Thermochemical exploration of hydrogen combustion in generic scramjet combustor

J. Inst. Eng. India Ser. C

2016

Self Cite

The flow field of a Liquid Fuel Ram Jet engine side dump combustor with kerosene fuel is numerically simulated using commercial CFD code CFX-11. Reynolds Averaged 3-D Navier-Stokes equations are solved alongwith SST turbulence model. Single step infinitely fast reaction is assumed for kerosene combustion. The combustion efficiency is evaluated in terms of the unburnt kerosene vapour leaving the combustor. The comparison of measured pressures with computed values show that the computation underpredicts (*5 %) pressures for non reacting cases but overpredicts (9-7 %) for reacting cases.

Section: Resultsmentioning

confidence: 99%

Section: Governing Equations and Modelsmentioning

confidence: 93%

Numerical Simulations of Static Tested Ramjet Dump Combustor

Javed

J. Inst. Eng. India Ser. C

2016

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“…The fluctuation in the flow field caused by turbulence can significantly alter the oxidiser and fuel distribution and hence reaction process. Number of validation studies carried out by the present authors [24][25][26][27] demonstrated that standard two equation class turbulence model with single step kinetics based turbulence chemistry interaction can describe H 2 -air reaction adequately in high speed flows. In this paper, Chang et al experiment [22,23] is numerically explored with both laminar chemistry and single step kinetics based combustion model to study the effect of turbulence chemistry interaction in high speed H 2 -air reacting flow.…”

Section: Introductionmentioning

confidence: 97%

“…Simultaneous measurement of temperature and species concentration in high speed reacting flow has made the Cheng et al [22,23] experiment very special in supersonic reacting code validation and many authors [18,[24][25][26][27][28][29][30] has taken this experiment a validation case for their numerical studies. In the experiment of Cheng et al [22,23], a pure hydrogen jet is injected at sonic speed into a vitiated supersonic (M a = 2) coflow.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Hydrogen Air Supersonic Coaxial Jet

Dharavath

Manna

J. Inst. Eng. India Ser. C

2016

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In the present study, the turbulent structure of coaxial supersonic H 2 -air jet is explored numerically by solving three dimensional RANS equations along with two equation k-e turbulence model. Grid independence of the solution is demonstrated by estimating the error distribution using Grid Convergence Index. Distributions of flow parameters in different planes are analyzed to explain the mixing and combustion characteristics of high speed coaxial jets. The flow field is seen mostly diffusive in nature and hydrogen diffusion is confined to core region of the jet. Both single step laminar finite rate chemistry and turbulent reacting calculation employing EDM combustion model are performed to find the effect of turbulencechemistry interaction in the flow field. Laminar reaction predicts higher H 2 mol fraction compared to turbulent reaction because of lower reaction rate caused by turbulence chemistry interaction. Profiles of major species and temperature match well with experimental data at different axial locations; although, the computed profiles show a narrower shape in the far field region. These results demonstrate that standard two equation class turbulence model with single step kinetics based turbulence chemistry interaction can describe H 2 -air reaction adequately in high speed flows.

“…The details of the governing equations, thermodynamics and the discretization schemes are given in the following subsections. To find out the accuracy and the range of applications, the software has been validated for various reacting and non-reacting flows pertaining to the scramjet combustor including transverse sonic injection in a supersonic flow 12 , transverse H 2 injection in constant area duct 13 , H 2 injection from struts 14,15 and pylon injectors 16 . All these validation exercises have revealed that although the computed pressures overpredict the experimental values in the injection zone, the computational and experimental values of the flow parameters match fairly well in the divergent portion of the combustor where the major portion of thrust is produced.…”

Section: Experimental Set-up For Carrying Out Computationsmentioning

confidence: 99%

N umerical Investigation of Hydrogen-fuelled Scramjet Combustor with Cavity Flame Holder

Dharavath

Manna

2014

DSJ

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Reacting flow field of a cavity-based hydrogen-fuelled supersonic combustion ramjet (scramjet) combustor has been explored numerically. 3-D RANS equations are solved alongwith k-ε turbulence model and infinitely fast rate kinetics for combustion. The flow field inside the flame holding cavity and its effect on the mixing and reaction are explored in detail by performing simulations of two different combustors (with and without cavities) for which elaborate surface pressure measurements are available for reacting and non-reacting flows. Simulations capture all the finer details of the flow field and good match between computed surface pressures experimental values for different equivalence ratios forms the basis of further analysis. The cavity of the combustor behaves as an open cavity for both non-reacting and reacting flow-even though the flow patterns inside the cavity are quite different for both the cases. Flame-holding cavities are seen to augment mixing and reaction in small sized combustors.