Авіаційно-космічна техніка та технологія (Aug 2023)
Analysis of the influence of the place of water injection on the performance of turbofan engine with afterburner
Abstract
An important direction for the development of high-speed aircraft is the expansion of the range of operation of aircraft engines as part of their power plants. Currently, the range of operation of aircraft engines in terms of altitude and flight speed is limited by the ability of construction materials to withstand the temperature of the working body. Therefore, to expand the range of operation, it is necessary to either change the construction materials or use technologies that involve cooling the working body. The water injection system in a turbofan engine with an afterburner allows cooling of the working body without significant interference with the structural profile of the engine, which significantly saves design time and development cost. In addition, water injection has long been used for a short-term increase in engine thrust, which is an additional advantage of using this system. The choice of the place of water injection into the engine tract has a great influence on its characteristics and on the ability of the high-speed aircraft to perform the assigned tasks. Therefore, the design of the engine must take place with an understanding of the intended purpose of the high-speed aircraft. This article analyzes the influence of the place of water injection on the characteristics of a turbofan engine with an afterburner. I will consider water injection at the inlet to the fan and at the inlet to the high-pressure compressor. The influence of injection site and flight conditions on water consumption is shown. Operating conditions were found in which it is impossible to use a turbofan engine with an afterburner due to restrictions not related to the temperature of the working fluid. The results of calculations regarding the influence of the water injection site on the main thermodynamic parameters and traction characteristics of the engine are given. The application of the obtained results will increase the thermodynamic efficiency and extend the operating range of two-circuit turbofan engines with afterburners using modern materials. The results of this work will also make it possible to shorten the period of development of competitive engines for high-speed aircraft through a targeted search for their rational thermodynamic and structural-geometric outline.
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