Latent heat

About: Latent heat is a research topic. Over the lifetime, 13503 publications have been published within this topic receiving 302811 citations.

Improved performance of latent heat energy storage systems utilizing high thermal conductivity fins: A review

Abstract: A review of the analytical, computational, and experimental studies directed at improving the performance of phase change material-based (PCM) latent heat energy storage systems that utilize high thermal conductivity fins is presented. Spanning over many decades, managing of heat generation associated with electronics utilized for early work on aeronautics and space exploration was emphasized, with later extensions to waste heat recovery, passive thermal management of computing platforms, and energy storage for solar thermal applications. The focus of this review is placed on investigations that deal with utilization of non-moving fins/extended surfaces with high conductivity. Aluminum, brass, bronze, copper, iron, mild steel, nickel, and stainless steel were the metal-based fin materials of choice utilized to promote heat transfer, whereas carbon fiber brushes were also used. A variety of phase change materials including pure/commercial paraffins, carbonate mixtures, polyethylene glycol, chloride mixture...

Studies of moisture effects in simple atmospheric models: The stable case

Abstract: The shallow-water equations are supplemented by a moisture equation in order to model effects of latent heat release on the horizontal propagation of disturbances. Since latent heating in regions of upward motion compensates the reduction in perturbation temperature due to lifting, buoyancy effects are reduced and disturbances propagate more slowly. Analytic solutions are obtained to illustrate this effect, a good example being provided by the collapse of an initial horizontal temperature discontinuity. Another interesting example is provided by the case of disturbances propagating through a region from one side. Moist regions are found to have front and rear boundaries which both move faster than rainbands do inside the moist region. If random disturbances are passed through a region which is initially saturated, the relative humidity drops until it reaches a value which depends on the disturbance level.

The surface energy balance of a polygonal tundra site in northern Siberia – Part 1: Spring to fall

Abstract: . In this article, we present a study on the surface energy balance of a polygonal tundra landscape in northeast Siberia. The study was performed during half-year periods from April to September in each of 2007 and 2008. The surface energy balance is obtained from independent measurements of the net radiation, the turbulent heat fluxes, and the ground heat flux at several sites. Short-wave radiation is the dominant factor controlling the magnitude of all the other components of the surface energy balance during the entire observation period. About 50% of the available net radiation is consumed by the latent heat flux, while the sensible and the ground heat flux are each around 20 to 30%. The ground heat flux is mainly consumed by active layer thawing. About 60% of the energy storage in the ground is attributed to the phase change of soil water. The remainder is used for soil warming down to a depth of 15 m. In particular, the controlling factors for the surface energy partitioning are snow cover, cloud cover, and the temperature gradient in the soil. The thin snow cover melts within a few days, during which the equivalent of about 20% of the snow-water evaporates or sublimates. Surface temperature differences of the heterogeneous landscape indicate spatial variabilities of sensible and latent heat fluxes, which are verified by measurements. However, spatial differences in the partitioning between sensible and latent heat flux are only measured during conditions of high radiative forcing, which only occur occasionally.