scholarly journals Impacts of the Properties Heterogeneity on 3D Magnetic Dusty Nanofluids Flow Within Cubic Porous Enclosures Contain Isothermal Cylinders

2021 ◽  
Author(s):  
Z. Z. Rashed
Keyword(s):  
Porous Medium ◽  
Three Dimensional ◽  
Thermal Conditions ◽  
Circular Cylinders ◽  
Nanofluid Flow ◽  
Two Phase ◽  
Flow Domain ◽  
Isothermal Cylinders ◽  
The Right ◽  
Volume Method

Abstract This paper examines the controlling of the three dimensional dusty nanofluid flow using the two circular cylinders having different thermal conditions. The cylinders are located in the middle area while the location of the right cylinder is changeable. The 3D cubic flow domain is filled by a non-Darcy porous medium and a magnetic field in Z-direction is taken place. The non-homogeneous two phase model of the nanofluid is applied while the permeability and thermal conductivity of the porous medium are assumed heterogonous. The current situation is represented by two systems of the equations for the nanofluid and dusty phases. The solutions methodology is depending on the 3D SIMPLE scheme together with the finite volume method. The major outcomes indicating to that the flow can be well controlled using the inner isothermal cylinders. Also, the cases of the heterogeneity in \(X-Y\) and \(X-Z\) directions give the lowest values of \({Nu}_{av}\).

The 3D Numerical Simulation of Flow Field on Y-Shape Flaring Gate Piers Combined with Stepped Spillway

2013 ◽  
Vol 864-867 ◽  
pp. 2200-2206
Author(s):  
Ju Rui Yang ◽  
Xiao Xia Hou ◽  
Qiu Yue Zhang
Keyword(s):  
Water Vapor ◽  
Flow Velocity ◽  
Three Dimensional ◽  
Iterative Solution ◽  
Average Error ◽  
Stepped Spillway ◽  
Two Phase ◽  
Vof Model ◽  
The Right ◽  
Volume Method

The energy dissipater of stepped spillway combined with flaring gate pier is widely used in china's hydraulic engineering. The finite volume method is applied to discrete analysis, with the RNG turbulence model and VOF model of water vapor two-phase, iterative solution of geometry reconstruction format unsteady flow to generate free surface. Adopting structured grid for geometric shape, numerically simulated the water vapor two-phase flow from the reservoir to stilling basin. The parabolic water-vapor interface , overall flow pattern, water wings, section depth and other hydraulic characteristics was produced by simulating the three-dimensional flow field.Compared the simulated results of water depth, flow velocity in stilling pool, the board pressure with experiment data, the average error is: the left side depth of 3 # table hole of 7.1%, and the right of 7.4%; the underside flow velocity of 3 # table hole of 5%;1 # table hole stilling pool board pressure of 7.6%,3 # table hole stilling pool board pressure of 6.6%.

Peristaltic Carreau-Yasuda nanofluid flow and mixed heat transfer analysis in an asymmetric vertical and tapered wavy wall channel

2020 ◽  
Vol 1 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Mohammad Hatami ◽  
◽  
D Jing ◽  
Keyword(s):  
Heat Transfer ◽  
Least Square Method ◽  
Weissenberg Number ◽  
Least Square ◽  
Heat Transfer Analysis ◽  
Phase Method ◽  
Nanofluid Flow ◽  
Two Phase ◽  
Nanoparticles Concentration ◽  
The Right

In this study, two-phase asymmetric peristaltic Carreau-Yasuda nanofluid flow in a vertical and tapered wavy channel is demonstrated and the mixed heat transfer analysis is considered for it. For the modeling, two-phase method is considered to be able to study the nanoparticles concentration as a separate phase. Also it is assumed that peristaltic waves travel along X-axis at a constant speed, c. Furthermore, constant temperatures and constant nanoparticle concentrations are considered for both, left and right walls. This study aims at an analytical solution of the problem by means of least square method (LSM) using the Maple 15.0 mathematical software. Numerical outcomes will be compared. Finally, the effects of most important parameters (Weissenberg number, Prandtl number, Brownian motion parameter, thermophoresis parameter, local temperature and nanoparticle Grashof numbers) on the velocities, temperature and nanoparticles concentration functions are presented. As an important outcome, on the left side of the channel, increasing the Grashof numbers leads to a reduction in velocity profiles, while on the right side, it is the other way around.

