Mechanism of supersonic mixing enhancement by a wall-mounted three-dimensional cavity

2021 ◽  
Vol 188 ◽  
pp. 491-504
Author(s):  
Masayuki Anyoji ◽  
Fujio Akagi ◽  
Yu Matsuda ◽  
Yasuhiro Egami ◽  
Taro Handa
Keyword(s):  
Three Dimensional ◽  
Mixing Enhancement ◽  
Supersonic Mixing

Supersonic mixing enhanced by cavity-induced three-dimensional oscillatory flow

2014 ◽  
Vol 55 (4) ◽  
Author(s):  
Taro Handa ◽  
Aoi Nakano ◽  
Kazuya Tanigawa ◽  
Jun Fujita
Keyword(s):  
Oscillatory Flow ◽  
Three Dimensional ◽  
Supersonic Mixing

602 Supersonic Mixing Enhancement Using Interaction between Jet and Flexible Rubber Sheets

2007 ◽  
Vol 2007.56 (0) ◽  
pp. 273-274
Author(s):  
Shohei YAMASHITA ◽  
Yohei YOSHIDA ◽  
Kazuhiko YOKOTA ◽  
Motoyuki ITOH ◽  
Shinji TAMANO
Keyword(s):  
Mixing Enhancement ◽  
Supersonic Mixing

scholarly journals A LES Study on Passive Mixing in Supersonic Shear Layer Flows Considering Effects of Baffle Configuration

2014 ◽  
Vol 6 ◽  
pp. 836146 ◽  
Author(s):  
Ren Zhao-Xin ◽  
Wang Bing
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
Large Scale ◽  
Mixing Layer ◽  
Total Pressure Loss ◽  
Mixing Efficiency ◽  
Mixing Enhancement ◽  
Supersonic Mixing ◽  
Passive Mixing ◽  
Supersonic Mixing Layer

Under the background of dual combustor ramjet (DCR), a numerical investigation of supersonic mixing layer was launched, focused on the mixing enhancement method of applying baffles with different geometric configurations. Large eddy simulation with high order schemes, containing a fifth-order hybrid WENO compact scheme for the convective flux and sixth-order compact one for the viscous flux, was utilized to numerically study the development of the supersonic mixing layer. The supersonic cavity flow was simulated and the cavity configuration could influence the mixing characteristics, since the impingement process of large scale structures formed inside the cavity could raise the vorticity and promote the mixing. The effect of baffle's configurations on the mixing process was analyzed by comparing the flow properties, mixing efficiency, and total pressure loss. The baffle could induce large scale vortexes, promote the mixing layer to lose its stability easily, and then lead to the mixing efficiency enhancement. However, the baffle could increase the total pressure loss. The present investigation could provide guidance for applying new passive mixing enhancement methods for the supersonic mixing.

Numerical Simulation of Supersonic Mixing Enhanced by a Three-Dimensional Cavity Flow

2015 ◽  
Author(s):  
Takayuki Oka ◽  
Fujio Akagi ◽  
Taro Handa ◽  
Youichi Ando ◽  
Sumio Yamaguchi
Keyword(s):  
Three Dimensional ◽  
Cavity Flow ◽  
Secondary Flows ◽  
Navier Stokes ◽  
Computational Results ◽  
Primary Flow ◽  
Transverse Jet ◽  
Supersonic Mixing ◽  
Dimensional Shape ◽  
Three Dimensional Shape

The three-dimensional mixing field induced by a novel wall-mounted cavity having a three-dimensional shape, which has been proposed in the other literature, is investigated in detail by solving the Reynolds-averaged Navier-Stokes (RANS) equations computationally. The results indicate that secondary flows are produced from the cavity and that the secondary flows act on the transverse jet such a way that it penetrates highly into the primary flow; i.e., the computational results demonstrates that the proposed cavity functions effectively as a device for enhancing supersonic mixing.

scholarly journals Controlling Mixing Inside a Droplet by Time Dependent Rigid-Body Rotation

2008 ◽  
Author(s):  
Rodolphe Chabreyrie ◽  
Dmitri Vainchtein ◽  
Cristel Chandre ◽  
Pushpendra Singh ◽  
Nadine Aubry
Keyword(s):  
Rigid Body ◽  
Liquid Droplet ◽  
Three Dimensional ◽  
Time Dependent ◽  
Mixing Enhancement ◽  
Body Rotation ◽  
Rigid Body Rotation ◽  
Digital Microfluidic ◽  
And Control ◽  
Time Periodic

The use of microscopic discrete fluid volumes (i.e., droplets) as microreactors for digital microfluidic applications often requires mixing enhancement and control within droplets. In this work, we consider a translating spherical liquid droplet to which we impose a time periodic rigid-body rotation which we model using the superposition of a Hill vortex and an unsteady rigid body rotation. This perturbation in the form of a rotation not only creates a three-dimensional chaotic mixing region, which operates through the stretching and folding of material lines, but also offers the possibility of controlling both the size and the location of the mixing. Such a control is achieved by judiciously adjusting the three parameters that characterize the rotation, i.e., the rotation amplitude, frequency and orientation of the rotation. As the size of the mixing region is increased, complete mixing within the drop is obtained.

Elliptic jets. Part 3. Dynamics of preferred mode coherent structure

1993 ◽  
Vol 248 ◽  
pp. 315-361 ◽  
Author(s):  
Hyder S. Husain ◽  
Fazle Hussain
Keyword(s):  
Coherent Structure ◽  
Near Field ◽  
Three Dimensional ◽  
Mixing Enhancement ◽  
Hot Wire ◽  
Vortical Structures ◽  
Mass Entrainment ◽  
Time Average ◽  
And Control ◽  
Made In

The dynamics of the preferred mode structure in the near field of an elliptic jet have been investigated using hot-wire measurements. A 2:1 aspect ratio jet with an initially turbulent boundary layer and a constant momentum thickness all around the nozzle exit perimeter was used for this study. Measurements were made in air at a Reynolds number ReDe (≡ UeDe/v) = 3.5 × 104. Controlled longitudinal excitation at the preferred mode frequency (StDe ≡ fDe/Ue = 0.4) induced periodic formation of structures, allowing phase-locked measurements with a local trigger hot wire. The dynamics of the organized structure are examined from educed fields of coherent vorticity and incoherent turbulence in the major and minor symmetry planes at five successive phases of evolution, and are also compared with corresponding data for a circular jet. Unlike in a circular jet, azimuthally fixed streamwise vortices (ribs) form without the aid of azimuthal forcing. The three-dimensional deformation of elliptic vortical structures and the rib formation mechanism have also been studied through direct numerical simulation. Differential self-induced motions due to non-uniform azimuthal curvature and the azimuthally fixed ribs produce greater mass entrainment in the elliptic jet than in a circular jet. The turbulence production mechanism, entrainment and mixing enhancement, and time-average measures and their modification by excitation are also discussed in terms of coherent structure dynamics and the rib-roll interaction. Various phase-dependent and time-average turbulence measures documented in this paper should serve as target data for validation of numerical simulations and turbulence modelling, and for design and control purposes in technological applications. Further details are given by Husain (1984).

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