Computational Analysis of Mixing in Scramjet Combustor using Cross Flow Injection Technique

Author(s):  
D. Hasen ◽  
R. Karthikeyan ◽  
M. Sundararaj ◽  
K. M. Parammasivam

The prime issue in supersonic combustion is proper mixing within short duration of time. Computational study has been performed to analyse the mixing of air and fuel using cross flow injection technique. Cross flow injection is performed by placing the fuel injectors on the walls of the scramjet engine which is perpendicular to the flow. To enhance the mixing of fuel and air, cavities were introduced. The flow recirculation inside the cavity will enhance the mixing and combustion. The fuel injectors were placed just upstream of the cavity. Analyses were done by changing the injection angles. The air is allowed to enter at different Mach numbers and the changes were analysed using ANSYS software. The roles of cavity cross flow injection, pressure, temperature, velocity and Mach number variation were examined in this study and the obtained results were compared between various configurations.

2018 ◽  
Vol 68 (2) ◽  
pp. 121 ◽  
Author(s):  
Malsur Dharavath ◽  
P. Manna ◽  
Debasis Chakraborty

The knowledge of transverse sonic injection flow field is very important for the design of scramjet combustor. Three dimensional Reynolds-Averaged Navier Stokes equations alongwith turbulence models are solved to find the effect of transverse sonic slot injection into a supersonic flow. Grid sensitivity of the results is studied for various structured grids. Simulations with different turbulence models (i.e., k-ε, k-ω, SST-kω, and RNG-kε) reveals that RNG-kε turbulence model better predicts the flow features. Computational fluid dynamics predicted wall pressure distribution for various injection pressures matches well with experimental data. The extent of upstream separated region increases with the increase of the injection pressure. The increase of slot width makes the interaction between transverse jet and free stream more intense and causes more spreading and penetration of injectant in the downstream region.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jeyakumar Suppandipillai ◽  
Jayaraman Kandasamy ◽  
R. Sivakumar ◽  
Mehmet Karaca ◽  
Karthik K.

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.


1992 ◽  
Vol 261 (1-2) ◽  
pp. 287-294 ◽  
Author(s):  
R.T. Edwards ◽  
I.D. McKelvie ◽  
P.C. Ferrett ◽  
B.T. Hart ◽  
J.B. Bapat ◽  
...  

2021 ◽  
Author(s):  
Sajal Katare ◽  
Nagendra P. Yadav

Abstract This paper focuses the computational study of non-premixed combustion in a scramjet combustor. The wedge shaped strut injector was used in the combustion process. In order to investigate the flame holding mechanism of the wedge shaped strut in supersonic flow, the two-dimensional coupled implicit RANS equations, the standard k-ε turbulence model and the finite-rate/eddy-dissipation reaction model are introduced to simulate the flow field of the hydrogen fueled scramjet combustor with a strut flame holder under different conditions. The static pressure of the case under the engine ignition condition is much higher than that of the case under the cold flow condition. The reflection of shock waves improves the mixing of hydrogen with the stream of inlet air and thus increases combustion efficiency. The mass flow rate of air is optimized for the best performance of engine.


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