Verification of STACS-VOF Based Two-Phase Flow Model for Interfacial Flows

2012 ◽  
Vol 212-213 ◽  
pp. 1098-1102
Author(s):  
Bin Deng ◽  
Chang Bo Jiang ◽  
Zhi Xin Guan ◽  
Chao Shen
Keyword(s):  
Flow Model ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Test Cases ◽  
Phase Flow ◽  
Interfacial Flows ◽  
Governing Equations ◽  
Two Phase ◽  
Resolution Scheme ◽  
Volume Method

The numerical calculation and simulation of gas-liquid two-phase flows with interfacial deformations have nowadays become more and more popular issues in various scientific and industrial fields. In this study, a three-dimensional gas-liquid two-phase flow numerical model is presented for investigating interfacial flows. The finite volume method was used to discretize the governing equations. A High-resolution scheme of VOF method (STACS) is applied to capture the free surface. The paper outlines the methodology of STACS and its validation against three typical test cases used to verify its accuracy. The results show the STACS-VOF gives very satisfactory results for three-dimensional two-phase interfacial flows problem, and this scheme performs more accurate and less diffusive preserving interface sharpness and boundedness.

Numerical Analysis of Erosive Wear on the Guide Vanes of a Francis Turbine

2015 ◽  
Vol 741 ◽  
pp. 531-535
Author(s):  
Hong Ming Zhang ◽  
Li Xiang Zhang
Keyword(s):  
Numerical Analysis ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Erosive Wear ◽  
Francis Turbine ◽  
Two Phase ◽  
Guide Vanes ◽  
Flow Equations ◽  
Sand Erosion ◽  
Volume Method

The paper presents the numerical analysis of erosive wear on the guide vanes of a Francis turbine using CFD code. The 3-D turbulent particulate-liquid two-phase flow equations are employed in this study. The computing domain is discretized with a full three-dimensional mesh system of unstructured tetrahedral shapes. The finite volume method is used to solve the governing equations and the pressure-velocity coupling is handled via a Pressure Implicit with Splitting of Operators (PISO) procedure. Simulation results have shown that the volume fraction of sand at the top of the guide vanes is higher than others and the maximum of volume fraction of sand is at same location with the maximum of sand erosion rate density. The erosive wear is more serious at the top of the guide vanes.

Passive Tracer Validity for Cooling Effectiveness Through Flow Computation in a Turbine Rim Seal Environment

2011 ◽  
Author(s):  
Guillaume Boutet-Blais ◽  
Julie Lefrancois ◽  
Guy Dumas ◽  
Steve Julien ◽  
Jean-Francois Harvey ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Thermal Conditions ◽  
Operating Conditions ◽  
Passive Tracer ◽  
Turbine Stage ◽  
Cooling Effectiveness ◽  
Through Flow ◽  
Purge Flow ◽  
Unsteady Rans ◽  
The Right

This paper reports the first phase of an investigation aiming to determine the validity of using a CO2 marker in cold rig experiments to characterize the thermal performances of turbine rim seals under actual engine operating conditions. For comparison purposes, simulations are carried out for two sets of operating conditions, namely cold rig (with uniform low temperature) and real turbine thermal conditions (high temperature gaspath and cold purge flow). Sealing effectiveness based on the CO2 diagnostic under cold rig operating conditions is compared to sealing effectiveness based on the computed temperature field under real engine temperature conditions. Unsteady RANS simulations with different purge flow rates are performed. Tested geometries include a 180° domain presenting a simplified rim seal geometry with no vanes nor blades in the gaspath, and a 24° sector of a complete turbine stage including 3 vanes and 4 blades. Three-dimensional flow structures known to affect ingestion are found with both geometries but appear to be sensitive to the differences in operating conditions. Indeed, their circumferential number and strength differ between the two scenarios of conditions. Furthermore, it is found that the cold rig predictor tends to slightly overestimate the sealing effectiveness, while providing nonetheless the right trends and reasonably accurate average values in levels of actual sealing. At this stage of the investigation, we conclude that it seems adequate to use a passive tracer in cold rig experiments to compare performances of rim seal designs.

Three-Dimensional Numerical Simulation of Fluid with Sparse Particles' Erosion to Pipelines

2013 ◽  
Vol 805-806 ◽  
pp. 1785-1789
Author(s):  
Chang Bin Wang ◽  
Miao Wang ◽  
Xiao Xu Li ◽  
Yu Liu ◽  
Jie Nan Dong
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Flow Model ◽  
Particle Distribution ◽  
Three Dimensional ◽  
Two Phase ◽  
Wear Area ◽  
Computational Fluid Dynamics Cfd ◽  
Set Up ◽  
Volume Method

A three dimensional fluid flow model was set up in this paper, based on the computational fluid dynamics (CFD) and the elasticity theory. Using the finite volume method, a 120° bend was taken as a research object to simulate the erosion to the wall of fluid with sparse particles, finally, to determine the most severe wear areas.At the same time, the distribution of two-phase flows pressure and velocity was analyzed in 45° and 90° bends, then tracked the trajectory of the particles. The results show that the 90°bend has the smallest wear area and particle distribution or combination property is the best.

Sign in / Sign up

Export Citation Format

Share Document