scholarly journals Richtmyer-Meshkov Instability Induced Mixing Enhancement in the Scramjet Combustor with a Central Strut

2014 ◽  
Vol 6 ◽  
pp. 614189 ◽  
Author(s):  
Qingchun Yang ◽  
Juntao Chang ◽  
Wen Bao
Keyword(s):  
High Temperature ◽  
Numerical Method ◽  
Chemical Reactions ◽  
Numerical Study ◽  
Numerical Results ◽  
Mixing Efficiency ◽  
Mixing Enhancement ◽  
Scramjet Combustor ◽  
Ordinary Temperature ◽  
Scramjet Engine

Experimental and numerical study of Richtmyer-Meshkov instability (RMI) induced mixing enhancement has been conducted in a liquid-fueled scramjet engine with a central strut. To generate the RMI in the scramjet engine, transverse high temperature jets are employed downstream the strut injector. Compared to the transverse ordinary temperature jet, the jet penetration into the supersonic airstream of high temperature jet increases by 60%. The numerical results indicate that the RMI phenomenon markedly enhances the mixing efficiency (up to 43%), which is necessary to initiate the chemical reactions. Ground experiments were carried out in the combustor, which verify the numerical method from the perspective of wall pressures of the combustor. In particular, the experiment results indicate that the RMI can benefit flame-holding due to the mixing enhancement.

scholarly journals Experimental and Numerical Study on Pressure Distribution of 90° Elbow for Flow Measurement

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Beibei Feng ◽  
Shiming Wang ◽  
Shengqiang Li ◽  
Xingtuan Yang ◽  
Shengyao Jiang
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Pressure Distribution ◽  
Flow Measurement ◽  
Static Pressure ◽  
Numerical Study ◽  
Numerical Approach ◽  
Test System ◽  
Numerical Results ◽  
Helium Gas

Numerical simulation is performed to investigate the pressure distribution of helium gas under high pressure and high temperature for 10 MW High Temperature Gas-Cooled Reactor (HTGR-10). Experimental studies are first conducted on a self-built test system to investigate the static pressure distribution of a 90° elbow and validate the credibility of the computational approach. The 90° elbow is designed and manufactured geometrically the same as HTGR-10. Based on the experimental data, comparison of static pressure of inner wall and outer wall of 90° elbow with numerical results is carried out to verify the numerical approach. With high agreement between experimental results and numerical results of water flowing through 90° elbow, flow characteristics of helium gas under high pressure and high temperature are investigated on the confirmed numerical approach for flow measurement. And wall pressure distribution of eight cross sections of 90° elbow is given in detail to represent the entire region of the elbow.

A numerical study on the mixing of air and hydrogen in a scramjet combustor

2005 ◽  
Vol 109 (1097) ◽  
pp. 325-335
Author(s):  
M. Ali ◽  
T. Fujiwara
Keyword(s):  
Stokes Equations ◽  
Numerical Study ◽  
Side Wall ◽  
Recirculation Region ◽  
Mixing Efficiency ◽  
Main Stream ◽  
Two Dimensional ◽  
Injection Angle ◽  
Scramjet Combustor ◽  
Flow Field Characteristics

Abstract A numerical study on mixing of air and hydrogen is performed by solving two-dimensional full Navier-Stokes equations. The main stream is air of Mach 5 entering through the configured inlet of the combustor and gaseous hydrogen is injected from the configured jet on the side wall. Supersonic mixing and diffusion mechanisms of a transverse hydrogen jet in two-dimensional finite air streams have been analyzed and discussed. The computed results are compared with the experimental data and show good agreement. For an otherwise fixed combustor geometry, the air inlet width and injection angle are varied to study the physics of mixing and flow field characteristics. On the effect of inlet width variation, two competing phenomena have been observed: (i) upstream of injector the strength of recirculation is higher for wider inlet and consequently the mixing increases, and (ii) downstream, the diffusion of hydrogen decreases with the increase of inlet width and eventually mixing decreases. As a result, in far downstream the mixing efficiency increases up to certain inlet width and then decreases for further increment of inlet width. For the variation of injection angle results show that upstream of injector the mixing is dominated by recirculation and downstream the mixing is dominated by mass concentration of hydrogen. Upstream recirculation is dominant for injecting angle 60° and 90°. Incorporating the various effects, perpendicular injection shows the maximum mixing efficiency and its large upstream recirculation region has a good flame holding capability.

