Radiative interactions in supersonic flows of premixed hydrogen in expanding nozzles

Tiwari, S. N.; Pidugu, Srikanth B.; Mohieldin, T.

doi:10.2514/6.1999-1052

“…Previous works have looked at the radiative transport in a supersonic system and have found the radiative contribution to range from less than 10% to more than 90% of the total heat flux to the wall. [5][6][7] However, these findings are based on systems with greatly different flow-fields and geometries from those used in the HyShot II tests. Previous works show that radiative heat loss in a jet combustion chamber can lead to variations in flame properties, but these focus on flames with different chemical compositions and much slower flow speeds than those found in the HyShot II experiment.…”

Section: Introductionmentioning

confidence: 99%

Radiation Modeling of a Hydrogen Fueled Scramjet

Crow

¹

,

Boyd

²

,

Terrapon

³

2013

Journal of Thermophysics and Heat Transfer

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With the difficulty and cost of full-scale flight experiments, the design of scramjet engines relies heavily on computational simulations. Radiation may play an important role in wall heating and flow cooling of scramjets. However, very few studies have focused on such. The present analysis is based on three-dimensional turbulent reacting flow simulations of the HyShot II hydrogen fueled scramjet engine running at flight conditions of Mach 7.4. A one-dimensional Discrete Ordinates Method analysis with a narrow band averaged spectral model is employed to determine wall heating and flow cooling from thermal radiation. The one-dimensional Discrete Ordinates Method is verified against a three-dimensional ray tracing method. The radiative species considered are H2O and OH. The radiative heat flux is on the order of 10 kW/m 2 , which is 0.1-0.2% of the total convective wall heat flux. Flow cooling due to radiation is found to be on the order of 2 K. Sensitivity analysis shows that radiation is highly dependent on chamber size, temperature, pressure and radiative species mole fraction. Variations in these factors can explain the differences between previous analyses in the literature that studied hypothetical engines and the current work that models an existing scramjet.

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“…Previous works have looked at the radiative transport in a supersonic system and have found the radiative contribution to range from less than 10% to more than 90% of the total heat flux to the wall. [5][6][7] However, these findings are based on systems with greatly different flow-fields and geometries from those used in the HyShot II tests. Previous works show that radiative heat loss in a jet combustion chamber can lead to variations in flame properties, but these focus on flames with different chemical compositions and much slower flow speeds than those found in the HyShot II experiment.…”

Section: Introductionmentioning

confidence: 99%

Radiation Modeling of a Hydrogen-Fueled Scramjet

Crow

¹

,

Boyd

²

,

Terrapon

³

2011

42nd AIAA Thermophysics Conference

5

0

View full text Add to dashboard Cite

With the difficulty and cost of full-scale flight experiments, the design of scramjet engines relies heavily on computational simulations. Radiation may play an important role in wall heating and flow cooling of scramjets. However, very few studies have focused on such. The present analysis is based on three-dimensional turbulent reacting flow simulations of the HyShot II hydrogen fueled scramjet engine running at flight conditions of Mach 7.4. A one-dimensional Discrete Ordinates Method analysis with a narrow band averaged spectral model is employed to determine wall heating and flow cooling from thermal radiation. The one-dimensional Discrete Ordinates Method is verified against a three-dimensional ray tracing method. The radiative species considered are H2O and OH. The radiative heat flux is on the order of 10 kW/m 2 , which is 0.1-0.2% of the total convective wall heat flux. Flow cooling due to radiation is found to be on the order of 2 K. Sensitivity analysis shows that radiation is highly dependent on chamber size, temperature, pressure and radiative species mole fraction. Variations in these factors can explain the differences between previous analyses in the literature that studied hypothetical engines and the current work that models an existing scramjet.

show abstract