Pockets in highly turbulent premixed flames: physics and implications on modeling
Abstract
Efficiency and stability are two major design criteria for modern aeronautical engines, and bothare strongly affected by the physical processes inside the combustors. The primary objective ofthe proposed research is to understand the underlying physical processes of the highly turbulentpremixed flames. Specifically, two kinds of “pockets” that are present within the broken reactionregimes will be targeted as the central quantity of interest: the fresh-mixture pockets on theproduct side of the flame (“FiP”) and the product pockets on the fresh mixture side of the flame(“PiF”). The existence of these pockets is a distinctive feature of flames within the brokenreaction zones, and is hypothesized to be the possible causes for the deviation of the flamestatistics from flames that are within the flamelet regimes. A priori analysis of the directnumerical simulations (DNS) of several highly turbulent premixed flames is employed to probethe local physiochemical states that create these pockets. The collected information will then beused as initial and boundary conditions to conduct a systematic DNS investigation of a series ofparametric unit problems that contain isolated “PiF” and “FiP” pockets. Based on the results, anextinction-reignition map and a modified regime diagram will be constructed. Computationaldiagnostics will be applied to the DNS results to provide a dynamic description of key modelingquantities. If successful, this project will provide a transformative way to understand the highlyturbulent flames, which can facilitate the improvement of efficiency and stability of modernengines.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 09, 2018
- Source ID
- FA95501810173
Entities
People
- Xinyu Zhao
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Connecticut