The a-priori prediction of high frequency combustion instability will certainly favorably impact on the development costs of new liquid propellant rocket engines. Achieving such objective with a reduced order model implies a significant reduction of the experimental efforts and costs as well as of the massive high-fidelity numerical simulations which are mandatory in order to investigate this issue.
An in-house quasi-1D Eulerian solver for multispecies employing an n-tau heat release rate to acoustics coupling function has been developed to face longitudinal high-frequency instability problems. Such class of solvers need the strict link between the acoustics to the unsteady heat release rate, in terms of timing (tau) and intensity (n) to be known and given as input.
The main goal of the proposed research is to achieve the capability to predict such strict coupling and therefore giving to the solver the proficiency of predicting combustion instability occurrence starting only from the geometry of the chamber and from the chemical features of the propellants.
Nowadays, high-frequency combustion instability is not predictable. Several examples are available in literature in which large CFD simulations struggle to predict its intensity or even occurrence, as explained in the previous sections. In this sense, developing any predictive tool will assure a step forward with respect to the current state of the art. Moreover, the proposers are looking for a tool which has to be as simple and convenient as possible, and capable of giving a rapid evaluation (even approximated) on the acoustic stability features of a system.
Instability is unfortunately usually detected at the moment of the full-scale tests, yielding both to severe delays and to the addition of extra costs to the project schedule. When such scenario occurs, the only feasible solution is to modify the engine by adding some baffle or damping device, even if this reduces the performances of the engine significantly.
Achieving the above explained predictive capability by means of a fast and cheap tool of the described kind will be an important scientific result for two main reasons. The former is that the combustion instability a-priori prediction is something not yet realized, to our knowledge. The latter is that the proposed research will provide a useful tool to determine the stability features of a new engine within the design schedule.
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>> References
[1] J. C. Oefelein and V. Yang. Comprehensive review of liquid-propellant combustion instabilities in F-1 engines. J Prop Power, 9(5), Sep-Oct, 1993.
[2] F. E. C. Culick and V. Yang. Combustion instabilities in liquid rockets. Liquid Rocket Engine Combustion Instability, 169, AIAA, pp.3-37, 1995.
[3] S. Groning, J. S. Hardi, D. Suslov, and M. Oschwald. Analysis of phase shift between oscillations of pressure and flame radiation intensity of self-excited combustion instabilities. 6th European Conference for Aeronautics and Space Sciences, Jun 29 - Jul 3, 2015, Krakow, Poland.
[4] S. Groning, D. Suslov, J. S. Hardi, and M. Oschwald. Influence of hydrogen temperature on the acoustics of a rocket engine combustion chamber operated with LOX/H2 at representative conditions. Space Propulsion Conference, May 2014, Germany.
[5] S. Groning, D. Suslov, M. Oschwald, and T. Sattelmayer. Stability behaviour of a cylindrical rocket engine combustion chamber operated with liquid hydrogen and liquid oxygen. 5th European Conference for Aeronautics and Space Sciences, Jul 2013, Germany.
[6] J. S. Hardi, M. Oschwald, and B. B. Dally. Study of LOX/H2 spray flame response to acoustic excitation in a rectangular rocket combustor. 49th AIAA/ASME/SAE/ASEE
Joint Propulsion Conference, Jul 2013, CA.
[7] M. E. Harvazinski, C. Huang, V. Sankaran, T. W. Feldman, W. E. Anderson, C. L. Merkle, and D. G. Talley. Coupling between hydrodynamics, acoustics and heat release in a self-excited unstable combustor. Physics of Fluids, 27, 045102, 2015.
[8] K. Miller, J. C. Sisco, N. Nugent, and W. E. Anderson. Combustion instability with a single-element swirl injector. J Prop Power, 23, pp. 1102-1112, 2007.
[9] Y. C. Yu, J. C. Sisco, W. E. Anderson, and V. Sankaran. Examination of spatial mode shapes and resonant frequencies using linearized Euler solutions. 2007. 37th AIAA Fluid Dynamich Conference & Exhibit, 25-28 Jun, FL.
[10] M. L. Dranovsky. Combustion Instabilities in Liquid Rocket Engines. Testing and Development Practices in Russia. V. Yang, F. E. Culick, D. G. Talley, Prog in Aeron and Astron.
[11] S. C. Fisher, F. E. Dodd, and R. J. Jensen. Scaling techniques for liquid rocket combustion stability testing. In V. Yang and W. E. Anderson ed, Liquid Rocket Engine Combustion Instability, 169, Prog in Aeron and Astron, ch 21, pp.545-564. AIAA, 1995.
[12] Y. C. Yu. Experimental and analytical Investigations of Longitudinal Combustion Instability
in a Continuously Variable Resonance Combustor (CVRC). PhD th, Purdue University,
School of Aeron and Astron, 2009.
[13] Y. C. Yu, S. M. Koeglmeier, J. C. Sisco, R. J. Smith, and W. E. Anderson. Combustion instability of gaseous fuels in a continuously variable resonance chamber (cvrc). 2008. 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, Jul, CT.
[14] Y. C. Yu, J. C. Sisco, S. Rosen, A. Madhav, and W. E. Anderson. Spontaneous longitudinal combustion instability in a continuously-variable resonance combustor. J Prop Power, 28, pp. 876-887, 2012.
[15] Brian Pomeroy and William Anderson. Transverse instability studies in a subscale chamber. J Prop Power, 32(4):939-947, 2016.
[16] M. E. Harvazinski, W. E. Anderson, and C. L. Merkle. Analysis of self-excited combustion instability using two- and three-dimensional simulations. J. Prop. Power,
Vol. 29, pp. 396-409, 2013.