Topic
Stefan number
About: Stefan number is a research topic. Over the lifetime, 482 publications have been published within this topic receiving 32056 citations.
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01 Jan 2012
TL;DR: In this article, the authors report on the solid phase dy-namic response due to time-varying duct flows when a portion of a duct wall is cooled to below the liquidus temperature, along which unidirectional solidification from the cooling duct wall, perpendicular to the flow direction, is assumed.
Abstract: In the present study, we report on the solid phase dy- namic response due to time-varying duct flows when a portion of a duct wall is cooled to below the liquidus temperature, along which unidirectional solidification from the cooling duct wall, perpendicular to the flow direction, is assumed. A one-dimensional numerical model for the average solid phase thickness has been formulated employing the boundary tracking method. It is shown that a quasi-steady state temperature in the solid layer allows us to develop an analytical solution, making use of perturbation technique. The afore-mentioned perturbation analysis identifies important three nondimensional parameters, i.e. the Biot number based on the solid phase thickness at steady state, the Stefan number based on the temperature difference between the cooling wall and the liquidus temperatures, and the Stefan number based on the liquidus and the flowing liquid temperatures. Results ob- tained by both approaches agree well in general, and the time- variation trends of solid phase thickness and its phase delay have been obtained as a function of the non-dimensional angular fre- quency of the modulating duct flow velocity, with the above three non-dimensional parameters. Various applications in practical engineering and in engineering education have been identified and are being addressed by the developed Graphical Interface Frame- work for Educational and Engineering Support (GIFEES).
01 Jan 2021
TL;DR: In this article, the effect of helical fins on the total time required for melting and solidification of phase change material was determined, and the Reynolds and Stefan numbers were used as the performance parameters.
Abstract: The phase change materials are having capability to store the latent as well as the sensible form of heat. These materials are having poor rates of heat transfer during solid to liquid phase transformation and vice versa. It happens because of poor thermal conductivity of phase change materials. For improving rate of heat transfer, the fins with helical design are introduced in the phase change material. The paraffin wax was used as phase change material. Different experimentations were carried out by maintaining constant flow rate of heat transferring fluid and varying its inlet temperature. With the use of helical fins, the effect on the total time required for melting and solidification of phase change material was determined. The Reynolds and Stefan numbers are used as the performance parameters. This paper illustrates that the use of helical fins reduces the total cycle time of charging and discharging process of the phase change material compared with the plain latent heat storage system.
TL;DR: In this article, the authors proposed a semi-analytical model to calculate the total melting time of a slab based on a direct integration of the unsteady heat conduction equation, and provided quantitative results applicable to control the total melted time of the slab.
TL;DR: In this article, an analytical investigation of convection in a mushy layer that results due to the morphological instability of the interface during the solidification of a binary or a multicomponent alloy was carried out.
TL;DR: In this paper, a semi-analytical mathematical model was developed to describe the freezing, melting and dissolution processes of alumina particles and the time duration for each stage, based on the heat and mass transport mechanism of moisture containing porous media, with the conservation of thermal energy and mass.