Mixing Enhancement With Rotating Ramps in a Scramjet Engine

2016 ◽  
Author(s):  
Liang Jin ◽  
Wei Huang ◽  
Zhen Liu ◽  
Jun Liu
Keyword(s):  
Fuel Injection ◽  
Mixing Efficiency ◽  
Mixing Enhancement ◽  
Hydrogen Fuel ◽  
Commercial Software ◽  
Speed Increase ◽  
Injection Channel ◽  
Ramjet Engine ◽  
Scramjet Engine

A concept of mixing enhancement forced by rotating ramps has been presented, which based on the design of stationary ramps and Rim-Rotor Rotary Ramjet Engine. The commercial software Fluent has been conducted to study the nonreacting flowfields in a transverse hydrogen fuel injection channel. The results indicate a slowly increased mixing efficiency when the ramps speed increase. As the ramps rotate at a speed of 6000rpm, the mixing efficency is almost the same as the stationary ramps case. As the ramps rotate at a speed of 54295rpm, a 10%∼20% higher mixing efficiency is obtained.

Numerical Study of Mixing Enhancement by Shock Waves in Model Scramjet Engine

AIAA Journal ◽  
2003 ◽  
Vol 41 (6) ◽  
pp. 1074-1080 ◽  
Author(s):  
Ji-Ho Kim ◽  
Youngbin Yoon ◽  
In-Seuck Jeung ◽  
Hwanil Huh ◽  
Jeong-Yeol Choi
Keyword(s):  
Shock Waves ◽  
Numerical Study ◽  
Mixing Enhancement ◽  
Scramjet Engine

Effects of pylon geometry on mixing enhancement in a scramjet pylon-cavity flameholder

2020 ◽  
Vol 124 (1278) ◽  
pp. 1262-1280
Author(s):  
A. Oamjee ◽  
R. Sadanandan
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
Supersonic Combustion ◽  
Total Pressure Loss ◽  
Absolute Pressure ◽  
Mixing Efficiency ◽  
Mixing Enhancement ◽  
Scramjet Combustor ◽  
Fuel Jet ◽  
Jet Penetration

ABSTRACTNumerical investigation of the effect of pylon geometry within a pylon-cavity aided Supersonic Combustion Ramjet (SCRAMJET) combustor on mixing enhancement, flame-holding capability, fuel jet penetration and total pressure loss are conducted in the current study. RANS equations for compressed real gas are solved by coupled, implicit, second-order upwind solver. A two-equation SST model is used for turbulence modelling. Validation of the computational model is performed with the help of experimental data collected using surface pressure taps, Schlieren flow visualisation and particle image velocimetry (PIV). The study uses four distinct pylon geometry cases, which include the baseline geometry. Sonic injection of hydrogen fuel through a 1mm diameter hole at 2mm downstream of the pylon rear face along the axis of the test section floor is performed for every case. A crossflow of Mach number 2.2 at four bar absolute pressure and standard atmospheric temperature is maintained. A comparative study of mixing efficiency, total pressure loss, fuel jet penetration and fuel plume area fraction for the different cases evaluate the mixing performance. The simulations show that the Pylon 2 case gives a significant improvement in the performance parameters compared to the other geometries. It is observed that mixing efficiency and fuel jet penetration capability of the system are highly dependent on the streamwise vortex within the flameholder.

