Surge - what is it? Reasons and solutions

Surge - what is it? By this definition we mean the failure of the stable functioning of the aircraft engine, the violation of its gas dynamic parameters. The surging of the engine is accompanied by a sharp loss of traction, slamming the smoke and flame from the turbines, the occurrence of significant vibrations on board the aircraft. Often, all this leads to the destruction of the engine.

What happens when an aircraft engine surges?

Surge - what is it? This phenomenon arises as a result of the loss of stable rotation of the turbine blades. The process tends to self-increase. The resulting air vortices knock down the rhythm of the engine. Multiple rotation of the same heated portion of air in the turbine causes a significant increase in the temperature of the compressor of the aircraft engine.

Surge - what is it? The functioning of the engine in surge mode ultimately leads to its damage, followed by destruction. This contributes to the loss of strength of the blades and explosions of portions of the exhaust gases as a result of excessive temperature rise.

How to eliminate surging during the flight?

What do the pilots do to eliminate the surging turbocharger during the movement of the aircraft? If the problem is identified, the aircraft engine is switched to "small gas" mode or disconnected altogether. In the latter case, the surging effect disappears by itself. It should be noted that if a problem arises, the temperature of the gases in the turbine increases to catastrophic values in seconds. Therefore, timely shutdown of a damaged engine is extremely important in terms of preventing a catastrophe.

On modern aircraft engines install fire-fighting automatics. Its functioning helps to eliminate the factors that cause engine surges, without the need for targeted actions from the crew of the aircraft. Thanks to automation, the pressure in the turbine area drops for a fraction of a second, and the fuel supply is interrupted. All this makes it possible to avoid further ignition of the motor in flight.

Engineered solutions for removing engine surges

The main way to combat the emergence of surging in aviation is the installation of aircraft with coaxial shafts on aircraft. The latter are able to rotate independently with respect to each other at different speeds. Each coaxial shaft is responsible for a part of the turbine and compressor.

Among other things, engineers provide the following:

1. Install adjustable rotary vanes on the turbines of the engine. This contributes to the improvement of bladder blasting, in which, in fact, failures are formed during surging.
2. Use the air bypass valves, which relieve the excess pressure in the engine's compressor. Thus, air circulation through the compressor is facilitated.

Causes

So we found out what a surge in aviation was. Now let's look at the reasons that can lead to such an accident. The surge can be caused by:

• The withdrawal of the aircraft to the angles of attack that are beyond its limits;
• Tearing or partial destruction of turbine blades, for example due to their obsolescence, expiration of the expiry date;
• Hit the turbine engine of an alien object (debris, fragments of the runway, flying bird);
• Engineering errors in the design of the engine or its control systems;
• Strong gusts of the side wind;
• A critical drop in atmospheric pressure (it can occur when the aircraft is traveling in mountainous terrain in hot weather).

Finally

In the presented material, we figured out the surging - what is it. Apparently, there is a whole mass of solutions for dealing with such accident-prone phenomena. This is primarily the manual shutdown of the damaged turbine by the crew of the aircraft, the automatic restart of the aircraft engine by special systems, the pre-operation of various alarms, which inform pilots of the danger of engine ignition. Given the above, do not be afraid of flights on air transport, because such accidents now occur extremely rarely.