Numerical investigation of the supersonic combustion of kerosene in a strut-based combustor
01 Sep 2010-Journal of Propulsion and Power (American Institute of Aeronautics and Astronautics Inc. (AIAA))-Vol. 26, Iss: 5, pp 1084-1091
TL;DR: In this paper, a simulation of the supersonic combustion of liquid kerosene in a strut-based combustor was carried out, where three-dimensional compressible, turbulent, nonreacting and reacting flow calculations with a single-step chemistry model have been carried out.
Abstract: In this numerical study, supersonic combustion of liquid kerosene in a strut-based combustor is investigated. To this end, three-dimensional compressible, turbulent, nonreacting and reacting flow calculations with a single-step chemistry model have been carried out. For the nonreacting flow calculations, fuel droplet trajectories, degree of mixing,andmixingefficiencyarepresentedanddiscussed.Forthereacting flowcalculations,contoursofheatrelease and Mach number and the variation of combustion efficiency, total pressure loss, and thrust profile along the combustor length are used to identify the regions of mixing and heat release inside the combustor. Furthermore, the predicted variation of static pressure along the combustor top wall is compared with experimental data. The significance of the lateral spread of the fuel and the extent of the mixing process, especially for a liquid fuel such as kerosene, on the prediction of heat release is discussed in detail.
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TL;DR: In this paper, the authors present a review of the research progress made on supersonic combustors equipped with struts in recent decades, including fuel injection and mixing enhancement, thermal protection, strut resistance characteristics, combustion stabilization mechanisms, and flame propagation processes.
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TL;DR: In this article, the effect of strut lip height, staggered strut and the strut position relative to the combustor entrance on the combustion enhancement of a two-strut scramjet combustor was analyzed.
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TL;DR: In this paper, the authors address the problems encountered when modeling high-speed combustion, or in other words, what are the problems of turbulent-combustion modeling? Do such interactions need modeling? What are the challenges when going from modeling low-speed-to-high-speed combustions problems?
84 citations
TL;DR: In this article, the influence of the radius of the strut tip, the half-angle and the strut location relative to the combustor entrance on the combustion performance of a combustor has been discussed.
Abstract: The Reynolds averaged Navier-Stokes (RANS) equations coupled with the renormalization group (RNG) k-e and the single-step chemical reaction mechanism have been used to evaluate the influence of the radius of the strut tip, the half-angle of the strut and the strut location relative to the combustor entrance on the combustion performance of the combustor has been discussed. At the same time, the numerical method has been validated by the available experimental shadowgraph, velocity measurements and temperature measurements in the open literature. With the increasing of the radius of the strut tip, the separation region generated due to the strong interaction between the shock wave and the boundary layer becomes broader, and accordingly, a bifurcated shock wave appears at the front of the strut, then a shock wave train. The shock waves generated at the intersectional points between the walls of the strut and the sonic lines play an important role in the generation of the separation zone, and they can improve the combustion efficiency to a certain extent. Further, the mixing process is more intensive than the chemical reaction process in the vicinity of the strut base, and the combustion efficiency increases nearly monotonically with the increasing of the horizontal distance in the range considered in the current study. When the intersectional point between the leading shock wave and the upper wall overlaps with the divergence point, the combustion efficiency at the exit of the combustor becomes the largest, and its value is nearly 96.2%.
83 citations
References
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01 Jun 1978TL;DR: In this paper, the authors evaluated the applicability of the standard κ-ϵ equations and other turbulence models with respect to their applicability in swirling, recirculating flows.
Abstract: The standard κ-ϵ equations and other turbulence models are evaluated with respect to their applicability in swirling, recirculating flows. The turbulence models are formulated on the basis of two separate viewpoints. The first perspective assumes that an isotropic eddy viscosity and the modified Boussinesq hypothesis adequately describe the stress distributions, and that the source of predictive error is a consequence of the modeled terms in the κ-ϵ equations. Both stabilizing and destabilizing Richardson number corrections are incorporated to investigate this line of reasoning. A second viewpoint proposes that the eddy viscosity approach is inherently inadequate and that a redistribution of the stress magnitudes is necessary. Investigation of higher-order closure is pursued on the level of an algebraic stress closure. Various turbulence model predictions are compared with experimental data from a variety of isothermal, confined studies. Supportive swirl comparisons are also performed for a laminar flow case, as well as reacting flow cases. Parallel predictions or contributions from other sources are also consulted where appropriate. Predictive accuracy was found to be a partial function of inlet boundary conditions and numerical diffusion. Despite prediction sensitivity to inlet conditions and numerics, the data comparisons delineate the relative advantages and disadvantages of the various modifications. Possible research avenues in the area of computational modeling of strongly swirling, recirculating flows are reviewed and discussed.
