scholarly journals NUMERICAL CALCULATION OF FLOWS BY A RUBBLE MOUND GROIN BY A COMBINED MODEL OF A POROUS FLOW MODEL WITH A NONDARCIAN RESISTANCE LAW AND A 3-DIMENSIONAL LES MODEL

2008 ◽  
Vol 52 ◽  
pp. 1045-1050
Author(s):  
Ryosuke AKAHORI ◽  
Kohji MICHIOKU
Keyword(s):  
Numerical Calculation ◽  
Flow Model ◽  
Combined Model ◽  
Porous Flow ◽  
3 Dimensional ◽  
Rubble Mound ◽  
Les Model

Larger-Eddy Simulation of Velocity Fluctuation in a Mixing T-Junction

2012 ◽  
Vol 152-154 ◽  
pp. 1313-1318
Author(s):  
Tao Lu ◽  
Su Mei Liu ◽  
Ping Wang ◽  
Wei Yyu Zhu
Keyword(s):  
Experimental Data ◽  
Velocity Fluctuation ◽  
Flow Model ◽  
Numerical Results ◽  
Mean Square ◽  
Main Duct ◽  
Velocity Fluctuations ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Les Model

Velocity fluctuations in a mixing T-junction were simulated in FLUENT using large-eddy simulation (LES) turbulent flow model with sub-grid scale (SGS) Smagorinsky–Lilly (SL) model. The normalized mean and root mean square velocities are used to describe the time-averaged velocities and the velocities fluctuation intensities. Comparison of the numerical results with experimental data shows that the LES model is valid for predicting the flow of mixing in a T-junction junction. The numerical results reveal the velocity distributions and fluctuations are basically symmetrical and the fluctuation at the upstream of the downstream of the main duct is stronger than that at the downstream of the downstream of the main duct.

Intrapleural fluid movements described by a porous flow model

1992 ◽  
Vol 73 (6) ◽  
pp. 2511-2516 ◽  
Author(s):  
G. Miserocchi ◽  
D. Venturoli ◽  
D. Negrini ◽  
M. C. Gilardi ◽  
R. Bellina
Keyword(s):  
Porous Medium ◽  
Gamma Camera ◽  
Flow Model ◽  
Pleural Space ◽  
Interstitial Tissue ◽  
Hydraulic Pressure ◽  
Pressure Gradients ◽  
Hydraulic Radius ◽  
Porous Flow ◽  
Anesthetized Dogs

We injected technetium-labeled albumin (at a concentration similar to that of the pleural fluid) in the costal region of anesthetized dogs (n = 13) either breathing spontaneously or apneic. The decay rate of labeled activity at the injection site was studied with a gamma camera placed either in the anteroposterior (AP) or laterolateral (LL) projection. In breathing animals (respiratory frequency approximately 10 cycles/min), 10 min after the injection the activity decreased by approximately 50% on AP and approximately 20% on LL imaging; in apneic animals the corresponding decrease in activity was reduced to approximately 15 and approximately 3%, respectively. We considered label translocation from AP and LL imaging as a result of bulk flows of liquid along the costomediastinal and gravity-dependent direction, respectively. We related intrapleural flows to the hydraulic pressure gradients existing along these two directions and to the geometry of the pleural space. The pleural space was considered as a porous medium partially occupied by the mesh of microvilli protruding from mesothelial cells. Solution of the Kozeny-Carman equation for the observed flow velocities and pressure gradients yielded a mean hydraulic radius of the pathways followed by the liquid ranging from 2 to 4 microns. The hydraulic resistivity of the pleural space was estimated at approximately 8.5 x 10(5) dyn.s.cm-4, five orders of magnitude lower than that of interstitial tissue.

scholarly journals Simulations of Aeroelasticity in an Annular Cascade Using a Parallel 3-Dimensional Navier-Stokes Solver

