Porous versus porthole fuel injection in a radical farming scramjet: A numerical analysis

Numerically computed engine performance of a nominally two-dimensional radical farming scramjet with porous (permeable C/C ceramic) and porthole fuel injection is presented. Inflow conditions with Mach number, stagnation pressure, and enthalpy of 6.44, 40.2MPa, and 4.31 MJ/kg respectively, and fuel/air equivalence ratio of 0.44 were maintained, along with engine geometry. Hydrogen fuel was injected at an axial location of 92.33mm downstream of the leading edge for each investigated injection method. Results from this study show that porous fuel injection results in enhanced mixing and combustion compared to porthole fuel injection. This is particularly evident within the first half of the combustion chamber where porous fuel injection resulted in mixing and combustion efficiencies of 76% and 63% respectively. At the same location, porthole fuel injection resulted in efficiencies respectively of 58% and 46%. Key mechanisms contributing to the observed improved performance were the formation of an attached oblique fuel injection shock and associated stronger shock-expansion train ingested by the engine, enhanced spreading of the fuel in all directions and a more rapidly growing mixing layer.

[1]  Russell R. Boyce,et al.  Simulations of mixing in an inlet-fueled axisymmetric scramjet , 2013 .

[2]  C. Park,et al.  Nonequilibrium Hypersonic Aerothermodynamics , 1989 .

[3]  Scott A. Berry,et al.  Comparison of Methods for Determining Boundary Layer Edge Conditions for Transition Correlations , 2003 .

[4]  Corin Segal,et al.  The Scramjet Engine: Contents , 2009 .

[5]  Shelly M. Ferlemann,et al.  Hyper-X Mach 7 Scramjet Design, Ground Test and Flight Results , 2005 .

[6]  Corin Segal,et al.  The Scramjet Engine: List of Acronyms , 2009 .

[7]  Adrian S. Pudsey,et al.  Influence of common modeling choices for high-speed transverse jet-interaction simulations , 2013 .

[8]  K. Hannemann,et al.  Experiments on passive hypersonic boundary layer control using ultrasonically absorptive carbon–carbon material with random microstructure , 2013 .

[9]  Allan Paull,et al.  Radical Farming in Scramjets , 2007 .

[10]  Judy Odam,et al.  Scramjet Experiments using Radical Farming , 2004 .

[11]  F. S. Billig,et al.  Penetration of gaseous jets injected into a supersonic stream. , 1966 .

[12]  Johan Steelant,et al.  Comparison of Two Permeation Test Benches and of Two Determination Methods for Darcy's and Forchheimer's Permeabilities , 2012 .

[13]  Allan Paull,et al.  Investigation of an intake injected hot-wall scramjet , 2004 .

[14]  M. R. Gruber,et al.  Mixing and Penetration Studies of Sonic Jets in a Mach 2 Freestream , 1995 .

[15]  Chung King Law,et al.  Chemical Kinetics and Self-Ignition in a Model Supersonic Hydrogen-Air Combustor , 1999 .

[16]  Edward E. Zukoski,et al.  Secondary injection of gases into a supersonic flow , 1964 .

[17]  Allan Paull,et al.  Upstream porthole injection in a 2-D scramjet model , 2002 .

[18]  Russell R. Boyce,et al.  3D separations within the SCRAMSPACE I hypersonic flight experiment scramjet , 2012 .

[19]  Russell R. Boyce,et al.  Radical farm ignition processes in two-dimensional supersonic combustion , 2008 .

[20]  Russell R. Boyce,et al.  Hypersonic Viscous Drag Reduction via Multiporthole Injector Arrays , 2013 .

[21]  J. Driscoll,et al.  Combustion Efficiencies of Supersonic Flames , 2001 .

[22]  Bianca R. Capra,et al.  A detailed investigation of nominally 2-D radical-farming scramjet combustion , 2012 .

[23]  Allan Paull,et al.  Scramjets and shock tunnels—The Queensland experience , 2005 .

[24]  Graham V. Candler,et al.  Development of a hybrid unstructured implicit solver for the simulation of reacting flows over complex geometries , 2004 .

[25]  J. Wolfersdorf,et al.  Experimental Investigations on Transpiration Cooling for Scramjet Applications Using Different Coolants , 2011 .

[26]  Harold Pergament,et al.  A THEORETICAL ANALYSIS OF NON-EQUILIBRIUM HYDROGEN-AIR REACTIONS IN FLOW SYSTEMS , 1963 .

[27]  Robert A. Baurle,et al.  Extraction of One-Dimensional Flow Properties from Multidimensional Data Sets , 2008 .

[28]  Joseph A. Schetz,et al.  Detailed flow physics of the supersonic jet interaction flow field , 2009 .

[29]  L. Brown,et al.  Supersonic Combustion Processes in a Premixed Three-Dimensional Nonuniform-Compression Scramjet Engine , 2014 .

[30]  Paul Ferlemann.  Hyper-X Mach 10 Scramjet Preflight Predictions and Flight Data , 2005 .