A Robust Threshold Method of Mixed Layer Height Based on Lidar Turbulence Data Under Different Thermal Convection Conditions

Energy-conserving dissipative particle dynamics simulation of macromolecular solution flow in micro-channel under thermal convection

Quantitative microsegregation analysis was carried out on Sb‐doped silicon crystal pulled from the melt. Interference by thermal convection in the melt, invariably present in silicon growth at commonly used rates of pulling and seed rotation, was eliminated by introducing severe thermal asymmetry in the growth system. Interface demarcation was employed for the determination of the microscopic growth rates and spreading resistance measurements for obtaining composition profiles. For growth under forced convection conditions it was shown that the microsegregation behavior is controlled by the microscopic growth rate and is adequately accounted for by the Burton, Prim, and Slichter (BPS) model based on steady‐state segregation. The small deviations from steady‐state segregation were manifested as solute redistribution transients associated with the periodic growth rate variations (slight phase shift between dopant concentration and microscopic growth rate). For growth under thermal convection conditions, the microscopic growth rate is modulated by convective temperature fluctuations in the melt, but it does not control the microsegregation behavior because under these conditions the diffusion boundary layer thickness undergoes significant fluctuations. Accordingly, the BPS model, which assumes a constant diffusion boundary layer thickness, was found to be inapplicable to microsegregation in silicon grown under thermal convection.

Corrosion characteristics of low activation ferritic steel, JLF-1, in liquid lithium in static and thermal convection conditions

A theoretical study on the effect of magnetohydrodynamic field on the classical Blasius and Sakiadis flows of heat transfer characteristics with variable conditions and variable properties are studied in this paper. Hydromagnetic flows and heat transfer in porous media have been considered extensively in recent years due to their occurrence in several engineering processes such as compact heat exchangers, metallurgy, casting, filtration of liquid metals, cooling of nuclear reactors and fusion control. The governing partial differential equations are converted into ordinary differential equations using the suitable similarity transformations. The transformed boundary layer equations like momentum and energy equations are solved numerically by using Runge–Kutta method. The effect of governing physical parameters over the velocity and temperature distributions is demonstrated graphically. Moreover, the local friction factor coefficient and rate of heat transfer in terms of Nusselt number are computed and discussed through tables. We validated the present solutions with already existing studies under limited cases. It is found that the thermal buoyancy parameter enhances the velocity depreciates the temperature field for both the Sakiadis and Blasius flow cases. The influence of Biot number increases skin friction coefficient and local Nusselt number for both Sakiadis and Blasius flow cases.The rate of heat transfer for temperature ratio parameter is high in Blasius flow case when compared with Sakiadis flow case.

The study of advanced nanofluids termed as Tetra nanofluid is of potential interest now a days. These fluids are upgraded generation of conventional nano to ternary hybrid nanofluids with outstanding characteristics. Applications of this class frequently occur in applied thermal engineering, nano‐lubrication, chemo‐therapy, chemical engineering, oil paint industry, coolant of nuclear plant and many other applied research areas. This study concerns with the development of innovative thermophysical rules for Tetra Hybrid nanofluid and their utilization in advanced heat transfer model. The governing laws updated through addition of thermal condition, dissipation effects, thermal radiations and upgraded nanofluid properties. Finally, the Blasius and Sakiadis model achieved and analyzed the heat transfer trends through numerical technique. Keen analysis of the drawn results show that Blasius model has much ability to transfer the heat than Sakiadis model. Induction of thermal radiations, dissipation effects and thermal convective condition is like a catalysis in the study of advanced tetra nanofluid model and boosts the temperature.

A revised model for Darcy-Forchheimer three-dimensional flow of nanofluid subject to convective boundary condition

Significance of melting process in magnetized transport of hybrid nanofluids: A three-dimensional model

Two major contributors to the overall seeing that degrades astronomical images are turbulence from the atmosphere and turbulence within the telescope dome structure. Dome seeing generally contributes less than 1 arcsec to the overall seeing. However, most existing telescope domes have not been characterized for dome seeing; there is an opportunity to significantly improve the overall seeing by optimizing the dome seeing. An instrument that measures a proxy to dome seeing was installed at the Anglo-Australian Telescope (AAT) at Siding Spring Observatory in Australia. The instrument is based on a similar ’dome seeing monitor’ built and tested by Bustos and Tokovinin for the 4 m Blanco telescope in 2018. The instrument consists of a collimated laser beam that propagates from the AAT’s primary mirror box, reflects off a flat mirror on the secondary strut, back down to the primary mirror box, and is imaged by a camera. The angle-of-arrival fluctuations are used to derive the seeing proxy in arcsec. Meteorology is recorded in parallel to the dome seeing proxy, including inside, outside, and mirror temperature, humidity, pressure, wind speed and direction, and telescope azimuth and elevation. These meteorology variables were tested for correlation to the dome seeing proxy. There are 77 nights worth of data, spanning from August 2021 to May 2022. The highly correlated variables were the outdoor/indoor and indoor/mirror temperature difference, the wind speed and humidity. Poorly correlated variables include the wind-to-dome slit angle, the sky/ambient temperature difference and elevation. Thermal convection conditions were found to significantly affect the dome-seeing-proxy compared to thermal inversion conditions.