Numerical Study of Scramjet Combustor with Tandem Dual Cavity for Nonreactive Jets

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Ajin Branesh ◽  
Jeevanjot Kaur ◽  
Akashdeep Singh
Keyword(s):  
Numerical Study ◽  
Combustion Efficiency ◽  
Reacting Flows ◽  
Scramjet Combustor ◽  
Different Types ◽  
Mixing Rates ◽  
Varying Length ◽  
Scramjet Engine ◽  
Compressibility Effects ◽  
Convective Mach Number

In the past decades flame out is a major phenomenon that paves way for high fuel consumption in scramjet combustion. For enhancing mixing and flame holding characteristics, different types of cavities are introduced in a scramjet combustion chamber which can hold air for a bit and acts like an atomizer. For increasing combustion efficiency and burnout ratios recirculation is maintained by using cavity and ramp angle techniques. In this paper numerical analysis has been carried out for two dimensional non-reacting flows in the combustor of scramjet engine with tandem dual cavity that creates high turbulent kinetic energy for ensuring combustion instability. This work is an enlightened approach for predicting the flow phenomenon that induces re-circulations after implementing various tandem dual cavities with varying length to diameter ratio and ramp angle. These in turn overcome low mixing rates due to compressibility effects at high convective Mach number.

scholarly journals Mixing efficiency of hydrogen jet through multi lobe-injectors at scramjet engine: A numerical study

2021 ◽  
pp. 107293
Author(s):  
Peixi Guo ◽  
Xiaowei Li ◽  
Nidal H. Abu-Hamdeh ◽  
Rashad A.R. Bantan
Keyword(s):  
Numerical Study ◽  
Mixing Efficiency ◽  
Scramjet Engine

Using Ansys for Design and Numerical Study of a Specific Fixed Wing UAV

2018 ◽  
Vol 55 (4) ◽  
pp. 652-657 ◽  
Author(s):  
Gabriel Murariu ◽  
Razvan Adrian Mahu ◽  
Adrian Gabriel Murariu ◽  
Mihai Daniel Dragu ◽  
Lucian P. Georgescu ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Unmanned Aerial Vehicle ◽  
Numerical Study ◽  
Flight Time ◽  
Cluster System ◽  
Numerical Results ◽  
Operational Performance ◽  
Gliding Flight ◽  
Aerial Vehicle ◽  
Constant Altitude

This article presents the design of a specific unmanned aerial vehicle UAV prototype own building. Our UAV is a flying wing type and is able to take off with a little boost. This system happily combines some major advantages taken from planes namely the ability to fly horizontal, at a constant altitude and of course, the great advantage of a long flight-time. The aerodynamic models presented in this paper are optimized to improve the operational performance of this aerial vehicle, especially in terms of stability and the possibility of a long gliding flight-time. Both aspects are very important for the increasing of the goals� efficiency and for the getting work jobs. The presented simulations were obtained using ANSYS 13 installed on our university� cluster system. In a next step the numerical results will be compared with those during experimental flights. This paper presents the main results obtained from numerical simulations and the obtained magnitudes of the main flight coefficients.

Numerical study of the flow of a mixture of reacting gases in an inhomogeneous catalyst layer

2003 ◽  
Vol 3 ◽  
pp. 246-254
Author(s):  
C.I. Mikhaylenko ◽  
S.F. Urmancheev
Keyword(s):  
Velocity Field ◽  
Chemical Reactions ◽  
Porous Layer ◽  
Computational Experiment ◽  
Numerical Study ◽  
Fluid Velocity ◽  
Catalyst Layer ◽  
Granular Catalyst ◽  
Fluid Velocity Field

The behavior of a liquid flowing through a fixed bulk porous layer of a granular catalyst is considered. The effects of the nonuniformity of the fluid velocity field, which arise when the surface of the layer is curved, and the effect of the resulting inhomogeneity on the speed and nature of the course of chemical reactions are investigated by the methods of a computational experiment.

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