The propeller engine is more fuel -efficient. Why do the passenger aircraft choose a turbo fan engine?Results of internal volumes

The aircraft can soar in the blue sky, and the engine is definitely indispensable, and the engines equipped by modern aircraft are nothing more than two types, namely the propeller engine and jet engine.

Needless to say, the aircraft equipped with a propeller engine, the high -speed rotating propeller has a high degree of recognition. So what are the planes equipped with jet engines? Maybe you first think of various civil aviation passenger planes represented by "Boeing" and "Airbus". Indeed, there are no high -speed propellers outside these civil airliners, but they say that they are equipped with jet engines, and they seem a little rigorous. Why do you say that?

Strictly speaking, the engines on these civil airliners should be called "turbine fan engines". It is very different from the turbine propeller engine in appearance, but it is quite similar in terms of working principles.

When the turboprop engine starts working, the air will enter from the compressed blades in front of the engine. After becoming a compressed air, it will enter the combustion room and the fuel to be fully mixed with the fuel. At this time The sprayed gas will promote the turbine blades behind the engine. The turbine blades then transmit the kinetic energy to the gearbox in front of the engine through the transmission shaft, so the propeller in front of it rotates.

With the working principle of the turbine propeller engine, can you see what force does the aircraft equipped with this engine fly forward?

It is not the high -temperature gas sprayed back in the rear, but the air that is accelerated by the propeller in front and quickly launched. This part of the gas is also called "bypass air". Let's take a look at the turbine fan engine. Its working principle is actually similar to the propeller engine. The difference is just to replace the exposed propeller into a fan installed inside.

When the turbine starts to work, the fan in front begins to rotate, and a large amount of air influx from the front, but these influx of air will be divided into two parts.

Part of the compressed air enters the burning room, and eventually it becomes high -temperature gases from the rear, while the other part is directly pushed to the rear by the fan. "Winger air". Obviously, whether it is a turboprop engine or a turbo fan engine, the forward force comes from the bypass air driven by the blades, rather than the high -temperature gas sprayed directly backwards. Jet engine.

The real jet engine is fully relying on the high -temperature gas sprayed backwards. This engine is usually only installed on a fighter.

Although the turboprop engine is similar to the principle of the turbine fan engine, the efficiency is different. Under the same fuel consumption, the propeller aircraft is obviously more efficient, because all the air promoted by the propeller is the bypass air that drives the aircraft, and the turbine fan Part of the air promoted in the air will become compressed air entering the combustion room. In this case, why do civil aviation passenger aircraft use the turbo fan engine? Because the propeller engine has a disadvantage, it can't fly too fast.

What should I do if the propeller plane wants to increase the speed?

You have to make the propeller rotate faster, but the speed of the propeller rotation is limited, because once the propeller rotates the speed of the sound, it will generate a wave of waves, that is, a wedge or cone will appear at the tip of the propeller. The air wave, which will cause the efficiency of the propeller to decline directly. However, the turbine fan engine has no such problem at all, because the airway of the turbine fan engine is specially processed. After the airflow enters, the speed will be reduced rapidly, and naturally it will not generate a ride in front of the fan. It can be seen that the two engines have their own advantages and disadvantages. The propeller engine is efficient, but the speed is slow. Although the turbine fan engine is relatively fuel -consuming, the speed is fast. For civil aviation companies, of course, it is more cost -effective to choose a fuel -saving propeller engine, but you choose a propeller. Other companies use turbine fan engines. Who will come to sit on your slow aircraft? This is also a kind of inside.

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