2002 ◽  
Author(s):  
Ivan McBean ◽  
Feng Liu ◽  
Kerry Hourigan ◽  
Mark Thompson
Keyword(s):  
Unsteady Flow ◽  
Flow Model ◽  
Standard Test ◽  
Navier Stokes ◽  
Test Case ◽  
Turbine Cascade ◽  
3 Dimensional ◽  
Flow Through ◽  
The Stability ◽  
Annular Cascade

A parallel multi-block Navier-Stokes solver with the k-ω turbulence model is developed to simulate the 3-dimensional unsteady flow through an annular turbine cascade. Results at mid-span are compared with the experimental results of Standard Test Case 4. Comparisons are made between 3-dimensional and 2-dimensional, and inviscid and viscous simulations. The inclusion of a viscous flow model does not greatly affect the stability of the configuration.

Porous flow model for cellular foams

1990 ◽  
Vol 25 (2) ◽  
pp. 236-239 ◽  
Author(s):  
K. B. Kann
Keyword(s):  
Flow Model ◽  
Porous Flow ◽  
Cellular Foams

3D SPH porous flow model for wave interaction with permeable structures

2018 ◽  
Vol 75 ◽  
pp. 223-233 ◽  
Author(s):  
Hongjie Wen ◽  
Bing Ren ◽  
Guoyu Wang
Keyword(s):  
Flow Model ◽  
Wave Interaction ◽  
Porous Flow

scholarly journals ON 3-DIMENSIONAL STABILITY OF RESHAPING BREAKWATERS

1988 ◽  
Vol 1 (21) ◽  
pp. 169 ◽  
Author(s):  
H.F. Burcharth ◽  
Peter Frigaard
Keyword(s):  
Large Volume ◽  
Dimensional Stability ◽  
Wave Action ◽  
Rock Material ◽  
3 Dimensional ◽  
Specialized Equipment ◽  
Rubble Mound ◽  
Rubble Mound Breakwaters

The paper deals with the 3-dimensional stability of the type of rubble mound breakwaters where reshaping of the mound due to wave action is foreseen in the design. Such breakwaters are commonly named sacrificial types and berm types. The latter is due to the relatively large volume of armour stones placed in a seaward berm. However, as also conventional armoured breakwaters sometimes do contain a berm it is assumed that a better and more ambiguous designation would be "reshaping" mound breakwaters. The principle of reshaping breakwaters is to use relatively fine rock material which will then be eroded to S-shape profiles if sufficient amount of material is provided, Fig. 1. This type of breakwater can be constructed and maintained without the use of expensive specialized equipment. For a detailed discussion see Baird et al., 1984.

scholarly journals Numerical Investigation on Air Film Fusion of Pressure-Equalizing Exhaust around Shoulder Ventilation of Submarine-Launched Vehicle

2021 ◽  
Vol 10 (1) ◽  
pp. 39
Author(s):  
Yao Shi ◽  
Jinyi Ren ◽  
Shan Gao ◽  
Guang Pan
Keyword(s):  
Numerical Calculation ◽  
Surface Pressure ◽  
Flow Model ◽  
Axial Direction ◽  
Underwater Vehicle ◽  
Hydrodynamic Characteristics ◽  
Circumferential Fusion ◽  
Numerical Calculation Method ◽  
Rng Turbulence Model ◽  
Air Film

In order to study the influence of pressure-equalizing exhaust at the shoulder of a submarine-launched vehicle on the surface hydrodynamic characteristics, this paper establishes a numerical calculation method based on the VOF multiphase flow model, the standard RNG turbulence model and the overset mesh technology; the method compares the fusion characteristics of the air film at the shoulder of the underwater vehicle, as well as the distribution of surface pressure along the vehicle’s axial direction. The results show that the approximate isobaric zone derived from air film fusion can greatly improve the hydrodynamic characteristics of the vehicle, and the number of venting holes determines the circumferential fusion time of the air film. The greater the number of venting holes, the sooner circumferential fusion starts.

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