Numerical Simulation of a Gas Turbine Engine with Constant Volume Combustion

There is a growing interest in alternative gas turbine thermodynamic cycles that could provide improvements in thermal efficiency and consequently in fuel saving. One of these engines is represented by the constant volume combustion gas turbine, in which the combustion process does not take place at constant pressure, like in conventional gas turbine, but at constant volume. The main characteristic of this thermal cycle is that the pressure increase is not provided entirely by the compressor, but partly by the compressor and mainly by the combustion process, that taking place in a closed volume makes the pressure rise. In this way, since the power absorbed by compressor is less respect to the conventional gas turbine, the power available and the thermal efficiency could have benefits. By means of a thermodynamic numeric program that simulates the constant volume combustion turbine behavior, a parametric study is performed, computing the main system performances, as specific power and thermal efficiency. The program, together with the ideal cycle, simulates the non steady working conditions of the system, putting in evidence the importance of the turbine efficiency on the achieved performance levels. © 2012 by Roberto Andriani.