Hydrodynamic Mass Matrix for a Multibodied System

1974 ◽  
Vol 96 (2) ◽  
pp. 611-618
Author(s):  
G. R. Sharp ◽  
W. A. Wenzel

A matrix technique is developed herein for generating the hydrodynamic mass matrix associated with a multimass system immersed in a liquid environment. The technique assumes that the liquid environment may be represented by a series of flow-channels and nodes. Flow-channels are introduced in the region between surfaces of neighboring solids, and nodes are used to connect two or more flow channels. It is assumed that the solid bodies undergo unidirectional motion and that potential flow theory is applicable. Equations for fluid flow in a variable area flow-channel are obtained by first developing the governing equations for fluid flow in a channel bounded by two parallel surfaces which may move in translation both perpendicular and parallel to the direction of flow. The continuity equation is then developed for an arbitrary node, and the general matrix equation for computing hydrodynamic mass obtained by applying the developed equations to a particular problem.

2018 ◽  
Vol 7 (4.35) ◽  
pp. 148 ◽  
Author(s):  
Nur Irmawati Om ◽  
Rozli Zulkifli ◽  
P. Gunnasegaran

The influence of utilizing different nanofluids types on the liquid cold plate (LCP) is numerically investigated. The thermal and fluid flow performance of LCP is examined by using pure ethylene glycol (EG), Al2O3-EG and CuO-EG. The volume fraction of the nanoparticle for both nanofluid is 2%. The finite volume method (FVM) has been used to solved 3-D steady state, laminar flow and heat transfer governing equations. The presented results indicate that Al2O3-EG able to provide the lowest surface temperature of the heater block followed by CuO-EG and EG, respectively. It is also found that the pressure drop and friction factor are higher for Al2O3-EG and CuO-EG compared to the pure EG.


2006 ◽  
Vol 13 (06) ◽  
pp. 795-802 ◽  
Author(s):  
DANIEL LIM ◽  
ERNA GONDO SANTOSO ◽  
KIM MING TEH ◽  
STEPHEN WAN ◽  
H. Y. ZHENG

Silicon has been widely used to fabricate microfluidic devices due to the dominance of silicon microfabrication technologies available. In this paper, theoretical analyses are carried out to suggest suitable laser machining parameters to achieve required channel geometries. Based on the analyses, a low-power CO 2 laser was employed to create microchannels in Acrylic substrate for the use of manufacturing an optical bubble switch. The developed equations are found useful for selecting appropriate machining parameters. The ability to use a low-cost CO 2 laser to fabricate microchannels provides an alternative and cost-effective method for prototyping fluid flow channels, chambers and cavities in microfluidic lab chips.


2010 ◽  
Vol 132 (11) ◽  
Author(s):  
A. Arikoglu ◽  
G. Komurgoz ◽  
I. Ozkol ◽  
A. Y. Gunes

The present work examines the effects of temperature and velocity jump conditions on heat transfer, fluid flow, and entropy generation. As the physical model, the axially symmetrical steady flow of a Newtonian ambient fluid over a single rotating disk is chosen. The related nonlinear governing equations for flow and thermal fields are reduced to ordinary differential equations by applying so-called classical approach, which was first introduced by von Karman. Instead of a numerical method, a recently developed popular semi numerical-analytical technique; differential transform method is employed to solve the reduced governing equations under the assumptions of velocity and thermal jump conditions on the disk surface. The combined effects of the velocity slip and temperature jump on the thermal and flow fields are investigated in great detail for different values of the nondimensional field parameters. In order to evaluate the efficiency of such rotating fluidic system, the entropy generation equation is derived and nondimensionalized. Additionally, special attention has been given to entropy generation, its characteristic and dependency on various parameters, i.e., group parameter, Kn and Re numbers, etc. It is observed that thermal and velocity jump strongly reduce the magnitude of entropy generation throughout the flow domain. As a result, the efficiency of the related physical system increases. A noticeable objective of this study is to give an open form solution of nonlinear field equations. The reduced recurative form of the governing equations presented gives the reader an opportunity to see the solution in open series form.


2020 ◽  
Vol 16 (4) ◽  
pp. 487-492
Author(s):  
Nurazleen Abdul Majid ◽  
Nurul Farahain Mohammad ◽  
Abdul Rahman Mohd Kasim ◽  
Sharidan Shafie

In recent decades, micropolar fluid has been one of the major interesting research subjects due to the numerous applications such as blood, paint, body fluid, polymers, colloidal fluid and suspension fluid. However, the behavior of micropolar fluid flow over a permeable stretching surface of another quiescent fluid with a heavier density of micropolar fluid under the condition of mixed convection is still unknown. Thus, the current work aims to investigate numerically the mixed convection of micropolar fluid flow over a permeable stretching surface of another quiescent fluid. In this research, the similarity transformation is implemented to reduce the boundary layer governing equations from partial differential equations to a system of nonlinear ordinary differential equations. Then, this model is solved numerically using shooting technique with Runge-Kutta-Gill method and applied in Jupyter Notebook using Python 3 language. The behavior of micropolar fluid in terms of velocity, skin friction, microrotation and temperature are analyzed.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Gamal M. Abdel-Rahman Rashed

Chemical entropy generation and magnetohydrodynamic effects on the unsteady heat and fluid flow through a porous medium have been numerically investigated. The entropy generation due to the use of a magnetic field and porous medium effects on heat transfer, fluid friction, and mass transfer have been analyzed numerically. Using a similarity transformation, the governing equations of continuity, momentum, and energy and concentration equations, of nonlinear system, were reduced to a set of ordinary differential equations and solved numerically. The effects of unsteadiness parameter, magnetic field parameter, porosity parameter, heat generation/absorption parameter, Lewis number, chemical reaction parameter, and Brinkman number parameter on the velocity, the temperature, the concentration, and the entropy generation rates profiles were investigated and the results were presented graphically.


