This article explores the optimization of heat transport in a magnetohydrodynamic nanofluid flow with mixedMarangoni convection by using the Response SurfaceMethodology.The convective flow is studied with external mag...This article explores the optimization of heat transport in a magnetohydrodynamic nanofluid flow with mixedMarangoni convection by using the Response SurfaceMethodology.The convective flow is studied with external magnetism,radiative heat flux,and buoyancy.An internal heat absorption through the permeable surface is also taken into account.The governing system includes the continuity equation,Navier-Stokes momentum equation,and the conservation of energy equations,approximated by the Prandtl boundary layer theory.The entropy generation in the thermodynamic system is evaluated.Experimental data(Corcione models)is used to model the single-phase aluminawater nanofluid.The numerical solution for the highly nonlinear differential systemis obtained via Ralston’s algorithm.It is observed that the applied magnetic field leads to a higher entropy generation which is engendered by the Lorentz force within the fluid system.The thermal radiation leads to a higher Bejan number,indicating the importance of the irreversibility of heat transport.Also,the heat absorption process via a permeable surface can be employed to regulate the thermal field.An optimizedNusselt number of 13.4 is obtained at the high levels of radiation,injection,and heat sink parameters.The modeled fluid flow scenario is often seen in drying,coating,and heat exchange processes,especially in microgravity environments.展开更多
In gas-liquid mass transfer processes,Marangoni convection may occur due to the surface tension gradient produced by mass transfer near the interface.With a falling soap film tunnel and the Schlieren optical method,th...In gas-liquid mass transfer processes,Marangoni convection may occur due to the surface tension gradient produced by mass transfer near the interface.With a falling soap film tunnel and the Schlieren optical method,the Marangoni convection patterns along the film surface were observed directly in the desorption process of acetone from the falling soap film.The Schlieren images showed the regular roll convection in the thin falling soap film during the acetone desorption.The hydraulic characteristics were determined experimentally by measuring the variation of acetone concentration in the film and the surface tension of the soap liquid.The results show that the acetone concentration gradient vertical to the falling direction is very small because the thickness of the soap film is in the order of 10-6 m.The variation of acetone concentration along the falling film is large,so there is a significant surface tension gradient,resulting in the Marangoni roll convection.The experimental results and a qualitative analysis may be helpful to understand the mechanism of Marangoni convection near the interface in the mass transfer.展开更多
文摘This article explores the optimization of heat transport in a magnetohydrodynamic nanofluid flow with mixedMarangoni convection by using the Response SurfaceMethodology.The convective flow is studied with external magnetism,radiative heat flux,and buoyancy.An internal heat absorption through the permeable surface is also taken into account.The governing system includes the continuity equation,Navier-Stokes momentum equation,and the conservation of energy equations,approximated by the Prandtl boundary layer theory.The entropy generation in the thermodynamic system is evaluated.Experimental data(Corcione models)is used to model the single-phase aluminawater nanofluid.The numerical solution for the highly nonlinear differential systemis obtained via Ralston’s algorithm.It is observed that the applied magnetic field leads to a higher entropy generation which is engendered by the Lorentz force within the fluid system.The thermal radiation leads to a higher Bejan number,indicating the importance of the irreversibility of heat transport.Also,the heat absorption process via a permeable surface can be employed to regulate the thermal field.An optimizedNusselt number of 13.4 is obtained at the high levels of radiation,injection,and heat sink parameters.The modeled fluid flow scenario is often seen in drying,coating,and heat exchange processes,especially in microgravity environments.
文摘In gas-liquid mass transfer processes,Marangoni convection may occur due to the surface tension gradient produced by mass transfer near the interface.With a falling soap film tunnel and the Schlieren optical method,the Marangoni convection patterns along the film surface were observed directly in the desorption process of acetone from the falling soap film.The Schlieren images showed the regular roll convection in the thin falling soap film during the acetone desorption.The hydraulic characteristics were determined experimentally by measuring the variation of acetone concentration in the film and the surface tension of the soap liquid.The results show that the acetone concentration gradient vertical to the falling direction is very small because the thickness of the soap film is in the order of 10-6 m.The variation of acetone concentration along the falling film is large,so there is a significant surface tension gradient,resulting in the Marangoni roll convection.The experimental results and a qualitative analysis may be helpful to understand the mechanism of Marangoni convection near the interface in the mass transfer.
