Computational Analysis of Supersonic Combustion Using Wedge-Shaped Strut Injector with Turbulent Non-Premixed Combustion Model (original) (raw)
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T RANSACTION ON C ONTROL AND M ECHANICAL S YSTEMS , V OL . 1, N O . 2,, 2012
This paper presents the supersonic combustion of hydrogen using strut injector along with two-dimensional turbulent non-premixed combustion model. The process of numerical analysis based on the implicit formulation method which is pressure based solver along with absolute velocity formulation and steady turbulent Navier-Stokes equations. The present model is based on the standard k-epsilon (two equations) with standard wall functions which is P1 radiation model. In this process, a probability density function (PDF) approach is created and this method needs solution to a high dimensional PDF transport equation. As the combustion of hydrogen fuel is injected from the strut, it is successfully used to model the turbulent reacting flow field. It is observed from the present work that, the maximum temperature occurred in the recirculation areas which are produced due to shock wave-expansion, wave-jet interaction and the fuel jet losses concentration and after passing successively through such areas, temperature decreased slightly along the axis.
In this paper the supersonic combustion of hydrogen using strut injector along with two-dimensional turbulent nonpremixed combustion model. The present work is based on the standard kε which has been used for modeling the turbulence and single step finite rate chemistry. In this process, a PDF (Probability Density Function) approach is created and this method needs solution to a high dimensional PDF transport equation. After designing the model in GAMBIT, it is exported to FLEUNT software for analysis of combustion process with air inlet at Mach number 2 and hydrogen as the fuel with inlet Mach number 1. As the combustion of hydrogen fuel is injected from the strut injector, it is successfully used to model the turbulent reacting flow field. It is observed from the present work that, the maximum temperature occurred in the recirculation areas which is produced due to shock waveexpansion and the fuel jet losses concentration and after passing successively through such areas, temperature decreased slightly along the axis. From the maximum mass fraction of OH, it is observed that there is very little amount of OH around 0.00233 were found out after combustion. By providing strut injector, expansion wave is created which cause the proper mixing between the fuels and air which results in complete combustion.
TRANSACTION ON CONTROL AND MECHANICAL SYSTEMS
The supersonic combustion of hydrogen using diamond-shaped strut injector along with two-dimensional non-premixed combustion model is presented in this paper. The present work stresses on the k-ω which has been used for modelling the turbulence and single step finite rate chemistry. In this process, a PDF approach is created and this method needs solution to a high dimensional PDF transport equation. As the combustion of hydrogen fuel is injected from the diamond-shaped strut injector, it is successfully used to model the turbulent reacting flow field. From the present work it has been observed that, the maximum temperature occurred in the recirculation areas which is produced due to shockwave-expansion and the fuel jet losses concentration and after passing successively through such areas, temperature decreased slightly along the axis. From the maximum mass fraction of OH, it is seen that there is very little amount of OH around 0.0035 were found out after combustion. By providing strut injector, expansion wave is created which caused the proper mixing between the fuels and air which resulted in complete combustion.
International Journal of Advanced Trends in Computer Science and Engineering
In this paper the CFD analysis of supersonic combustion of hydrogen using wedge shaped strut having circular inlet with standard k-º non premixed turbulence model is discussed. In doing this a PDF(Probability Density Function) approach is created and this method needs solution to a high definition The present work is based on designing the model using ANSYS 14 software and then the FLUENT analysis is also done for analysis of combustion process with air inlet at Mach number 3 and hydrogen inlet at Mach number 1.5. The obtained results show that the numerical method used in this paper is suitable to simulate the flow field of the scramjet combustor. The eddy generated in the strut acts as a flame holder in the combustor, and it can prolong the residence time of the mixture in the supersonic flow.
International Journal of Advanced Trends in Computer Science and Engineering
This work presents the supersonic combustion of hydrogen using ramp injector along with two-dimensional turbulent non-premixed combustion model. The work is based on the standard k-ω which has been used for modeling the turbulence and single step finite rate chemistry. As the combustion of hydrogen fuel is injected from the strut injector, it is successfully used to model the turbulent reacting flow field. It is observed from the present work that, the maximum temperature occurred in the recirculation areas which is produced due to shock wave-expansion and the fuel jet losses concentration and after passing successively through such areas, temperature decreased slightly along the axis. From the maximum mass fraction of OH, it is observed that there is very little amount of OH around 0.019 were found out after combustion. By providing strut injector, expansion wave is created which cause the proper mixing between the fuels and air which results in complete combustion.
