Magnetohydrodynamic boundary layer control with suction or injection

Wu, Yung‐Kuang

doi:10.1063/1.1662531

Cited by 17 publications

(6 citation statements)

References 7 publications

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“…Let t 0 be a minimum of f ′ with f a solution of (1). Using the equation (1) and the fact that f ′′ (t 0 ) = 0, we obtain that…”

Section: And Thus a Contradictionmentioning

confidence: 99%

“…Boundary layer flow of an electrically conducting fluid over moving surfaces emerges in a large variety of industrial and technological applications. It has been investigated by many researchers, Wu [1] has studied the effects of suction or injection on a steady two-dimensional MHD boundary layer flow on a flat plate, Takhar et al [2] studied a MHD asymmetric flow over a semi-infinite moving surface and numerically obtained the solutions. An analysis of heat and mass transfer characteristics in an electrically conducting fluid over a linearly stretching sheet with variable wall temperature was investigated by Vajravelu and Rollins [3].…”

Section: Introductionmentioning

confidence: 99%

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On the similarity solutions for a steady MHD equation

Hoernel

2008

Communications in Nonlinear Science and Numerical Simulation

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In this paper, we investigate the similarity solutions for a steady laminar incompressible boundary layer equations governing the magnetohydrodynamic (MHD) flow near the forward stagnation point of two-dimensional and axisymmetric bodies. This leads to the study of a boundary value problem involving a third order autonomous ordinary differential equation. Our main results are the existence, uniqueness and nonexistence for concave or convex solutions. MSC: 34B15, 34C11, 76D10 PACS: 47.35.Tv, 47.65.d, 47.15.Cb

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“…Let t 0 be a minimum of f ′ with f a solution of (1). Using the equation (1) and the fact that f ′′ (t 0 ) = 0, we obtain that…”

Section: And Thus a Contradictionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

On the similarity solutions for a steady MHD equation

Hoernel

2008

Communications in Nonlinear Science and Numerical Simulation

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“…Although the main focus of the present study is on the application of MHD in marine propulsion systems, the magneto-hydrodynamic interactions and forces is important in many other fields including aerospace, astrophysics (Stenflo 2015 andSkala et al 2015), and metallurgy, and can play a decisive role in the field of modern technologies such as nanotechnology (Zhang et.al 2007) and fusion reactors (Dhanai et.al, 2015). Even in the field of fluid dynamics, in addition to the propulsion system, MHD is used in other areas including MHD generators and pumps (Smy, 1961;Kantrowitz, 1962) and flow control (Popov, 1971;Wu, 1973).…”

Section: Introductionmentioning

confidence: 99%

Preliminary Experimental Investigation on a Low Profile Magneto-Hydrodynamic Propulsive Blanket, Considering Plasma Generation

Chekab

Ghadimi

Sheikholeslami

et al. 2018

JAFM

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The use of magnetohydrodynamic (MHD) blanket propulsion system in ships, even with low efficiencies, has particular benefits that can make them an appropriate option for the marine designers. Accordingly, any attempt to increase the efficiency of these systems requires full recognition of their performance in different conditions. In the present study, as a continuation of previous numerical works by the current authors, a magneto-hydrodynamic blanket propulsion system has been built and experimentally studied through examining the MHD forces produced in different voltages. Copper and gold have been used and compared as electrodes and the high advantage of gold has been demonstrated. The effect of electrolysis on the behavior of the blanket is analyzed. It has been demonstrated that although electrolysis restricts high currents in lower voltages (lower than ~140V) and the saturation of hydrogen decreases the MHD forces due to low electrical current (~140V up to ~160V), the saturation of hydrogen around cathode at high voltages (more than ~160V), makes a dielectric barrier which soon breaks down and make the production of plasma possible, which in turn highly increases the thrust force of the MHD blanket. Therefore, three regimes have been introduced and described for the MHD blanket; the electrolysis regime, the transition regime, and the hot plasma regime. Based on the obtained results, one may conclude that the present results have offered good evidence about the possibility of increasing the MHD blanket performance through plasma production in water.

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“…6 Also, the term ''magnetohydrodynamics'' was first proposed by Alfven in 1941. 7 Magneto-hydrodynamics has been and is still used in many fields including astrophysics, 8,9 MHD generators and pumps, 10,11 metallurgy, 12,13 fusion reactors, 14,15 nanotechnologies, 16,17 flow control, 18,19 and aerospace 20 and marine 21,22 propulsion systems. In the field of marine propulsion, perhaps one of the first related patents and manuscripts dates back to 1960s.…”

Section: Introductionmentioning

confidence: 99%

Taguchi parametric analysis of the effects of electrode and magnetic actuator characteristics on Lorentz forces and heat transfer of a weak low-profile magneto-hydrodynamic blanket propulsion system

Chekab

Ghadimi

2016

Proceedings of the Institution of Mechanical Engineers, Part C:

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Parametric studies are conducted on different aspects of a planar MHD propulsion system called propulsive MHD blanket. Effects of nine different parameters on the electro-magnetic thrust, efficiency, and heat transfer of the blanket are investigated. To efficiently conduct the parametric analysis, the Taguchi test design method is used and 16 cases are defined. The Ansys-CFX commercial code is utilized as numerical solver and the obtained results are validated using the Hartman problem which indicated a negligible error of 0.16%. Electromagnetism, energy, mass, and momentum equations are considered for the fluid domain and heat transfer and electromagnetism equations are solved for the solid domain. On one hand, magnet shapes and type are found to be the highest effective parameters, followed by the electrodes voltage, length, and width. On the other hand, a prediction of the best combination of parameters for obtaining the highest electro-magnetic thrust are statistically accomplished which has produced an electro-magnetic thrust of 18.02 N per square meter for the MHD blanket which is twice the maximum electro-magnetic thrust obtained in the 16 initial test cases. It is demonstrated in the present paper that the unique applications of propulsive MHD blanket can compensate the very low efficiencies of MHD systems. It has also been shown that efficiency can be improved by enhancing the water conductivity, which is intended as a future study.

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Magnetohydrodynamic boundary layer control with suction or injection

Cited by 17 publications

References 7 publications

On the similarity solutions for a steady MHD equation

On the similarity solutions for a steady MHD equation

Preliminary Experimental Investigation on a Low Profile Magneto-Hydrodynamic Propulsive Blanket, Considering Plasma Generation

Taguchi parametric analysis of the effects of electrode and magnetic actuator characteristics on Lorentz forces and heat transfer of a weak low-profile magneto-hydrodynamic blanket propulsion system

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