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This is accomplished by solving heat equations in both regions, subject to given boundary and initial conditions. At the interface between the phases (in the classical problem) the temperature is set to the phase change temperature. To close the mathematical system a further equation, the Stefan condition, is required. This is an energy balance ...
The systems are developed in such manner that phase change materials are in the shell portion of the module and passage for the flow of air through the tubes. Conjugate steady state CFD heat transfer analysis has been carried out [6] to analyze the flow and temperature variation of heat transfer fluid in the system.
The number of transfer units (NTU) method is used to calculate the rate of heat transfer in heat exchangers (especially parallel flow, counter current, and cross-flow exchangers) when there is insufficient information to calculate the log mean temperature difference (LMTD). Alternatively, this method is useful for determining the expected heat ...
However, if the specific heat changes, the LMTD approach will no longer be accurate. A particular case for the LMTD are condensers and reboilers, where the latent heat associated to phase change is a special case of the hypothesis. For a condenser, the hot fluid inlet temperature is then equivalent to the hot fluid exit temperature.
The Fay-Riddell equation is a fundamental relation in the fields of aerospace engineering and hypersonic flow, which provides a method to estimate the stagnation point heat transfer rate on a blunt body moving at hypersonic speeds in dissociated air. [1] The heat flux for a spherical nose is computed according to quantities at the wall and the ...
Phase transition or phase change, takes place in a thermodynamic system from one phase or state of matter to another one by heat transfer. Phase change examples are the melting of ice or the boiling of water. The Mason equation explains the growth of a water droplet based on the effects of heat transport on evaporation and condensation.
The study of heat transfer in micro-encapsulated phase-change slurries is an application where the Biot number is useful. For the dispersed phase of the micro-encapsulated phase-change slurry, the micro-encapsulated phase-change material itself, the Biot number is calculated to be below 0.1 and so it can be assumed that thermal gradients within ...
One of the key parameter which characterizes the gas flow over the droplet is the droplet Reynolds number based on the relative velocity, droplet diameter and gas phase properties. The features of the gas flow have a critical impact on the exchanges of mass, momentum and energy between the gas and the liquid phases and thus, they have to be ...