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TL;DR: In this paper, a comprehensive model of high temperature hydrocarbon oxidation in combustion is presented, with emphasis on the hierarchical structure of reaction mechanisms for complex fuels, including both inhibition and promotion of combustion.
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...Rate data for the C12H23 O2 forward reaction mechanism has been adapted from Westbrook and Dryer [16]....
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TL;DR: In this paper, Reynolds averaged Navier-Stokes calculations have been performed for a U.S. Air Force Research Laboratory/ Aerospace Propulsion Ofe ce scramjet combustor designed for Mach 4.0 ‐6.5 e ight.
Abstract: Reynolds averaged Navier ‐Stokes calculations have been performed for a U.S. Air Force Research Laboratory/ Aerospace Propulsion Ofe ce scramjet combustor designed for Mach 4.0 ‐6.5 e ight. The combustor e owpath is unique in that it is entirely free of e ow obstructions with fuel injection from wall-mounted injection ports and e ameholding established by means of a recessed cavity. Calculations were performed at the minimum (Mach 4.0) andmaximum(Mach6.5)e ightdesign conditions.Thecombustoroperatedin dualmodeattheMach4.0condition. The precombustion shock train formed a region of low-momentum/separated e ow adjacent to the combustor side wall. This proved to be a primary source of e ameholding, with the recessed cavity adding additional e ameholding support. The e ow was notthermally choked at theMach 6.5 condition,resulting in very little upstream interaction. The mixing process at the Mach 4.0 e ight condition was considerably more efe cient than that seen at the Mach 6.5 condition, due primarily to the shock-induced e ow distortion and larger residence time. Even with the reduced mixing levels predicted at the Mach 6.5 condition, the combustion efe ciency was comparable to that achieved at the Mach 4.0 condition. The solutions obtained for dual-mode operation were particularly sensitive to choice of turbulence model and values specie ed for the turbulent Prandtl and Schmidt numbers. Overall, the solution sensitivity to grid resolution was small relative to the solution sensitivity to modeling uncertainties.
131 citations
13 Jul 1998
TL;DR: In this article, pre-test computational fluid dynamics (CFD) data have been generated for an experimental scramjet combustor concept, which represents the first step of a research initiative at Wright-Patterson Air Force Base that combines state-of-theart experimental facilities with CFD towards the development of scramjet propulsion technologies.
Abstract: Pre-test computational fluid dynamics (CFD) data have been generated for an experimental scramjet combustor concept. These calculations represent the first step of a research initiative at Wright-Patterson Air Force Base that combines state-of-the-art experimental facilities with CFD towards the development of scramjet propulsion technologies. Both cold flow and reacting simulations have been performed for a baseline combustor pilot concept that consists of a wall mounted fuel injection system combined with a cavity flameholder. Results show reasonable mixing levels with minimal total pressure losses. Reacting simulations have shown that further refinements are needed to the combustor geometry to prevent thermal choking under certain conditions. Data obtained from CFD have proven beneficial to the experimental program by directing tests towards evaluating potential problems revealed by the calculations. Preliminary comparisons with measurements were favorable.
129 citations
"Numerical investigation of the supe..." refers background or methods in this paper
...In the present work, this is evaluated using a mixing efficiency [17], which is defined as follows:...
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...Combustion efficiency on a given x constant plane is given as [17]...
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TL;DR: In this article, the influence of chemistry models on the predictions of supersonic combustion in a model combustor is investigated, and the results show that multi-step chemistry predicts higher and more wide spread heat release than what is predicted by single step chemistry.
117 citations
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...Moreover, a detailed chemistry model can also be beneficial in view of the fact that heat release is higher with a detailed chemistry model [18]....
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