Improvement of gas turbine engines due to isothermal expansion in the turbine

The article presents the results of the study of application of isothermal expansion in the turbine of gas turbine engines as a way of improving the thermodynamic cycle. We present equations of work and ideal cycle efficiency of a gas turbine engine with isothermal expansion in the turbine. We performed a comparative analysis of the cycle under consideration and the traditional cycle of a gas turbine engine with adiabatic expansion on the basis of the equations mentioned above. In order to carry out a thermodynamic study of real isothermal expansion in the turbine of a gas turbine engine on the basis of 3D numerical simulation we examined the turbine characteristics and determined corrections of an adiabatic- expansion turbine characteristics for isothermal expansion. By using the obtained correction data and characteristics, on the basis of the method formed, we investigated the use of isothermal expansion in gas turbine engines of various schemes based on thermodynamic calculation at a set point and calculation of altitude-speed performance. The studies prove the efficiency of using isothermal expansion as a way of improving the thermodynamic cycle of turbojet engines and turbofan engines with a low-bypass ratio, in particular with reference to supersonic military and civil aircraft.