Variably Premixed Rotating Detonation Engine for Evaluation of Detonation Cycle Dynamics

Abstract

A variably premixed rotating detonation engine using gaseous hydrogen and air reactants is introduced to enable investigation of key cycle processes while varying the homogeneity of the reactant inlet conditions. Two chamber configurations are investigated, the first with reactants filling the entire span of a straight annular channel and the second with a slightly larger channel and a backward-facing step. The first configuration permits both premixed and non-premixed fuel injection, enabling mixing quality modulation. The second configuration is operated only at fully premixed conditions. Operating modes and detonation wave speeds are characterized using exhaust-plume imaging, while the chamber heat release field is captured by transverse imaging through a transparent outer body. Tests using the first configuration were characterized by unstable counterpropagating modes with low detonation wave speeds regardless of the state of premixing, while the second configuration rendered single-wave behavior with wave speeds up to 86% of the Chapman–Jouguet velocity. Comparisons with a simple computational fluid dynamics model of the second configuration indicate that reactant preheating significantly influences the detonation wave topology, highlighting the potential utility of the test platform for isolating key physics associated with the effects of reactant premixing, preheating, and chamber geometry on rotating detonation engine operation.

Document Details

Document Type
Pub Defense Publication
Publication Date
May 01, 2023
Source ID
10.2514/1.b38868

Entities

People

  • Daniel E. Paxson
  • Terrence R Meyer
  • Venkat Athmanathan
  • Zachary M. Ayers

Organizations

  • Air Force Research Laboratory
  • Defense Threat Reduction Agency
  • National Aeronautics and Space Administration
  • Purdue University

Tags

Fields of Study

  • Physics

Readers

  • Combustion Dynamics and Shock Wave Physics.
  • Combustion and Flow Dynamics.
  • Combustion science or combustion engineering.