The Experts below are selected from a list of 100143 Experts worldwide ranked by ideXlab platform
Mathew Kinyanjui - One of the best experts on this subject based on the ideXlab platform.
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Hydromagnetic free convection currents effects on boundary layer thickness
Energy Conversion and Management, 2010Co-Authors: J.k. Kwanza, E.m. Marigi, Mathew KinyanjuiAbstract:Abstract In this study we discuss an unsteady free convection MHD flow past semi-infinite vertical porous plate. We have considered the flow in the presence of a strong magnetic field and therefore the electromagnetic force is very large. This brings in the phenomenon of Hall and Ion-slip currents. The effects of these two parameters together with that of viscous dissipation and Radiation Absorption among others on velocity, temperature and concentration profiles are presented. The profiles are presented graphically. As the partial differential equations governing this problem are highly non-linear they are solved numerically by a finite difference method. It is found that in presence of heating of the plate by free convection current the velocity boundary layer thickness decreases.
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magnetohydrodynamic free convection heat and mass transfer of a heat generating fluid past an impulsively started infinite vertical porous plate with hall current and Radiation Absorption
Energy Conversion and Management, 2001Co-Authors: Mathew Kinyanjui, J.k. Kwanza, S M UppalAbstract:Simultaneous heat and mass transfer in unsteady free convection flow with Radiation Absorption past an impulsively started infinite vertical porous plate subjected to a strong magnetic field is presented. The governing equations for the problem are solved by a finite difference scheme. The influence of the various parameters on the convectively cooled or convectively heated plate in the laminar boundary layer are considered. An analysis of the effects of the parameters on the concentration, velocity and temperature profiles, as well as skin friction and the rates of mass and heat transfer, is done with the aid of graphs and tables.
S. Venkataramana - One of the best experts on this subject based on the ideXlab platform.
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Radiation Absorption effect on MHD, free convection, chemically reacting visco-elastic fluid past an oscillatory vertical porous plate in slip flow regime
2014Co-Authors: M C Raju, B. Vidyasagar, S. VenkataramanaAbstract:In this paper an analysis presented to investigate the influence of Radiation Absorption, chemical reaction and heat source effects on hydro magnetic free convection heat and mass transfer flow of visco-elastic fluid through porous medium bounded by an oscillating porous plate in the slip flow regime with constant suction and temperature dependent heat source. A uniform magnetic field of strength B0 is applied at an angle α with the field flow direction. Analytical solutions for velocity, temperature and concentration are obtained. Skin friction, rate of heat and mass transfer coefficients are also derived. The results have been analyzed and presented graphically for various values of the flow parameters. It is observed that velocity increases with an increase in porosity parameter, Radiation Absorption, Grashof number, modified Grashof number and it decreases with an increase in magnetic parameter, Schmidt number, chemical reaction parameter, Prandtl number.
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unsteady mhd free convection boundary layer flow of Radiation absorbing kuvshinski fluid through porous medium
Advances in Physics Theories and Applications, 2014Co-Authors: M C Raju, Vidya B Sagar, S V K Varma, S. VenkataramanaAbstract:An analytical study is carried out for an unsteady MHD two dimensional free convection flow of a viscous, incompressible, radiating, chemically reacting and Radiation absorbing Kuvshinski fluid through a porous medium past a semi-infinite vertical plate. The dimensionless equations governing the flow are solved by simple perturbation technique. The expressions for velocity, temperature and concentration are derived. The influence of various material parameters on flow quantities are studied and discussed with the help of graphs. The expressions for Skin friction, Nusselt number and Sherwood number are also derived and discussed numerically. Temperature increases with an increase in Radiation parameter and Radiation Absorption parameter where as it decreases with an increase in Prandtl number. Concentration is observed to be decreased when chemical reaction parameter and Schmidt number increase.
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effects of hall current and Radiation Absorption on mhd micropolar fluid in a rotating system
Ain Shams Engineering Journal, 2013Co-Authors: P Satya V Narayana, B Venkateswarlu, S. VenkataramanaAbstract:Abstract The objective of this paper is to study the effects of Hall current and Radiation Absorption on MHD free convection mass transfer flow of a micropolar fluid in a rotating frame of reference. A uniform magnetic field acts perpendicular to the porous surface in which absorbs micropolar fluid with a constant suction velocity. The entire system rotates about the axes normal to the plate with uniform angular velocity Ω . The dimensionless governing equations for this investigation are reduced to a system of linear differential equations using regular perturbation method, and equations are solved analytically. The influence of various flow parameters of the flow field has been discussed and explained graphically. The present study is of immediate interest in geophysical, cosmically fluid dynamics, medicine, biology, and all those processes which are greatly embellished by a strong magnetic field with a low density of the gas.
Zheng Chen - One of the best experts on this subject based on the ideXlab platform.
