Combustion Dynamic Analysis of Gas Turbine Engine
|International Journal of Engineering Trends and Technology (IJETT)||
|© 2017 by IJETT Journal|
|Year of Publication : 2017|
|Authors : M.V.H.Satish Kumar
|DOI : 10.14445/22315381/IJETT-V50P254|
M.V.H.Satish Kumar "Combustion Dynamic Analysis of Gas Turbine Engine", International Journal of Engineering Trends and Technology (IJETT), V50(6),321-328 August 2017. ISSN:2231-5381. www.ijettjournal.org. published by seventh sense research group
The need for better fuel efficiency and less exhaust emissions has prompted rapid advancement in today’s gas turbine engines. These innovations require more accurate condition monitoring systems to achieve optimal gas turbine performance. Burning a leaner flame reduces NOx emissions but may increase instability (combustion dynamics) at the same time. Combustion Instability can damage components in the combustion chamber such as nozzles, baskets, transition pieces and downstream components such as blades, resulting in downtime and loss of revenue. The aim of this Project is to analyse the behaviour of a backward-facing step non-premixed combustor using Computational tools & compare the results with experimental data already available. Different parameters affecting the various stages & aspects of combustion process such as unsteady heat release, incomplete combustion, noise generation, interaction between flame, flow field & acoustics are intensively studied. In this Project, combustion process of methane & air in a Backward Facing Step Combustor was examined using ANSYS Fluent Package for the acoustic excitation. 3-component velocity measured downstream of the inlet was used to determine the spatial average of turbulent intensity. The instantaneous and average velocity fields for both cold and combusting flows have been obtained using CFD package FLUENT.
1) Chakravarthy S. R, O. J. Shreenivasan, Benjamin Boehm, Andreas Dreizler and Johannes Janicka (2007) Experimental characterization of onset of acoustic instability in a non-premixed half-dump combustor. Journal of Acoustical Society of America, 122 (1), 120–127.
2) Chakravarthy S. R, R. Sivakumar and O. J. Shreenivasan (2007) Vortex acoustic lock-on in bluff-body and backward-facing step combustors. Sadhana, 32 (parts 1 & 2), 145–154.
3) Abu-Mulaweh, H.I., T.S. Chen, and Armaly B.F. (2002), Turbulent mixed convection flow over a backward-facing step the effect of the step heights, International Journal of Heat and Fluid Flow, 23, 758-765.
4) M.A.Z. Hasan (1991) The flow over a backward-facing step under controlled perturbation: laminar separation.
5) Chiang, T.P. and T.W.H. Sheu (1999), A numerical revisit of backward facing step flow problem, Physics of Fluids, 11, 862-874.
6) Cohen, J.M. and T.J. Anderson (2003), Experimental investigation of near blowout instabilities in a lean, premixed step combustor, AIAA-96-0819.
7) Davis, J.A., N.M. Komerath, R.E. Walterick, W.C. Strahle, and S.G. Lekoudis (1986), Acoustic behavior of an SFRJ simulator, AIAA-86-0003.
8) Fureby, C. (2000), A computational study of combustion instabilities due to vortex shedding, Proceedings of the Combustion Institute, 28, 783-791.
9) Ganji, A.J. and R.F. Sawyer (1980), Experimental study of the flow field of a two-dimensional premixed turbulent flame, AIAA Journal, 18, No 7, 817-824.
10) Hegde, U.G., D. Reuter, and B. T.Zinn (1989), Variable geometry control of reacting shear layers, AIAA-89-0979.
11) Keller, J.O., L. Vaneveld, D. Korschelt, G.L. Hubbard, A.F. Ghoniem, J.W. Daily and A.K. Oppenheim (1982), Mechanism of instabilities in turbulent combustion leading to flashback, AIAA Journal, 20, No. 2, 254-262.
12) Langhorne, P.J. (1988), Reheat buzz: acoustically coupled combustion instability. Part 1. Experiment, Journal of Fluid Mechanics, 193, 417-443.
13) Lieuwen, T.C. and B.T. Zinn (2000), On the experimental determination of combustion process driving in an unstable combustor, Combustion Science and Technology, 157, 111-127.
14) Menon, S. (1992), Active combustion control in a ramjet using large eddy simulations, Combustion Science and Technology, 84, 51-79.
15) Najm, H.N., and A.F. Ghoniem (1994), Coupling between vorticity and pressure oscillations in combustion instability, Journal of Propulsion and Power, 10, No. 6, 769-776.
16) Renard, P-H., J.C. Rolon, D.T. Venin, and S. Candel (1999), Investigations of heat release, extinction, and time evolution of the flame surface, for a non-premixed flame interacting with a vortex, Combustion and Flame, 117, 189-205.
17) Smith, D.A. and E.E. Zukoski (1985), Combustion instability sustained by unsteady vortex combustion, AIAA-85-1248.
18) Thangam, S. and N. Hur (1991), A highly-resolved numerical study of turbulent separated flow past a backward-facing step, International Journal of Engineering Science, 29, 607-615.
The instantaneous and average velocity fields for both cold and combusting flows have been obtained using CFD package FLUENT.