Latest Research News on Convection Flow Research: Oct – 2019

The incipience of nucleate boiling in forced convection flow

An analysis of the get-go of nucleate boiling is developed as a modification and extension of previous analyses. The results area unit compared with knowledge for subcooled boiling of water in forced convection flow. Apparent anomalies within the knowledge for the onset of boiling in two‐phase gas‐liquid flow area unit shown to be a results of a restricted size vary of cavities on the heater surfaces. Measurements of the surface characteristics of a copper heating tube were created and compared with early boiling heat transfer knowledge taken therein tube. The results expected from the theoretical analysis area unit in line with the experimental heat transfer knowledge. [1]

Longitudinal vortices in natural convection flow on inclined plates

Experiments are performed to demonstrate the prevalence ANd explore the characteristics of a secondary flow superposed upon the natural convection main flow on an inclined plate. A flow visual image technique is utilized whereby the flow pattern is formed visible by native changes of color of the fluid itself, the color modification being led to by a change in pH scale. The secondary flow consists of longitudinal vortices or rolls distributed a lot of or less sporadically across the dimension of the plate. the amount of such vortices will increase with the temperature distinction between the surface and also the close fluid, however seems to be comparatively insensitive to the inclination angle of the plate. The secondary flow results from the destabilizing impact of the buoyancy force element, that acts traditional to the plate surface. The longitudinal vortices are the primary stage of the laminarturbulent transition method. this can be in distinction to the case of natural convection on a vertical plate, wherever the primary stage of transition is Tollmien-Schlichting waves. [2]

Free convection flow of non-Newtonian fluids along a vertical plate embedded in a porous medium

The problem of free convection flow of a non-Newtonian Stevens’ law fluid on associate equal vertical flat plate embedded within the porous medium is taken into account within the gift study. The physical frame of reference is shown schematically in Fig one. within the gift study, it’s assumed that the changed Darcy law and also the physical phenomenon approximation square measure applicable. this means that the current solutions square measure valid at a high John William Strutt range. With these simplifications, the governing partial nonlinear differential equations may be reworked into a group of coupled normal differential equations which might be solved  by the fourth-order Runge-Kutta technique. pure mathematics equations for warmth transfer rate and physical phenomenon thickness as a perform of the prescribed wall temperature and physical properties of liquid-porous medium square measure obtained. The similarity solutions may be applied to issues in geophysical science and engineering. the first purpose of the current study is to predict the characteristics of steady natural convection heat transfer mistreatment the model of the flow of a non-Newtonian Stevens’ law fluid in a very porous medium given by Dharmadhikari and Kale (1985). Secondly, the consequences of the new Stevens’ law index n on heat transfer square measure investigated. [3]

Microparticles controllable accumulation, arrangement, and spatial shaping performed by tapered-fiber-based laser-induced convection flow

The ability to rearrange cells and/or microparticles into the specified pattern is vital in biological, chemical, and metamaterial studies and alternative applications. Researchers have developed a range of patterning techniques, that either have a restricted capability to at the same time entice large particles or lack the spacial resolution necessary to control individual particle. many approaches are projected that mix each high spacial property and high output at the same time. However, those strategies are advanced and tough to fabricate. during this article, we tend to propose and demonstrate a straightforward methodology that mixes the laser-induced convection flow and fiber-based optical housing strategies to perform each regular and special spacial shaping arrangement. primarily, we tend to mix a light-weight field with an outsized optical intensity gradient distribution and a thermal field with a large gradient distribution to perform the microparticles shaping arrangement. [4]

MHD and Slip Boundary Condition Effects on Forced Convection Flow through a Microchannel Including Viscous Dissipation

This study analyzes laminal forced convection flow in parallel plate micro-channel with slip rate and temperature jump within the presence of transversal magnetic flux. Closed-form solutions are obtained for rate and thermal profiles once each walls of the channel are unbroken at unequal temperatures. the results of assorted dominant parameters like  Hartman variety, concentration parameter, fluid-wall interaction parameter and Brinkman variety on the thermal behavior are mentioned with the help of line graphs. fascinating result from the current work is that increase in concentration parameter results in improvement in fluid temperature whereas increase in fluid-wall interaction parameter leads to increase in temperature move the walls of the channel. [5]

Reference

[1] Davis, E.J. and Anderson, G.H., 1966. The incipience of nucleate boiling in forced convection flow. AIChE Journal, 12(4), (Web Link)

[2] Sparrow, E.M. and Husar, R.B., 1969. Longitudinal vortices in natural convection flow on inclined plates. Journal of Fluid Mechanics, 37(2), (Web Link)

[3] Chen, H.T., 1988. Free convection flow of non-Newtonian fluids along a vertical plate embedded in a porous medium. Journal of Heat Transfer (Transactions of the ASME (American Society of Mechanical Engineers), Series C);(United States), 110(1). (Web Link)

[4] Microparticles controllable accumulation, arrangement, and spatial shaping performed by tapered-fiber-based laser-induced convection flow
Yu Zhang, Jiaojie Lei, Yaxun Zhang, Zhihai Liu, Jianzhong Zhang, Xinghua Yang, Jun Yang & Libo Yuan
Scientific Reports volume 7, Article number: 14378 (2017) (Web Link)

[5] Anyanwu, E. O., James, F. E., Ogwumu, O. D., Ogbaji, E. O. and Okorie, C. E. (2018) “MHD and Slip Boundary Condition Effects on Forced Convection Flow through a Microchannel Including Viscous Dissipation”, Asian Research Journal of Mathematics, 11(1), (Web Link)