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effects of Radiation Absorption on spherical flame propagation and Radiation induced uncertainty in laminar flame speed measurement
Proceedings of the Combustion Institute, 2017Co-Authors: Zheng ChenAbstract:Abstract Outwardly propagating spherical flames are popularly used to measure the laminar flame speed, especially for high pressure conditions. Since Radiation always exists in spherical flame experiments, the accuracy of laminar flame speed measurement is inherently affected by Radiation. In this study, the Radiation-induced uncertainty in laminar flame speed measurement was investigated numerically. We focused on CO 2 diluted mixtures in which the Radiation Absorption effects are important. The outwardly propagating spherical flames of different CO 2 diluted mixtures at a broad range of pressure up to 25 atm were simulated. Different fuels (hydrogen, methane, dimethyl ether and iso-octane) with different amounts of CO 2 dilution were considered and detailed chemistry was included in simulation. Two Radiation models were used: one is the optically thin model considering only Radiation emission and the other is the statistical narrow band model considering both Radiation emission and Absorption. The effects of Radiation Absorption on spherical flame propagation and Radiation-induced uncertainty in laminar flame speed measurement were quantified through comparison among results predicted by these two Radiation models. It was found that for CO 2 diluted mixtures, Radiation Absorption has great impact on spherical flame propagation: it greatly reduces the Radiation-induced thermal and flow effects. The influence of Radiation Absorption was show to be stronger at higher pressure. When only Radiation emission is considered and Radiation Absorption is neglected, the Radiation-induced uncertainty in laminar flame speed measurement is substantially over-predicted for CO 2 diluted mixtures. When Radiation Absorption is included, the Radiation-induced uncertainty in laminar flame speed measurement is nearly negligible (within 2.5%) for all the CO 2 diluted mixtures considered in this study.
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studies of Radiation Absorption on flame speed and flammability limit of co2 diluted methane flames at elevated pressures
Proceedings of the Combustion Institute, 2007Co-Authors: Zheng Chen, Xiao Qin, Fengshan LiuAbstract:Abstract The effects of spectral Radiation Absorption on the flame speed at normal and elevated pressures were experimentally and numerically investigated using the CO 2 diluted outwardly propagating CH 4 –O 2 –He flames. Experimentally, the laminar burning velocities of CH 4 –O 2 –He–CO 2 mixtures at both normal and elevated pressures (up to 5 atm) were measured by using a pressure-release type spherical bomb. The results showed that Radiation Absorption with CO 2 addition increases the flame speed and extends the flammability limit. In addition, it was also shown that the increase of pressure augments the effect of Radiation Absorption. Computationally, a fitted statistical narrow-band correlated- k (FSNB-CK) model was developed and validated for accurate Radiation prediction in spherical geometry. This new Radiation scheme was integrated to the compressible flow solver developed to simulate outwardly propagating spherical flames. The comparison between experiment and computation showed a very good agreement. The results showed that the flame geometry have a significant impact on Radiation Absorption and that the one-dimensional planar Radiation model was not valid for the computation of the flame speed of a spherical flame. An effective Boltzmann number is extracted from numerical simulation. Furthermore, the FSNB-CK model was compared with the grey band SNB model. It was shown that the grey band SNB model over-predicts the Radiation Absorption. It is concluded that quantitative prediction of flame speed and flammability limit of CO 2 diluted flame requires accurate spectral dependent Radiation model.
J.k. Kwanza - One of the best experts on this subject based on the ideXlab platform.
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Hydromagnetic free convection currents effects on boundary layer thickness
Energy Conversion and Management, 2010Co-Authors: J.k. Kwanza, E.m. Marigi, Mathew KinyanjuiAbstract:Abstract In this study we discuss an unsteady free convection MHD flow past semi-infinite vertical porous plate. We have considered the flow in the presence of a strong magnetic field and therefore the electromagnetic force is very large. This brings in the phenomenon of Hall and Ion-slip currents. The effects of these two parameters together with that of viscous dissipation and Radiation Absorption among others on velocity, temperature and concentration profiles are presented. The profiles are presented graphically. As the partial differential equations governing this problem are highly non-linear they are solved numerically by a finite difference method. It is found that in presence of heating of the plate by free convection current the velocity boundary layer thickness decreases.
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magnetohydrodynamic free convection heat and mass transfer of a heat generating fluid past an impulsively started infinite vertical porous plate with hall current and Radiation Absorption
Energy Conversion and Management, 2001Co-Authors: Mathew Kinyanjui, J.k. Kwanza, S M UppalAbstract:Simultaneous heat and mass transfer in unsteady free convection flow with Radiation Absorption past an impulsively started infinite vertical porous plate subjected to a strong magnetic field is presented. The governing equations for the problem are solved by a finite difference scheme. The influence of the various parameters on the convectively cooled or convectively heated plate in the laminar boundary layer are considered. An analysis of the effects of the parameters on the concentration, velocity and temperature profiles, as well as skin friction and the rates of mass and heat transfer, is done with the aid of graphs and tables.
N Ranganath - One of the best experts on this subject based on the ideXlab platform.
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Radiation dissipation and dufour effects on mhd free convection flow through a vertical oscillatory porous plate with ion slip current
International Journal of Heat and Technology, 2018Co-Authors: K V B Rajakumar, Ch Ramana V Murthy, K S Balamurugan, N RanganathAbstract:In this paper, the Dufour, Radiation Absorption, chemical reaction, and viscous dissipation effects on unsteady magneto hydrodynamic free convective flow through a semi-infinite vertical oscillatory porous plate of time-dependent permeability with Hall and ion slip current in a rotating system were investigated. The governing equations of the problem are solved by using Multiple Regular Perturbation law. The possessions of various parameters on velocity, temperature, and concentration are shown graphically.
