Surge - what is it? This definition means disruption of the stable operation of an aircraft engine, a violation of its gas-dynamic performance. The surge of the engine is accompanied by a sharp loss of thrust, pops with the emission of 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 occurs as a result of the loss of stable rotation of the turbine blades. The process tends to self-increase. The resulting air turbulence disrupts the rhythm of the engine. Repeated rotation of the same heated portion of air in the turbine causes a significant increase in the temperature of the aircraft engine compressor.
Surge - what is it? The operation of the engine in surge mode eventually leads to its damage with subsequent destruction. This is facilitated by the loss of strength of the blades and the explosions of portions of exhaust gases as a result of an excessive increase in temperature.
How to eliminate the surge during the flight?
What do pilots do to eliminate turbocharger surge while an aircraft is moving? When a problem is identified, to begin with, the aircraft engine is transferred to the “low gas” mode or is completely turned off. In the latter case, the surge effect disappears on its own. It is worth noting that when a problem occurs, the temperature of the gases in the turbine rises to catastrophic levels in seconds. Therefore, the timely shutdown of a damaged engine is extremely important in terms of preventing disaster.
Modern aircraft engines are equipped with fire-fighting automation. Its operation contributes to the elimination of factors that cause engine surge, without the need for targeted actions on the part of the aircraft crew. Thanks to the automation, the pressure in the turbine area is reduced for a fraction of a second, and the fuel supply is also interrupted. All this makes it possible to avoid further ignition of the engine in flight.
Engineering solutions to eliminate engine surge
The main way to deal with the occurrence of surge in aviation is to install engines 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 part of the turbine and compressor.
Among other things, engineers provide for the following:
- Install adjustable rotary blades on the engine turbines. This helps to improve the blowing of the blades, on whichin fact, breakdowns are formed during surge.
- Use air bypass valves to relieve excess pressure in the engine compressor. This makes it easier for the air to circulate through the compressor.
Reasons
So we found out what surge is in aviation. Now let's look at the reasons that can lead to such an accident. Surge can be triggered by:
- lifting the aircraft to its extreme angles of attack;
- tearing off or partial destruction of turbine blades, for example, due to their obsolescence, expiration date;
- getting into the engine turbine of a foreign object (garbage, fragments of the runway cover, a flying bird);
- engineering errors in the design of the engine or its control systems;
- strong crosswind gusts;
- critical decrease in atmospheric pressure (may occur when the aircraft is moving in mountainous areas in hot weather).
In closing
In the presented material, we figured out what surge is. As you can see, there are a whole host of solutions to deal with such emergency situations. First of all, this is the manual shutdown of the damaged turbine by the aircraft crew, the automatic restart of the aircraft engine by special systems, the preliminary operation of all kinds of signaling devices that inform the pilots about the danger of engine fire. Given the above, you should not be afraid of flying on air transport, because suchaccidents are now extremely rare.