Fractals ◽  
2018 ◽  
Vol 26 (02) ◽  
pp. 1840001 ◽  
Author(s):  
NA HUANG ◽  
YUJING JIANG ◽  
RICHENG LIU ◽  
YUXUAN XIA

The effect of model size on fluid flow through fractal rough fractures under shearing is investigated using a numerical simulation method. The shear behavior of rough fractures with self-affine properties was described using the analytical model, and the aperture fields with sizes varying from 25 to 200[Formula: see text]mm were extracted under shear displacements up to 20[Formula: see text]mm. Fluid flow through fractures in the directions both parallel and perpendicular to the shear directions was simulated by solving the Reynolds equation using a finite element code. The results show that fluid flow tends to converge into a few main flow channels as shear displacement increases, while the shapes of flow channels change significantly as the fracture size increases. As the model size increases, the permeability in the directions both parallel and perpendicular to the shear direction changes significantly first and then tends to move to a stable state. The size effects on the permeability in the direction parallel to the shear direction are more obvious than that in the direction perpendicular to the shear direction, due to the formation of contact ridges and connected channels perpendicular to the shear direction. The variances of the ratio between permeability in both directions become smaller as the model size increases and then this ratio tends to maintain constant after a certain size, with the value mainly ranging from 1.0 to 3.0.


Author(s):  
Abbas Hazbavi ◽  
Sajad Sharhani

In this study, the hydrodynamic characteristics are investigated for magneto-micropolar fluid flow through an inclined channel of parallel plates with constant pressure gradient. The lower plate is maintained at constant temperature and upper plate at a constant heat flux. The governing equations which are continuity, momentum and energy are are solved numerically by Explicit Runge-Kutta. The effect of characteristic parameters is discussed on velocity and microrotation in different diagrams. The nonlinear parameter affected the velocity microrotation diagrams. An increase in the value of Hartmann number slows down the movement of the fluid in the channel. The application of the magnetic field induces resistive force acting in the opposite direction of the flow, thus causing its deceleration. Also the effect of pressure gradient is investigated on velocity and microrotation in different diagrams.


2019 ◽  
Vol 11 (1) ◽  
pp. 168781401882332
Author(s):  
Yang Yang ◽  
Wuhuai Yan ◽  
Jinrui Wang

In this article, Timoshenko’s beam model is established to investigate the wave propagation behaviors for a fluid-conveying carbon nanotube when employing the nonlocal stress–strain gradient coupled theory and nonlocal fluid theory. The governing equations of motion for the carbon nanotube are derived. The small-scale influences induced by the nanotube are simulated by nonlocal and strain gradient effects, and the scale effect induced by fluid flow is first investigated applying nonlocal fluid theory. Numerical results obtained by solving the governing equations indicate that the nonlocal effect induced by the nanotube leads to wave damping and a decrease in stiffness, while the strain gradient effect contributes to wave promotion and an enhancement in stiffness. The scale effect caused by the inner fluid only leads to a decay for a high-mode wave since there is no influence from fluid flow on the low-mode wave. The numerical solution is validated by comparing with Monte Carlo simulation and interval analysis method.


Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 580 ◽  
Author(s):  
Zahra Abdelmalek ◽  
Mohammad Yaghoub Abdollahzadeh Jamalabadi

Micromixers are significant segments inside miniaturized scale biomedical frameworks. Numerical investigation of the effects of galloping cylinder characteristics inside a microchannel Newtonian, incompressible fluid in nonstationary condition is performed. Governing equations of the system include the continuity equation, and Navier–Stokes equations are solved within a moving mesh domain. The symmetry of laminar entering the channel is broken by the self-sustained motion of the cylinder. A parameter study on the amplitude and frequency of passive moving cylinder on the mixing of tiny particles in the fluid is performed. The results show a significant increase to the index of mixing uses of the galloping body in biomedical frameworks in the course of micro-electromechanical systems (MEMS) devices.


2018 ◽  
Vol 388 ◽  
pp. 344-349
Author(s):  
D.V. Jayalakshmamma ◽  
P.A. Dinesh ◽  
D.V. Chandrashekhar

The numerical study of axi-symmetric, steady flow of an incompressible micropolar fluid past an impervious sphere is presented by assuming uniform flow far away from the sphere. The continuity, linear and angular momentum equations are considered for incompressible micropolar fluid in accordance with Eringen. The governing equations of the physical problem are transformed to ordinary differential equation with variable co-efficient by using similarity transformation method. The obtained differential equation is then solved numerically by assuming the shooting technique. The effect of coupling and coupling stress parameter on the properties of the fluid flow is studied and demonstrated by graphs.


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