Numerical Simulation of the Multistage Ultra-High Efficiency Gas Turbine Engine, UHEGT Conference Paper uri icon

abstract

  • Copyright © 2017 ASME. The Ultra-High Efficiency Gas Turbine Engine (UHEGT) was introduced in our previous studies [1]-[3]. In UHEGT, the combustion process is no longer contained in isolation between the compressor and turbine, rather distributed in multiple stages and integrated within the high-pressure turbine stator rows. Compared to the current most advanced conventional gas turbines, UHEGT considerably improves the efficiency and output power of the engine while reducing its emissions and size. In the present study, a complete six-stage turbine with three stator internal combustors is designed for UHEGT. The turbine is designed for a single spool turboshaft system used for power generation. A thermodynamic cycle that has a base thermal efficiency of above 45% is designed based on an ideal mixture of methane and air. Preliminary flow path for each turbine stage is designed by 1D/2D approach (meanline calculation). The combustors, designed based on our previous [1] and parallel studies, consist of cylindrical tubes extended from hub to shroud with thin slots on top and bottom for gaseous fuel injection. CFD calculation (via ANSYS CFX) is used to simulate the high pressure turbine stages (stage 1 to 3). The simulations are unsteady, they are performed for ten total components and include a multi-species combustion process along with the rotor motion. The flow path is modified based on the CFD results in order to reduce separation and losses while enabling maximum mixing of fuel and air and reducing temperature nonuniformities. Flow patterns, secondary flow losses, temperature distribution, and pollutant emissions are presented and analyzed in the results. The results show that a relatively uniform temperature distribution is achieved at the inlet of each rotor and the system performs very well regarding the output power and flow patterns.

author list (cited authors)

  • Ghoreyshi, S. M., & Schobeiri, M. T.

citation count

  • 9

publication date

  • June 2017