GROUP DYNAMICS OF REACTING JETS IN CROSSFLOW
Abstract
The purpose of this action is to add FY24 funds, in the amount of $125K, for a new start Grant. GRANT#14052046.--This program will focus on the group dynamics of multiple jets in cross flow, targeting multiple benefits for the navy warfighter: (1) shorter/lighter combustors, (2) improved turbine durability/life, and (3) reduced particulate/soot emissions. Multiple Jets in Crossflow (MJICF) are a common flow configuration where an array of jets is issued perpendicular to a cross stream. They are a critical flow configuration for navy warfighter applications, finding themselves in main combustion fuel injectors, augmentor fuel injectors, main combustor quench jets and film cooling jets. They play a key role in (1) rapid mixing of the fuel and oxidizer in the main combustor/augmentor, influencing thrust control and contrails, (2) rapid dilution in the quenching zone of RQL combustors, which directly controls the combustor length, emissions profile, and pattern factor and (3) protection of combustor surface from hot vitiated products by forming a film cooling layer, directly influencing durability and life. Hence, understanding the MJICF behavior is critical to make (1) shorter/lighter combustors/engines, (2) improve combustor and turbine durability/life, while (3) reducing particulate/soot emissions. Reacting jets in crossflow (JICF) are an important fundamental problem at the intersection of combustion and fluid mechanics. The reacting JICF problem can consist of either fuel injection into an air stream, such as in the main combustor and augmentor fuel injectors, or air injection into a fuel-containing stream, such as in the quench section of an RQL (rich, quick-quench, lean) combustor. The latter application is the focus of this proposed effort, as RQL combustors are the standard design used in Navy engines like the F135, and the performance cycle is sensitive to pattern factor. Studies that have characterized the jet trajectory and mixing of non-reacting Single JICF (SJICF) are routinely used to design the quenching/film cooling sections of MJICF. However, the behavior of the MJICF can differ from that of its SJICF counterpart due to competing pressure gradient effects and multiple interacting concentrated vortex regions. Currently, only a handful of papers exist that describe the MJICF flow field in a uniform density non-reacting environment, and there is little to no literature describing their behavior as the spacing or the number of jets varies, or in the presence of combustion. Preliminary work done on the uniform density MJICF configuration in non-reacting environment shows that the steady and unsteady features of the MJICF configuration are very different than the SJICF configuration. The focus of this proposed work is to further study the effects of operating conditions and the geometric layout of the MJICF on overall dynamics. This proposed program is for 3 years, leveraging our existing experimental facilities. We envision a TRL6.1-6.3 program with strong input from engine OEM s (Pratt & Whitney) that is flexible and in an appropriate parameter regime (quench jet momentum flux ratios, density ratios, etc.). The 6.1 component will consist of fundamental understanding of the MJICF followed by 6.2 and 6.3 components that will utilize this knowledge to suggest design changes to quench sections to optimize mixing. This work will be executed through a combination of experiments with state-of-the-art optical diagnostics and high-fidelity simulations. Approved for Public Release.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 08, 2024
- Source ID
- N000142412357
Entities
People
- Tim Lieuwen
Organizations
- Georgia Tech Research Corporation
- Office of Naval Research
- United States Navy