Experimental Investigations on Supersonic Stream Past Axisymmetric Cavities

Jeyakumar, S.; Balachandran, P.; Indira, S.

doi:10.2514/1.21024

Cited by 14 publications

(5 citation statements)

References 12 publications

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“…These nozzles, however, cause a higher loss of stagnation pressure than standard nozzles. Jeyakumar et al 17 demonstrated that the mixing efficiency of coaxial jets could be enhanced using the tandem cavities at a marginal rise in stagnation pressure loss. Byun et al 18 developed a new correlation method to determine the pre-combustion shock train length and the combustion performance of the DCR engine.…”

Section: Aeronautical Engineering Kalasalingam Academy Of Research An...mentioning

confidence: 99%

The non-reacting flow characteristics of pylon and wall injections in a dual combustion ramjet engine

Sebastin

Jeyakumar

Karthik

2021

International Journal of Engine Research

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The influence of pylon and wall injection in coaxial jets of a Dual Combustion Ramjet engine is numerically investigated in a non-reacting flow field. The supersonic combustor is modeled and analyzed using the commercial CFD software ANSYS 18.0. The three-dimensional compressible Reynolds-averaged Navier-Stokes (RANS) equations coupled with the SST k-ω turbulence model have been used to analyze the coaxial mixing characteristics of the jets. The numerical study is validated with the experimental data of the wall static pressures measured in the combustor’s flow direction. The pylon and wall injectors are located symmetrically at the gas generator’s exit nozzle, and the air is used as the injectant to simulate gaseous fuel. Three injection pressures are used for the study to understand the flow field characteristics in the injector regime. Also, the gas generator downstream direction is investigated. The shock waves generated from the gas generator nozzle enhance the mixing of the coaxial jets with minimum total pressure loss. The shock wave interactions are noticed with reducing intensity within the supersonic combustor for pylon injection, leading to higher total pressure loss than the wall injection. The pylon injection provides the spatial distribution of fuels compared to the wall injection in the coaxial supersonic flow field.

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Section: Aeronautical Engineering Kalasalingam Academy Of Research An...mentioning

confidence: 99%

The non-reacting flow characteristics of pylon and wall injections in a dual combustion ramjet engine

Sebastin

Jeyakumar

Karthik

2021

International Journal of Engine Research

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“…An efficient fuel injection system necessitates for complete combustion of hydrogen fuel in the scramjet combustor, which could enhance the mixing and combustion of fuel and air with minimum total pressure loss. Various injection and flame holding strategies such as flush wall injection (Goyne et al, 2001;Tahani et al, 2016), cavities (Assis et al, 2019;Jeyakumar et al, 2006Jeyakumar et al, , 2017Jeyakumar et al, , 2018Wang et al, 2020), pylons (Doster et al, 2007;Gruber et al, 2008;Lee, 2012) and struts (Bresson et al, 2001;Huang et al, 2017;Liu et al, 2019) and their combinations (Freeborn et al, 2009;Lakka et al, 2021;Montes et al, 2005;Suneetha et al, 2019aSuneetha et al, , 2019b were attempted and succeeded to some extend by many researchers. A strut-based injector configuration is among the ones that could solve the aforementioned issues and also limit the total pressure loss.…”

Section: Introductionmentioning

confidence: 99%

Numerical investigations on the hydrogen jet pressure variations in a strut based scramjet combustor

Jeyakumar

Jayaraman

Sivakumar

et al. 2021

AEAT

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Purpose This paper aims to study the influences of hydrogen jet pressure on flow features of a strut-based injector in a scramjet combustor under-reacting cases are numerically investigated in this study. Design/methodology/approach The numerical analysis is carried out using Reynolds Averaged Navier Stokes (RANS) equations with the Shear Stress Transport k-ω turbulence model in contention to comprehend the flow physics during scramjet combustion. The three major parameters such as the shock wave pattern, wall pressures and static temperature across the combustor are validated with the reported experiments. The results comply with the range, indicating the adopted simulation method can be extended for other investigations as well. The supersonic flow characteristics are determined based on the flow properties, combustion efficiency and total pressure loss. Findings The results revealed that the augmentation of hydrogen jet pressure via variation in flame features increases the static pressure in the vicinity of the strut and destabilize the normal shock wave position. Indeed, the pressure of the mainstream flow drives the shock wave toward the upstream direction. The study perceived that once the hydrogen jet pressure is reached 4 bar, the incoming flow attains a subsonic state due to the movement of normal shock wave ahead of the strut. It is noticed that the increase in hydrogen jet pressure in the supersonic flow field improves the jet penetration rate in the lateral direction of the flow and also increases the total pressure loss as compared with the baseline injection pressure condition. Practical implications The outcome of this research provides the influence of fuel injection pressure variations in the supersonic combustion phenomenon of hypersonic vehicles. Originality/value This paper substantiates the effect of increasing hydrogen jet pressure in the reacting supersonic airstream on the performance of a scramjet combustor.

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“…A robust flame holding mechanism is needed owing to the short residence time of airflow in the scramjet combustor. There are various injection and flame holding mechanisms, such as cavities [4][5][6][7][8][9][10], pylons [11][12][13][14] and struts [15][16][17][18][19][20][21][22][23][24][25][26][27][28]. The combinations of the aforementioned schemes [29][30][31][32] were succeeded to some extend by several studies.…”

Section: Introductionmentioning

confidence: 99%

The Combustion Characteristics of Double Ramps in a Strut-Based Scramjet Combustor

et al. 2021

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This paper focuses on the influence of ramp locations upstream of a strut-based scramjet combustor under reacting flow conditions that are numerically investigated. In contrast, a computational study is adopted using Reynolds Averaged Navier Stokes (RANS) equations with the Shear Stress Transport (SST) k-ω turbulence model. The numerical results of the Deutsches Zentrum für Luft- und Raumfahrt or German Aerospace Centre (DLR) scramjet model are validated with the reported experimental values that show compliance within the range, indicating that the adopted simulation method can be extended for other investigations as well. The performance of the ramps in the strut-based scramjet combustor is analyzed based on parameters such as wall pressures, combustion efficiency and total pressure loss at various axial locations of the combustor. From the numerical shadowgraph, more shock interactions are observed upstream of the strut injection region for the ramp cases, which decelerates the flow downstream, and additional shock reflections with less intensity are also noticed when compared with the DLR scramjet model. The shock reflection due to the ramps enhances the hydrogen distribution in the spatial direction. The ignition delay is noticed for ramp combustors due to the deceleration of flow compared to the baseline strut only scramjet combustor. However, a higher flame temperature is observed with the ramp combustor. Because more shock interactions arise from the ramps, a marginal increase in the total pressure loss is observed for ramp combustors when compared to the baseline model.

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Experimental Investigations on Supersonic Stream Past Axisymmetric Cavities

Cited by 14 publications

References 12 publications

The non-reacting flow characteristics of pylon and wall injections in a dual combustion ramjet engine

The non-reacting flow characteristics of pylon and wall injections in a dual combustion ramjet engine

Numerical investigations on the hydrogen jet pressure variations in a strut based scramjet combustor

The Combustion Characteristics of Double Ramps in a Strut-Based Scramjet Combustor

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