Flame Characteristics and Fuel Entrainment Inside a Cavity Flame Holder in a Scramjet Combustor (Postprint)

Abstract

Flame structures and operating limits of an ethylene-fueled recessed cavity flameholder were investigated both experimentally and numerically, using a newly developed AFRL research scram jet flowpath at Wright-Patterson Air Force Base. Flush-wall low-angled injectors were used as main fuel injectors. The recessed cavity features an array of fueling ports on the aft ramp for direct cavity fueling. The cavity operating conditions include 1) direct cavity fueling, 2) direct cavity fueling with back pressurization, and 3) fueling from main injectors with and without direct cavity fueling. With direct cavity fueling, significant variation in the shape and spatial distribution of the cavity flame was observed at various fuel flow rates with and without back pressurization. It was found that both lean ignition and blowout limits increase with the characteristic air flow rate. The lean blowout limit is decreased toward a lower value as the shock train is pushed toward upstream. With fueling from main injectors, the flame is mainly distributed within the body wall comers for the present flowpath.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 2007
Accession Number
ADA479694

Entities

People

  • Campbell Carter
  • Chung-jen Tam
  • Isaac Boxx
  • Kevin M. Jackson
  • Kuo-chen Lin
  • Martin Lindsey

Tags

Communities of Interest

  • Air Platforms
  • Biomedical
  • Materials and Manufacturing Processes
  • Space

DTIC Thesaurus Topics

  • Air Flow
  • Air Force
  • Air Force Facilities
  • Boundary Layer
  • Cameras
  • Combustion
  • Combustion Products
  • Combustors
  • Computational Fluid Dynamics
  • Fuel Injectors
  • Ignition
  • Ignition Lag
  • Laser Induced Fluorescence
  • Photographs
  • Pressurization
  • Spatial Distribution
  • Turbulent Mixing

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Fluid Mechanics and Fluid Dynamics.