel-efficient, simple in structure, and has a very special blade shape.

The two engines mentioned above are used in airplanes, so check the aircraft engines yourself, because they can't be said clearly in one or two sentences.

There are two turbofan airflow channels: connotation and connotation. The connotation should pass through the fan, compressor, combustion chamber, turbine and nozzle port; The outer connotation is discharged directly through the rear capacity of the fan.

If it is an afterburner engine (such as the engine of a military aircraft such as the F-22: F-119, etc.), the outer airflow will also pass through the Gary combustion chamber. Now civil aviation almost does not use turbojet (subsonic speed is not economical), CFM56, GE90, PW4000, RB211, TRENT, etc., are typical turbofan engines without afterburner.

There is only one turbojet airflow channel. The efficiency is higher at high speeds. However, it is very waste oil. Now even fighter jets rarely use pure turbojets. Early jet engine turbojets were the majority. For example, the JT3D used in the 707 is a turbojet engine.

Compared to turbojet engines, turbofan engines have high thermal efficiency and low fuel consumption, resulting in a large thrust-to-weight ratio. These are things that turbojet engines are difficult to reach anyway. In fact, the core engine of turbojet engine and turbofan engine is basically the same, the difference is that the turbofan engine is based on the turbojet engine with several stages of turbines, these turbines drive a row or several rows of fans, part of the air flow after the fan enters the compressor (connotation channel), and is sprayed out from the nozzle after combustion, and the other part is directly discharged into the air through the outer duct without combustion.

So, the thrust of the turbofan engine is the sum of the fan resistance and the nozzle thrust.