Adding variety of nanoparticles to the base fluid is current technique in order to boost the thermal performance of conventional fluids and mononanofluids. The forthright intention of the present investigation is to analyze numerically the up-to-date progress in flow and heat transport nature of magnetohydrodynamic, radiative Newtonian fluid, water-based Al2O3 nanofluid, water-based graphene nanofluid and water based Al2O3 + graphene hybrid nanofluid due to convectively heated stretching sheet. The flow equations are transformed by applying appropriate transformations into a pair of self-similarity equations. Further similarity equivalences are numerically solved through Runge–Kutta based shooting method. Graphs and tables are structured to analyze the behavior of sundry influential variables. From this study it is found that rate of heat transfer for Graphene + water is 2.921934, Al2O3 + H2O + Graphene is 2.250658 and Al2O3 + H2O is 3.260554. From this we conclude that water based Al2O3 + graphene hybrid nanofluid can be opted for cooling performance. Water based Al2O3 nanofluid significantly enhance convection heat transfer performance over a stretching sheet. Friction at the wall for Graphene + water is (− 1.719525), Al2O3 + H2O + Graphene is (− 2.256614) and Al2O3 + H2O is (− 1.959539). From this we conclude that water based Al2O3 + graphene hybrid nanofluid shows lower wall friction rate compared to other two mixture compositions.

Heat and mass transmission through the nanofluids flow subject to exponential heat source/sink and thermal convective condition across Riga plates

This article conveys a comparative analysis of the magnetohydrodynamic flow of water-based and kerosene oil-based copper and copper oxide hybrid nanofluids flow past a bi-directional stretching surface. The Maxwell model is considered in order to analyze the non-Newtonian behaviour of the hybrid nanofluids flow. The slip conditions are also visualised to analyze and compare the behaviours of the hybrid nanofluids flow due to different embedded parameters. Suitable similarity transformations are used to transfer PDEs into ODEs. The renovated system of equations is solved with the help of HAM. The convergence of HAM is shown with the help of figure. The results showed that the flow behaviour is always dominant for the case of no-slip conditions as compared to slip conditions. For the case of no-slip conditions, no variation is found in the skin fraction coefficient of the water-based hybrid nanofluid flow and kerosene oil-based hybrid nanofluid flow containing copper and copper oxide nanoparticles along with both primary and secondary directions via magnetic parameter, suction/injection parameter, and Deborah number. The increasing nanoparticles volume fractions of copper and copper oxide, and thermal Biot number augment the heat transfer rate of the water-based and kerosene oil-based hybrid nanofluids flow containing copper and copper oxide nanoparticles, while reduces with the augmenting Deborah number due to heat. The greater stretching parameter heightens the velocity profiles along with primary and secondary directions, while the opposite impact is found via magnetic parameter. Comparing the cases of slip and no-slip conditions, the greater impact along primary and secondary directions is observed for no-slip condition.

Influence of chemical reaction and thermal convective condition on the heat and mass transport in boundary layer flow over a magneto-radiated wedge with cross diffusion

Theoretical study on thermal efficiencies of Sutterby ternary-hybrid nanofluids with surface catalyzed reactions over a bidirectional expanding surface

The present investigation computes the heat transport phenomenon of the magnetohydrodynamic (MHD) flow of CuO-Ag/H2O hybrid nanofluid over a spinning disc. The authors are confident that there is very less analysis covering the fluid flow containing silver and copper oxide nanoparticles over a rotating disk. Therefore, the authors are interested to consider the water-based nanoliquid flow over a spinning disk. Furthermore, the velocity slip and thermal convective conditions are taken into consideration. The formulation of the problem is made in the form of PDEs and is then converted into the nonlinear ODEs by employing suitable similarity transformations. The homotopic analysis approach is applied for the semi-analytical solution of these resulting equations. The convergence of homotopic approach has also revealed with the help of figure. The performance of the hybrid nanofluid flow velocities and temperature has been shown in a graphical form against distinct flow parameters. Also, the numerical results of skin friction coefficient and Nusselt number have been calculated in a tabular form. The outcomes of the current problem show that the increase in the skin friction of the water-based copper oxide nanofluid is greater than the water-based silver nanofluid at 4% of the nanoparticle volume fraction. Also, the skin friction of the hybrid nanofluid is increased by 8% compared to the silver nanofluid at 4% of the nanoparticle volume fraction. Furthermore, the heat transfer rate of the water-based copper oxide nanofluid is greater than the water-based silver nanofluid at 4% of the nanoparticle volume fraction. Also, the heat transfer rate of the hybrid nanofluid is 52% greater than that of silver nanofluid at 4% of the nanoparticle volume fraction. It is found that the Nusselt number of the hybrid nanofluid is highly affected by the embedded parameters as compared to nanofluids.

This study looks at how an electrically conducting Sutterby nanofluid flow due to a horizontal stationary sheet behaves under the influence of the Darcy–Forchheimer effect in a porous medium. Flows across a permeable medium possess interesting applications, including environmental and biological systems like soils, bones, and tissues. Heat and mass transmissions are enriched by viscous and ohmic dissipations, radiative heat flux, and chemical reaction. A thermal convective condition is imposed on the boundary of the surface. The governing fluid model of a nonlinear system is modeled using boundary layer approximations. Further, the transformed ordinary differential equations (ODEs) are obtained via a nonsimilarity procedure up to the second level of truncation and are numerically evaluated by using the bvp4c approach. The velocity, thermal, and concentration distributions are demonstrated graphically against the pertinent factors. Quantities of engineering, such as wall heat flux, wall drag coefficient, and surface mass flux, are tabulated numerically. The outcomes depict that the Eckert number diminishes the wall heat transmission rate while the wall mass transfer rate grows for the upsurging estimates of the chemical reaction parameter. Furthermore, the Lorentz force promotes wall heat transmission and lowers the mass transfer rate. The intended model is verified against the published work using a comparison table. An excellent correlation is noted between the values in percentage of the present and the published work, substantiating its truthfulness.