Numerical simulations of gaseous cellular detonation interaction with bluff-body obstacles

2020 ◽  
Author(s):  
G. Bakalis ◽  
X. Q. Yuan ◽  
H. D. Ng
Keyword(s):  
Numerical Simulations ◽  
Bluff Body ◽  
Cellular Detonation

scholarly journals Experimental and CFD analysis of MHD flow around smooth sphere and sphere with dimples in subcritical and critical regimes

2020 ◽  
pp. 197-197
Author(s):  
Jasmina Bogdanovic-Jovanovic ◽  
Zivojin Stamenkovic
Keyword(s):  
Magnetic Field ◽  
Numerical Simulations ◽  
Bluff Body ◽  
Slight Modification ◽  
Mhd Flow ◽  
Stationary Flow ◽  
Working Fluid ◽  
Detached Eddy Simulation ◽  
Reynolds Stresses ◽  
Smooth Sphere

An overview of previous researches related to the problem of flow around a bluff-body, using experimental and numerical methods, is presented in the paper. Experimental investigation was performed by a Laser Doppler Anemometer (LDA), measuring velocity components of the water flow around a smooth sphere and a sphere with dimples in square channels. Measurement results in subcritical velocity flow field, velocity fluctuation components, lift, drag and pressure coefficients, and 2D Reynolds stress at quasi-stationary flow are conducted using 1D LDA probe. The obtained experimental results are compared with numerical simulations, which are performed using the ANSYS-CFX software. For the numerical simulations of quasi-steady-state flow, k-? turbulent model was used, while for numerical simulation of unsteady fluid flow and for the comparison of results related to the eddy structures, vortex shedding and Reynolds stresses, Detached Eddy Simulation were used. Since the obtained results of experimental and numerical investigation of flow around smooth sphere and sphere with dimples showed good agreement, the considered flow problem was expanded by introducing the influence of a transverse magnetic field with a slight modification of the electrical conductivity of the working fluid. The other physical properties of the fluid remained the same, which also corresponds to realistically possible physical conditions. Numerical simulations were performed for three different values of Hartmann number and very small values of Reynolds magnetic number (inductionless approximation). Comparisons and analyzes of the results were made for the cases containing a magnetic field and those with an absence of a magnetic field.

scholarly journals Numerical simulations of cellular detonation diffraction in a stable gaseous mixture

2016 ◽  
Vol 5 (3) ◽  
pp. 177-183 ◽  
Author(s):  
Jian Li ◽  
Jianguo Ning ◽  
Charles B. Kiyanda ◽  
Hoi Dick Ng
Keyword(s):  
Numerical Simulations ◽  
Gaseous Mixture ◽  
Cellular Detonation

A Comparative Study Between DNS, LES and PIV for a Marine Riser With Fairings

2015 ◽  
Author(s):  
Håkon Strandenes ◽  
José Patricio Gallardo Canabes ◽  
Jan Visscher ◽  
Bjørnar Pettersen ◽  
Helge I. Andersson ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Bluff Body ◽  
Mean Flow ◽  
Surface Integral ◽  
Circulating Water ◽  
Flow Parameters ◽  
Image Velocimetry ◽  
Drag And Lift ◽  
Recirculation Length ◽  
Bluff Body Wake

This paper present results from numerical simulations and laboratory experiments investigating the flow around a riser with fairings at Reynolds number of 5000. We present fully resolved direct numerical simulations (DNS), large eddy simulations (LES) and compare the results with flowfields obtained from particle image velocimetry (PIV) experiments in a circulating water tunnel. The DNS and LES results do agree very well on surface integral quantities such as drag and lift force, but there are discrepancies in first order statistical flow parameters such as recirculation length. This indicate that a comparison of force coefficients is not sufficient to validate this type of bluff body wake flows. Comparing the simulation data with the experimental PIV data, also reveals significant discrepancies in the mean flow field, although the Strouhal number agrees between DNS and PIV results.

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