Turbulent friction and heat transfer behaviors of dispersed fluids (i.e., uttrafine metallic oxide particles suspended in water) in a circular pipe were investigated experimentally. Viscosity measurements were also conducted using a Brookfield rotating viscometer. Two different metallic oxide particles, γ-alumina (Al2O3) and titanium dioxide (TiO2), with mean diameters of 13 and 27 nm, respectively, were used as suspended particles. The Reynolds and Prandtl numbers varied in the ranges l04-I05 and 6.5-12.3, respectively. The viscosities of the dispersed fluids with γ-Al2O3 and TiO2 particles at a 10% volume concentration were approximately 200 and 3 times greater than that of water, respectively. These viscosity results were significantly larger than the predictions from the classical theory of suspension rheology. Darcy friction factors for the dispersed fluids of the volume concentration ranging from 1% to 3% coincided well with Kays' correlation for turbulent flow of a single-phase fluid. The Nusselt n...

Hydrodynamic and heat transfer study of dispersed fluids with submicron metallic oxide particles

http://wrap.warwick.ac.uk/44841/1/WRAP_Tian_Review%20on%20thermal%20energy%20storage%20with%20phase%20change.pdf

Review on thermal energy storage with phase change materials (PCMs) in building applications

Review on phase change materials (PCMs) for cold thermal energy storage applications

Paraffin/porous-graphite-matrix composite as a high and constant power thermal storage material

Energy storage components improve the energy efficiency of systems by reducing the mismatch between supply and demand. For this purpose, phase-change materials are particularly attractive since they provide a high-energy storage density at a constant temperature which corresponds to the phase transition temperature of the material. Nevertheless, the incorporation of phase-change materials (PCMs) in a particular application calls for an analysis that will enable the researcher to optimize performances of systems. Due to the non-linear nature of the problem, numerical analysis is generally required to obtain appropriate solutions for the thermal behavior of systems. Therefore, a large amount of research has been carried out on PCMs behavior predictions. The review will present models based on the first law and on the second law of thermodynamics. It shows selected results for several configurations, from numerous authors so as to enable one to start his/her research with an exhaustive overview of the subject. This overview stresses the need to match experimental investigations with recent numerical analyses since in recent years, models mostly rely on other models in their validation stages.

A review on phase-change materials: Mathematical modeling and simulations

Forced convection heat transfer in microencapsulated phase change material slurries: flow in circular ducts

https://deepblue.lib.umich.edu/bitstream/handle/2027.42/31756/0000697.pdf;sequence=1

Laminar forced convection heat transfer in microcapsulated phase change material suspensions

Conclusions Expressions for the analytical temperature distribution and ef ciency of a heat pipe  n were derived and compared with experimental data. Two heat pipe  n cases were studied,  ush mounted and inserted into the object. The derived expressions are useful as a design tool. They allow the designer to compare heat pipe  ns to standard  ns before doing a detailed heat pipe design. Further researchcould focus on variations in heat pipe design and geometry.Thesecouldincludenonconstantpropertiesandboundary conditions.For this work, the wall cross-sectionalarea, the internal convectioncoef cient, and the external convectioncoef cient were assumed constant. The impact of these assumptions on accuracy should be investigated. It would also be interesting to extend the analysis to  ns in radiation environments.

Sanjay K. Roy

Papers

Forced convection heat transfer in microencapsulated phase change material slurries: flow in circular ducts

Laminar forced convection heat transfer in microcapsulated phase change material suspensions

Forced Convection Heat Transfer to Phase Change Material Slurries in Circular Ducts

Laminar forced convection heat transfer with phase change material suspensions

An evaluation of phase change microcapsules for use in enhanced heat transfer fluids