Detached-eddy Simulation with Turbulent Combustion in the Turbine Stage for Enhanced Performance
Abstract
The turbine burner for turbo-fan and turbojet engines offers an exciting opportunity for improved efficiency and greater power for either thrust or auxiliary purposes. Our well cited papers [1, 2] show the thermodynamic foundations for obtaining significantly improved performance by burning additional fuel with the products of fuel-lean primary combustor. Heat release in the expanding flow through the turbine adds to the power and efficiency level while still maintaining the limitations on material temperature. It can be more efficient than traditional afterburners because the combustion occurred at higher pressure. Secondly, by burning in the turbine, the power is available for either augmented thrust or auxiliary functions. For turbojets that might be used for some unmanned aircraft, a single auxiliary turbine-burner may achieve 10-30% specific thrust (ST) increase for flight Mach number range of 0 to 2 while keeping specific fuel consumption (SFC) almost identical for subsonic flight and a slight increase for supersonic flight all without the added weight and hefty SFC of an afterburner. Even greater percentage gains in ST and SFC are achievable by the turbine-burner configurations when used in the turbofan engine for manned or unmanned aircraft. We are ready to make a large leap forward in our analysis and understanding of the potential for turbine burners. Computational capabilities now allow us to consider burning through both the stator and rotor. Better computational analysis of the turbulent combustion and accelerating transonic flow is now possible through large-eddy simulation (LES). [6-10] Improved sub-grid flamelet modelling is now available. [7-10] The capability for considering both liquid-phase and gas-phase behaviors in coupled fashion exists. The research will focus on computational analysis of the flow through a turbine stage, both stator and rotor, with the special feature of fuel injection into the accelerating hot mixture of air and combustion products from the primary upstream burner. The goals are to provide relevant details and patterns concerning the turbulent mixing and combustion of the reactants, how it affects turbine power output, how it affects heat transfer to the turbine blades, and how it affects the mixture that flows to the next stage or to a nozzle. Thus, collectively from the information produced, an understanding of performance with the new concept will be determined. In parallel to the above investigation into the fundamental flow and combustion physics for the advancement of the turbine-burner concept, we will also perform system analysis of the basic thermodynamics and fluid dynamic cycle of the turbine-burner engine. Both on-design and offdesign analysis tools for engine performance simulation using different turbine-burner configurations will be developed. Parametric studies will be performed to determine the optimal engine configurations and appropriate flight applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 08, 2022
- Source ID
- N000142212467
Entities
People
- William A. Sirignano
Organizations
- Office of Naval Research
- United States Navy
- University of California, Irvine