Begell House Inc.
International Journal of Fluid Mechanics Research
FMR
2152-5102
32
1
2005
Modeling of Multi-Species Contaminant Transport with Spatially-Dependent Dispersion and Coupled Linear/Non-Linear Reactions
1-20
Ali J.
Chamkha
Department of Mechanical Engineering, Prince Sultan Endowment for Energy and
Environment, Prince Mohammad Bin Fahd University, Al-Khobar 31952, Kingdom of Saudi
Arabia; RAK Research and Innovation Center, American University of Ras Al Khaimah, United Arab Emirates, 10021
A one-dimensional four-species sequential reactive contaminant transport model with spatially-dependent dispersion coefficient and transport velocity is considered. The sequential reactions which take place are assumed to be nonlinear and of arbitrary order. Two types of variations of the dispersion coefficient with the downstream distance are considered. The first type assumes that the dispersivity increases as a power function with distance while the other assumes an exponentially-increasing function. The transport velocity is also assumed to follow a general power-law function with the space coordinate. The general governing equations are non-dimensionalized and solved numerically by an efficient implicit iterative tri-diagonal finite-difference method. Comparisons with previously published analytical solutions for special cases of the problem are performed and found to be in excellent agreement. A parametric study of all physical parameters is conducted and the results are presented graphically to illustrate interesting features of the solutions. It is found that the chemical reaction order, the scale-dependent dispersion coefficient and the non-uniform transport velocity have significant effects on the multi-species concentration profiles.
Non-Darcy Free Convective Heat Transfer from a Plate in a Porous Medium
21-38
Mohamed F.
El-Amin
Mathematics Department, Aswan Faculty of Science, South Valley University, Aswan, 81258; King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
Rama Subba Reddy
Gorla
Department of Mechanical Engineering, Cleveland State University, Cleveland, OH, 44115 USA; Department of Mechanical Engineering, University of Akron, Akron, Ohio 44325, USA; Department of Mechanical & Civil Engineering, Purdue University Northwest, Westville, IN 46391, USA
In this article, the problem of buoyancy-induced flow over a horizontal or a vertical flat plate embedded in a fluid-saturated non-Darcy porous medium is studied. Forchheimer extension is considered in the flow equations. Similarity solutions for the transformed governing equations are obtained, with a prescribed variable surface temperature or variable surface heat flux, for each position of the plate. Values of the slip velocity, Nusselt number for variable surface temperature as well as excess surface temperature for variable surface heat flux, and the total heat transfer as well as the momentum flux, which are plotted in figures, have been presented for different values of the given parameters for the two cases of horizontal and vertical plates.
Free Convection Flow of Two Immiscible Viscous Liquids Through Parallel Permeable Beds: Use of Brinkman Equation
39-56
Harmindar S.
Takhar
Engineering Department, Manchester Metropolitan University, Oxford Rd., Manchester, M15GD, UK
The present paper deals with an analytical study of free convection in fully developed laminar, free convection flow of two viscous, immiscible, incompressible liquids bounded above and blow by two parallel naturally permeable beds of high porosity and finite thickness. The momentum transfer in the free flow region is governed by Navier-Stokes equations and the flow in the porous medium is governed by Brinkman equation. The flow domain is divided into four regions and exact solutions of the momentum and energy equations are obtained for each region under appropriate matching and boundary conditions. The effects of various parameters on the velocity and temperature fields are discussed with the help of graphs while the effects on skin-friction and heat transfer are discussed with the help of tables.
An Experimental Investigation of Flow in an Elbow Type Draft Tube with Swirl
57-78
T. Ravi
Sundar
Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai-600036, India
E. G.
Tulapurkara
Department of Aerospace Engineering, Indian Institute of Technology Madras, Chennai-600036, India
V.
Balabaskaran
Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai-600036, India
The static pressure recovery and velocity field are investigated inside an elbow type draft tube model in wind tunnel experiments. Swirl intensity of the inlet flow is varied from 0.0 to 0.8 for static pressure measurements and from 0.0 to 0.35 for those of velocity field. Results show that for moderate swirl intensity (≈ 0.2) the static pressure recovery is higher than that for uniform inlet flow. Investigations at Reynolds number varying from 0.4 · 105 to 1.6 · 105 indicate that the static pressure recovery is independent of Reynolds numbers beyond a value of 105. Radial distributions of all three velocity components at the inlet station and isovelocity contours at other stations in the draft tube are presented at various swirl intensities. These could provide experimental data for validation of computer codes.
Hydrodynamical, Mechanical, and Structural Properties of Fibrous Drain Filters
79-97
N. G.
Bugay
Institute of Hydromechanics of National Academy of Sciences of Ukraine, Kyiv, Ukraine
A. I.
Krivonog
Institute of Hydromechanics of National Academy of Sciences of Ukraine, Kyiv, Ukraine
V. V.
Krivonog
Institute of Hydromechanics of National Academy of Sciences of Ukraine, Kyiv, Ukraine
N. G.
Pivovar
Institute of Hydromechanics of National Academy of Sciences of Ukraine, Kyiv, Ukraine
V. L.
Fridrihson
Institute of Hydromechanics of National Academy of Sciences of Ukraine, Kyiv, Ukraine
The paper presents results of studies in mechanical properties, filtration characteristics, protective abilities, and structural properties of fibrous materials made of mineral or polymeric fibers; the latter are used as filters in horizontal, vertical, and radial drainage that protects cultivated lands, town territories, and particular objects from underflooding. Results are presented that were obtained by studying the drainage intake ability depending on the drain design, drainage construction methods, and properties of drained soil. A calculation procedure is suggested together with recommendations needed to design the drainage properly. The paper gives recommendations on technologies of construction of fibrous filters and drainage based on them, in various groundwater conditions and with various chemical properties of the water environment. Also, the extent of implementation and results of the long-term of field investigations are described; these demonstrate the efficacy of the new drainage designs, show their technical and economic efficiency in reclamation construction and various fields of water engineering.
Hydraulic Properties of Branching Pipelines with Permeable Walls
98-109
N. N.
Kizilova
V. N. Karazin Kharkiv National University, Ukraine
Stationary motion of a viscous incompressible liquid through a cylindrical tube with rigid permeable wall as applied to sap flow through the conducting system of plant leaves is investigated. As the liquid moves it percolates through the wall into the surrounding medium where the hydrostatic pressure is kept at a constant level. The outflow consists of two components; one depends on the pressure p inside the tube and the other is independent of p (passive and active components of the water transport, respectively). The analysis of the total hydraulic resistance of the system and distribution heterogeneity of the liquid inside the medium is carried out. For some outflow conditions the parameters of an optimal tube that provides liquid delivery at minimal total energy expenditures are investigated. It is shown that solutions of the optimization problem for the tubes both with permeable and impermeable walls lead to similar geometrical relations. In that way various hydromechanical factors can underlie similarities in construction of the long-range water transport systems in plant and animal tissues.
Oscillation of a Submerged Axisymmetric Shell-Like Jet
110-122
A. A.
Nazarenko
I. I. Mechnikov Odessa National University, Odessa, Ukraine
Yu. M.
Dudzinskii
Odessa National Polytechnic University, Odessa, Ukraine
An axially symmetric hydrodynamic acoustic source, simulated as an elastic underwater jet shell, is under consideration. The basic frequency of an acoustic signal is obtained as a function of the working fluid properties, geometric and hydrodynamic parameters of the jet. The feasibility of controlling the signal frequency by changing the fluid elasticity as a function of hydrostatic pressure is demonstrated.