Supersonic combustion of hydrogen using an improved strut injection scheme

Aravind, S.; Kumar, Rajiv

doi:10.1016/j.ijhydene.2019.01.064

Cited by 67 publications

(12 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Simple struts have been used to successfully increase fuel plume penetration (6,7) . Addition of vortex generating shapes to the struts also produces a substantial increase in mixing rate (8,9) . As an example, the work by Aravind (8) shows a lobbed strut reduces the distance to 95% mixing efficiency by about half at the cost of an increase in about 30% in total pressure over a simple strut at Mach 2.0.…”

Section: Introductionmentioning

confidence: 99%

“…Addition of vortex generating shapes to the struts also produces a substantial increase in mixing rate (8,9) . As an example, the work by Aravind (8) shows a lobbed strut reduces the distance to 95% mixing efficiency by about half at the cost of an increase in about 30% in total pressure over a simple strut at Mach 2.0. Ramps have shown improvement in penetration and mixing by producing vortical structures that interact with the injected fuel.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of scramjet inlet vortices on fuel plume elongation and mixing rate

2019

View full text Add to dashboard Cite

Hypersonic air-breathing propulsion can improve cost and flexibility of Low Earth Orbit (LEO) satellite launch missions. However, at the high flight Mach numbers required for access-to-space, performance margins are extremely tight. Techniques to improve mixing efficiency can push this technology forward. However, these are required to produce a minimal increase in losses and heat loads to be viable. The use of inlet-generated vortices in scramjets for mixing enhancement was previously studied. These vortices interact with the injected fuel plume, stretching it and increasing its effective surface for mixing. Moreover, these vortices are intrinsic to the flowfield. Therefore, contrary to other methods, when using inlet vortices mixing is enhanced without producing additional heat loads or losses. This work studies the vortex-injection interaction through numerical RANS simulations. A non-dimensional variable defining the quality of the plume shape for mixing purposes is proposed. This parameter is used to assess the effect of vortex intensity and injector location on fuel plume shape. The results show the ability of inlet vortices to modify fuel plume shape significantly increasing fuel mixing rate with minimal impact on losses.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of scramjet inlet vortices on fuel plume elongation and mixing rate

2019

View full text Add to dashboard Cite

show abstract

“…The model transport equation called the Shear Stress Transport (SST) k-ω model [15,48,49] with default constants was used for solving the turbulent flow field. The SST k-ω turbulence model provides a good prediction of mixing layers and jet flows [18,19,29]. The flow is considered to be ideal gas, and the thermal conductivity and viscosity are computed using mass-weighted-mixing-law.…”

Section: Methodsmentioning

confidence: 99%

“…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

View full text Add to dashboard Cite

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.

show abstract

“…49 The turbulence model provides a good prediction of mixing layers and jet flows. 51 The flow is considered to be ideal gas, and the thermal F I G U R E 1 Schematic layout of the 2D combustor model conductivity and viscosity are computed using mass-weighted-mixing law. 52 The Courant-Friedrichs-Lewy (CFL) number is chosen as 0.5 under the relevant relation factor to ensure stability.…”

Section: Numerical Flow Modeling and Simulationmentioning

confidence: 99%

Numerical investigations on the performance of a multistrut hydrogen injector in a scramjet combustor

2021

View full text Add to dashboard Cite

This study aims at investigating the effect of a multistrut-based hydrogen injector in a scramjet combustor underreacting case. The numerical analysis is carried out using two-dimensional Reynolds-averaged Navier-Stokes 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 experimental results. The results comply with the range, indicating that the adopted simulation method for single strut injection can be extended for other investigations. It is noticed that with multistrut injectors, as hydrogen jet pressure increases in the supersonic flow field, the jet penetration rate in the lateral direction of the flow and the total pressure loss as compared with the baseline injection pressure conditions has increased. The supersonic flow characteristics are determined based on the flow properties, combustion efficiency, mixing efficiency, and total pressure loss. Compared with the single-strut output of a scramjet combustor, multistruts inclusion increased the combustion efficiency by almost 18%, the mixing efficiency attained the maximum with 16% fewer lengths. The total pressure loss in single-strut is 14% lower than that of multistrut.

show abstract

Supersonic combustion of hydrogen using an improved strut injection scheme

Cited by 67 publications

References 35 publications

Effect of scramjet inlet vortices on fuel plume elongation and mixing rate

Effect of scramjet inlet vortices on fuel plume elongation and mixing rate

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

Numerical investigations on the performance of a multistrut hydrogen injector in a scramjet combustor

Contact Info

Product

Resources

About