A helmholtz-type numerical simulation of thermo-acoustic instabilities in a 3-d rijke tube


Cengiz K., ÖZYÖRÜK Y.

49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, JPC 2013, California, Amerika Birleşik Devletleri, 14 - 17 Temmuz 2013 identifier

  • Cilt numarası:
  • Doi Numarası: 10.2514/6.2013-4060
  • Basıldığı Şehir: California
  • Basıldığı Ülke: Amerika Birleşik Devletleri

Özet

© 2013, American Institute of Aeronautics and Astronautics Inc. All rights reserved.A thermo-acoustic instability prediction tool has been developed both for 2-D and 3-D ducts. The tool works in frequency domain, making use of linearized Euler equations with quiescent flow. In this work, a 3-D horizontal Rijke tube simulation is performed. Nonetheless, implementation of open boundary condition at the duct ends somewhat requires close attention. A reverse idea has been developed to determine the open-air boundary condition. Numerical tests showed that the method works well in 2-D cases, involving solution of a linear system with dense matrices. However, the pertinent complex-valued matrix turns out to be highly ill-conditioned in the 3-D case. This work proposes use of Singular Value Decomposition(SVD) to remedy this problem. QR decomposition is to be examined as well, as a performance and accuracy comparison. Results obtained for the Rijke tube problem validates the tool, at least, for linear stability requirements.