When the engine is running, the temperature inside the turbine is incredibly high; the fiery jet shooting out of the jet nozzle is a clear proof of that. It is even hotter at the turbine inlet, and the hotter the gas in front of it, the more powerful and economical the engine runs.

One of the most important parameters of the thermodynamic cycle of aviation GTEs is the gas temperature before the turbine. Its increase is the main tendency in improvement of aircraft GTE working process. The rate of its growth is connected with development of material science and technology, researches in the field of gas dynamics and theory of heat exchange with development of blades air cooling system.

It is the blades that have to withstand high centrifugal loads, without deforming or “sliding” over time. Creep is unacceptable because the clearance between the blade tips and the channel within which they rotate must be minimal for efficiency reasons, and any outward movement of the tip will result in catastrophic contact. Blade blades also encounter rain, hail, ice, repetitive thermal cycling in the high temperature range, icing, foreign objects and exposure to airborne chemicals.

The possibility of increasing the cycle operation by increasing the gas temperature upstream of the turbine allows increasing the second most important parameter of the thermodynamic cycle of aircraft GTEs – the degree of increase in the total pressure in the compressor.

The expediency of increasing the degree of pressure increase is determined not only by the possibility of increasing the cycle operation, providing the highest specific thrust and low specific fuel consumption, but also, first of all, by the increase in the efficiency of blade machines. Simply increasing cycle parameters, without a corresponding increase in compressor and turbine efficiency, does not allow to get an improvement in the quality of aviation GTEs corresponding to the next generation.

We live in the period of “change of generations of engines”. Complicated design of the inner cavity of the cooled blade in the engines of the last generation led to their thermo-fatigue failure with the operating time of only 30% of the resource.

In fact, the transition to the next generation is provided by a significant increase in the efficiency of vane machines at the same time as the gas temperature increases upstream of the turbine.