Numerical approach to the modelling of transient interaction of prospective combustor concepts and conventional high pressure turbines

F. Bakhtiari ^*, H.-P. Schiffer

Technische Universität Darmstadt, Institute of Gas Turbines and Aerospace Propulsion, Darmstadt 64287, Hessen, Germany

Abstract: The Institute of Gas Turbines and Aerospace Propulsion at Technische Universität Darmstadt conducts research projects in the field of “combustor turbine interaction” (CTI). This paper presents numerical studies on the interaction between novel combustion concepts and conventional “high pressure turbine” (HPT) stages.
         In order to obtain higher efficiency and reduce emissions of jet engines, it is necessary to apply innovative and revolutionary technologies. The most promising technical solutions are based on the cycle processes, employing “pressure gain combustion” (PGC) methods. PGC methods provide a significant thermal efficiency enhancement and low NOx-emission rates at the same time.
         The investigations presented in this paper give information on the integrability of revolutionary combustion concepts into conventional engine architecture. This paper aims at providing insight into the numerical modelling of the transient behaviour of prospective combustion outflow and its influence on the operation of HPTs, especially on the first stage. The focus is on the aerodynamic effects and loss mechanisms within the blade passage. The interaction between the two components plays an important role. To study the performance under new conditions, an engine-like HPT geometry is used.
         This study reveals a decrease in turbine efficiency with transient inflow conditions compared to a steady-state inflow case. The decrease is primarily due to the interaction between transient inflow and the loss mechanisms in the turbine.
The presented research was done as part of the project “Technologien für REVolutionäre Arbeits Prozesse” (TREVAP).

Keywords: Combustor turbine interaction (CTI); Prospective combustor concepts; Pressure gain combustion (PGC); High pressure turbine (HPT); Transient computational fluid dynamics (CFD)