International Journal of Advanced Trends in Computer Science and Engineering
This work presents the supersonic combustion of hydrogen using ramp injector along with two-dimensional turbulent non-premixed combustion model. The work is based on the standard k-ω which has been used for modeling the turbulence and single step finite rate chemistry. As the combustion of hydrogen fuel is injected from the strut injector, it is successfully used to model the turbulent reacting flow field. It is observed from the present work that, the maximum temperature occurred in the recirculation areas which is produced due to shock wave-expansion and the fuel jet losses concentration and after passing successively through such areas, temperature decreased slightly along the axis. From the maximum mass fraction of OH, it is observed that there is very little amount of OH around 0.019 were found out after combustion. By providing strut injector, expansion wave is created which cause the proper mixing between the fuels and air which results in complete combustion
A computational study of supersonic combustion in strut injector and hypermixer flow fields
Proceedings of the Combustion Institute
Achieving sufficiently high combustion efficiency and stability in supersonic combustion is extremely challenging and highly dependent on the fuel-injection and mixing strategies adopted. A viable approach to this is the strut injector, which by inducing flow recirculation, facilitates flame stabilization in the strut-wake. In this investigation we examine in detail the flow, mixing, self-ignition and flame stabilization mechanisms of conventional and alternating-wedge injection struts. In order to analyze these, we consider NAL’s supersonic combustor, equipped with two conventional two-stage injection struts, and an alternating-wedge injection strut, in conjunction with ONERA’s vitiation air heater. Experimental results, including spontaneous flame images, wall-pressure and Planar Laser Induced Fluorescence (PLIF) images of hydroxyl (OH) are here combined with computational results based on finite-rate chemistry Large Eddy Simulation (LES) with skeletal hydrogen-air reaction mechan...
Numerical Analysis of Supersonic Combustion by Strut Flat Duct Length with S-A Turbulence Model
IACSIT International Journal of Engineering and Technology, Vol.3, No.2,, 2011
n this numerical study, supersonic combustion of hydrogen has been presented with strut flat duct length. The combustor has a single fuel injection parallel to the main flow from the base. Finite rate chemistry model with S-A Model have been used for modeling of supersonic combustion. In this paper strut at 60 with flat duct length analyzed for without hydrogen injection, with hydrogen injection and hydrogen injection with combustion. The investigation of the shock system produced by a strut injector with subsequent mixing, ignition and flame stabilization showed that the characteristics of the ignition process is considerably different from the shock induced ignition which has been postulated in the past. The ignition is achieved through the irreversible total pressure loss in the wake of Strut due to flat duct length. Flat duct lengths allow the ignition delay to occur before the pressure and temperature is decreased by the expansion. The presence of a boundary layer in the chamber changes the shock system and the ignition conditions in the chamber considerably
Computational analysis of supersonic combustion with swept ramp injection using K- turbulence model
In this Paper numerical study with swept ramp injection in supersonic combustion of hydrogen has been presented. Coupled implicit scheme with finite rate chemistry model and K-ε Turbulence model have been used for modeling of supersonic combustion. The main issue in supersonic combustion is proper mixing within short burst of time. Because of the step on the top wall of the combustor, there exists an expansion fan generated just on the top wall at the entrance of the combustor, which is interacts with the oblique shock wave formed upstream of the combustor due to the shear layer deflecting into the core flow. The static pressures along the walls are normalized by the static pressure of the core flow. The present result is very promising and demonstrates that flamelet approach seems to be feasible to high-speed flows. The stagnation temperature in the combustion reaches up to 2830 k. Fluctuation in pressure and Mach number was due to shock train.
2018
A major problem in supersonic combustion is the short residence time of the fluid inside the combustor due to high flow velocities. Thus techniques for mixing enhancement have to be used to achieve a fast and efficient fuel-air mixing. In the present project work, different types of strut fuel injectors are investigated numerically, mainly strut with circular injector, strut with planer injector and strut with alternating wedge injector. The combustor and strut dimensions are same as DLR Scramjet model. It consists of a divergent channel with a flame – holding, wedge shaped structure in the middle of the flow field from the base of which hydrogen is injected. Study of mixing and combustion enhancement has been performed for a Mach 2 and Fuel (hydrogen) is injected at supersonic speed of Mach 1. The simulations have been performed using FLUENT. Standard k-e model has been used for modeling turbulence and single step finite rate chemistry has been used for modeling the H2-Air kinetics...