A numerical study on a temporal mixing layer under transcritical conditions

2013 ◽  
Vol 85 ◽  
pp. 93-104 ◽  
Author(s):  
Hiroumi Tani ◽  
Susumu Teramoto ◽  
Nobuhiro Yamanishi ◽  
Koji Okamoto
Keyword(s):  
Numerical Study ◽  
Mixing Layer ◽  
Temporal Mixing Layer

The promotion of ignition in a supersonic H2–air mixing layer by laser-induced excitation of O2 molecules: Numerical study

2009 ◽  
Vol 156 (8) ◽  
pp. 1641-1652 ◽  
Author(s):  
A.M. Starik ◽  
N.S. Titova ◽  
L.V. Bezgin ◽  
V.I. Kopchenov
Keyword(s):  
Numerical Study ◽  
Mixing Layer ◽  
Air Mixing

LES and Hybrid RANS/LES of a Fundamental Trailing Edge Slot

2014 ◽  
Author(s):  
Elizaveta Ivanova ◽  
Gregory M. Laskowski
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Numerical Study ◽  
Mixing Layer ◽  
Detached Eddy Simulation ◽  
Trailing Edge ◽  
Adiabatic Wall ◽  
Mean Velocity ◽  
Eddy Simulation ◽  
Delayed Detached Eddy Simulation

This paper presents the results of a numerical study on the predictive capabilities of Large Eddy Simulation (LES) and hybrid RANS/LES methods for heat transfer, mean velocity, and turbulence in a fundamental trailing edge slot. The geometry represents a landless slot (two-dimensional wall jet) with adjustable slot lip thickness. The reference experimental data taken from the publications of Kacker and Whitelaw [1] [2] [3] [4] contains the adiabatic wall effectiveness together with the velocity and the Reynolds-stress profiles for various blowing ratios and slot lip thicknesses. The simulations were conducted at three different lip thickness and several blowing ratio values. The comparison with the experimental data shows a general advantage of LES and hybrid RANS/LES methods against unsteady RANS. The predictive capability of the tested LES models (dynamic ksgs-equation [5] and WALE [6]) was comparable. The Improved Delayed Detached Eddy Simulation (IDDES) hybrid method [7] also shows satisfactory agreement with the experimental data. In addition to the described baseline investigations, the influence of the inlet turbulence boundary conditions and their implication for the initial mixing layer and heat transfer development were studied for both LES and IDDES.

Flow Stucture of Supersonic Underexpanded Jet With Microjets Injection

2013 ◽  
Vol 8 (1) ◽  
pp. 44-55
Author(s):  
Dmitriy Gubanov ◽  
Valeriy Zapryagaev ◽  
Nikolay Kiselev
Keyword(s):  
Flow Structure ◽  
Numerical Study ◽  
Mixing Layer ◽  
Supersonic Jet ◽  
Wave Structure ◽  
Streamwise Vortices ◽  
Jet Mixing ◽  
Underexpanded Jet ◽  
Supersonic Underexpanded Jet ◽  
The Impact

Experimental and numerical study of transversal microjets injection influence on the supersonic underexpanded jet flow structure has been performed. Data of measurements and calculation have acceptable agreement. Interaction of microjets with main supersonic jet sets to a decrease of an initial gasdynamic region. Microjets lead to a longitudinal streamwise vortices generation and a mushroom-like flow structures create on an external jet mixing layer. Dissipation of longitudinal streamwise vortices was observed at the second jet cell. Complex gasdynamic flow structure of the supersonic underexpanded jet interacting with supersonic microjets has been studied for the first time. This structure contains system of complex chock waves and expansion waves spreading from the position of the impact microjets/main jet localization place. Future of interaction process a chock-wave structure of main jet with additional shock waves has been studied

scholarly journals Computing multi-mode shock-induced compressible turbulent mixing at late times

2015 ◽  
Vol 779 ◽  
pp. 411-431 ◽  
Author(s):  
T. Oggian ◽  
D. Drikakis ◽  
D. L. Youngs ◽  
R. J. R. Williams
Keyword(s):  
Mach Number ◽  
Numerical Simulations ◽  
Compressible Flow ◽  
Turbulent Mixing ◽  
Numerical Study ◽  
Mixing Layer ◽  
Suitable Model ◽  
Late Time ◽  
Flow Equations ◽  
Multi Mode

Both experiments and numerical simulations pertinent to the study of self-similarity in shock-induced turbulent mixing often do not cover sufficiently long times for the mixing layer to become developed in a fully turbulent manner. When the Mach number of the flow is sufficiently low, numerical simulations based on the compressible flow equations tend to become less accurate due to inherent numerical cancellation errors. This paper concerns a numerical study of the late-time behaviour of a single-shocked Richtmyer–Meshkov instability (RMI) and the associated compressible turbulent mixing using a new technique that addresses the above limitation. The present approach exploits the fact that the RMI is a compressible flow during the early stages of the simulation and incompressible at late times. Therefore, depending on the compressibility of the flow field, the most suitable model, compressible or incompressible, can be employed. This motivates the development of a hybrid compressible–incompressible solver that removes the low-Mach-number limitations of the compressible solvers, thus allowing numerical simulations of late-time mixing. Simulations have been performed for a multi-mode perturbation at the interface between two fluids of densities corresponding to an Atwood number of 0.5, and results are presented for the development of the instability, mixing parameters and turbulent kinetic energy spectra. The results are discussed in comparison with previous compressible simulations, theory and experiments.

Effect of viscosity gradients on mean velocity profile in temporal mixing layer

2016 ◽  
Vol 17 (5) ◽  
pp. 491-517 ◽  
Author(s):  
N. Taguelmimt ◽  
L. Danaila ◽  
A. Hadjadj
Keyword(s):  
Velocity Profile ◽  
Mixing Layer ◽  
Mean Velocity ◽  
Temporal Mixing Layer
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