Multi-Fidelity Framework for Modeling Combustion Instability

Abstract

A multi-fidelity framework for combustion instability modeling is established by integrating a reduced order model (ROM) for combustion response into the linearized Euler equations. The ROM is developed from CFD simulations of periodic forcing on a reduced domain using Galerkins method to reduce the high-order PDEs to a lower-order ODE system via POD eigen-bases generated from the reduced-domain dataset. Evaluations of the framework are performed based on simplified test problems for a model rocket combustor showing distinguishable instability behaviors. The coupling between the ROM and the Euler equations requires two-way information transfer between the two systems. Results show that the fraction of the complete domain represented by the ROM can be chosen to simplify the interaction between the two levels of solution. The multi-fidelity model is capable of capturing the overall instability trends although some discrepancies due to unstable generic responses arising from the reduced-domain simulations.

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Document Details

Document Type
Technical Report
Publication Date
Jul 27, 2016
Accession Number
AD1014963

Entities

People

  • Charles L. Merkle
  • Cheng Huang
  • Venkateswaran Sankaran
  • William E Anderson

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force Research Laboratories
  • Back Pressure
  • Chambers
  • Chemical Reactions
  • Combustion
  • Combustion Chambers
  • Combustors
  • Computational Fluid Dynamics
  • Computational Science
  • Differential Equations
  • Equations
  • Euler Equations
  • Flow Rate
  • Frequency
  • Reliability
  • Test And Evaluation
  • Turbines

Fields of Study

  • Physics

Readers

  • Computational Fluid Dynamics (CFD)
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)