Begell House Inc.
International Journal of Fluid Mechanics Research
FMR
2152-5102
36
1
2009
Nonlinear Study of Magnetohydrodynamic Laminar Flow Between Permeable Disks Using CESS
1-29
N.
Rudraiah
National Research Institute for Applied Mathematics, 492/G, 7th Cross, 7th Block (West), Jayanagar, Bangalore 560 082, and UGC-DSA Centre in Fluid Mechanics, Department of Mathematics, Bangalore University, Bangalore 560 001, India
A two-dimensional, steady, laminar flow of an electrically conducting incompressible, viscous fluid between two parallel permeable disks in the presence of a transverse magnetic field is studied using the computer-extended series solution (CESS). It is shown, using suitable analysis that the radius of convergence (ROC) is greatly influenced by the parameters of the problem, which renders the classical regular perturbation technique (RPT) ineffective for values of the perturbation parameter beyond the ROC. The ROC is shown to decrease with an increase in the value of the interaction parameter N. The skin friction coefficient and coefficient of pressure distribution are evaluated for different values of suction/injection Reynolds number R and magnetic interaction parameter N. The advantages of using the CESS method over the RPT and numerical techniques are discussed.
Unsteady Boundary Layer Flow Induced by Accelerating Motion Near the Rear Stagnation Point in a Micropolar Fluid
30-42
Y. Y.
Lok
Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka 75450 Ayer Keroh, Melaka, Malaysia
Norsarahaida Saidina
Amin
Department of Mathematics, Faculty of Science, University Technology Malaysia, 81300 Skudai, Johor, Malaysia
Ioan
Pop
Department of Applied Mathematics, Babes-Bolyai University, 400084 Cluj-Napoca, Romania
The unsteady boundary layer flow of a micropolar fluid induced by a two-dimensional body, which is started impulsively from rest, is studied in this paper. The variation with time t of the external stream V(t) is assumed to be of the form V(t) = 1 − exp(−αtm), where α ≥ 0 means a coefficient of acceleration and m is an arbitrary integral value. The problem is formulated for the flow at the rear stagnation point on an infinite plane wall. Numerical solutions of the unsteady boundary layer equations are obtained using an implicit finite-difference scheme known as the Keller's box method. Results are given for the velocity and microrotation profiles, as well as for the dimensionless time elapsed before the boundary layer begins to separate from the wall. It is found that the dimensionless time elapsed before separation takes place is lower for a micropolar fluid (K ≠ 0) than for a Newtonian fluid (K = 0), where K denotes the micropolar or material parameter.
Pulsatile Casson Fluid Flow Through a Stenosed Bifurcated Artery
43-63
Sachin
Shaw
Botswana International University of Science and Technology
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
P. V. S. N.
Murthy
Department of Mathematics, Indian Institute of Technology, Kharagpur, West Bengal, 721302, India
Chiu-On
Ng
Department of Mechanical Engineering, The University of Hong Kong, Pokfulam, Hong Kong, People's Republic of China
Flow of a pulsatile Casson fluid through a stenosed bifurcated artery has been investigated in this study. The arteries forming bifurcation are assumed to be symmetric and straight cylinders of finite length and it is also assumed that the outer and inner walls of the bifurcated artery undergo wall motion. The governing momentum equation is written in terms of the shear stress, and the resulting equation along with the initial and boundary conditions are solved numerically. The crucial parameters that influence the flow in the bifurcated artery are the radius of the parent artery and the length of the stenosis in addition to the curvature at the different sections of the bifurcated tube. Flow variables are computed at various locations in the parent and daughter arteries. The velocity is derived from the shear stress using the Casson fluid model. The velocity and the volumetric flow in both the parent and daughter arteries are computed for various parameters. It is observed in both the femoral and coronary arteries that the variation of axial velocity and the flow rate with yield stress is uniform, and flow rate in the daughter artery shows more oscillations with the Casson fluid model than that with the Newtonian one. The effect of flow rheology on the velocity pattern in the daughter artery is greater than in the parent artery. The axial velocity and flow rate are greater in the coronary artery than in the femoral artery, and the wall shear stress in the parent artery increases due to the stenosis.
Design and Development of Electromagnetic Shockwave Control Experiment
64-79
Xiaoqing (Cathy)
Qian
Department of Mechanical Engineering, P.O. Box 1163, Alabama A&M University, Huntsville, AL 35762, USA
Zhengtao
Deng
Department of Mechanical Engineering, P.O. Box 1163, Alabama A&M University, Huntsville, AL 35762, USA
Ron
Litchford
NASA Marshall Space Flight Center, Huntsville, AL 35812, USA
John
Foote
NASA Marshall Space Flight Center, Huntsville, AL 35812, USA
John
Lineberry
LyTec LLC, Tullahoma, Tennessee 37388, USA
V. A.
Bityurin
LyTec LLC, Tullahoma, Tennessee 37388, USA
Initial development of an experimental program on electromagnetic control of shockwave was presented. This experiment was aimed to investigate the validity of the potential MHD flow control for hypersonic flight vehicle. Experimental arc heater facility modification, test model design and analysis, cradle design and preliminary experimental results were reported. Shockwave locations for high Mach number ionized flows over a spherical nose-cone with cylindrical body and with an applied magnetic field was reported. Results provide excellent platform to simulate electromagnetic shockwave control for the hypersonic flight by introducing ionization seed into the airflow and generates artificial re-entry conditions at reduced Mach number.
Incipient Motion Criterion for Plane Bed Channels
80-95
Achanta Ramakrishna
Rao
Department of Civil Engineering, Indian Institute of Science, Bangalore-560012, India
Bimlesh
Kumar
Assistant Professor. Department of Civil Engineering, Indian Institute of Technology, Guwahati-781039, India
A new criterion for incipient motion relating Froude number and friction slope with the relative density of sediment particles in fluid is presented in an explicit manner without involving particle size. The new criterion also explains the resistance characteristics at incipient motion. Based on the criterion developed, a procedure to design the plane and stable alluvial channel beds under uniform flow conditions is given. In this procedure any two of the four basic design variables viz., water discharge, flow depth, channel slope and bed material size are sufficient to evaluate the remaining two variables in such a way that the bed particles are stable.