Significant amounts of heat flow can be removed with small temperature differences by boiling. This process is used in a variety industries, e.g., cooling electronics, digital circuits, power sources, etc. Heat dissipation from equipment that generates significant flows involves the movement thermal energy through wall into fluid. In present study, this mechanism was analysed during boiling Nov...

The present study represents part of an effort in considering the replacement of ethylene-glycol/water mixtures with propyleneglycol/water mixtures for engine cooling in automotive application. Experimental results are presented for the heat transfer coeffic ient under flow boiling conditions for water and mixtures of water with ethylene-glycol and propylene-glycol. The range covered includes t...

Flow boiling in miniand microchannels offer very high heat transfer capabilities and find applications in many emerging technologies, such as electronics cooling and fuel cells. The low flow rate employed in such geometries, coupled with the small flow channels, often results in a laminar flow with all flow as liquid. Since the single-phase flow with all liquid is in the laminar range, the flow...

The evolution of fluid chemistry and mineral alteration around a potential waste emplacement tunnel (drift) is evaluated using numerical modeling. The model considers the flow of water, gas, and heat, plus reactions between minerals, CO(2) gas, and aqueous species, and porosity-permeability-capillary pressure coupling for a dual permeability (fractures and matrix) medium. Two possible operating...

Cavitation refers to the formation of bubbles in a liquid flow leading to a two-phase mixture of liquid and vapor/gas, when the local pressure drops below the vapor pressure of the fluid. Fundamentally, the liquid to vapor transition can occur by heating the fluid at a constant pressure, known as boiling, or by decreasing the pressure at a constant temperature, which is known as cavitation. Sin...

The calculation of two-phase flow boiling heat transfer of R22 in channels is required in a variety of applications, such as chemical process cooling systems, refrigeration, and air conditioning. A number of correlations for flow boiling heat transfer in channels have been proposed. This work evaluates the existing correlations for flow boiling heat transfer coefficient with 1669 experimental d...

Boiling conjugate heat transfer is an active field of research encountered in several industries, including metallurgy, power generation and electronics. This paper presents a computational fluid dynamics approach capable accurately modelling the flow phenomena during immersion quenching: process which hot solid immersed into liquid, leading to sudden boiling at solid–liquid interface. The adop...

Population balance equations combined with a threedimensional two-fluid model are employed to predict bubbly flows with the presence of heat and mass transfer processes. Subcooled boiling flow belongs to this specific category of bubbly flows is considered. The MUSIG (MUltiple-SIze-Group) model implemented in CFX4.4 is further developed to account for the wall nucleation and condensation in the...

Due to the dependence of boiling heat transfer rate on heat flux, saturation pressure, mass flux and refrigerant quality, efforts made to increase heat transfer rate often cause further drop in refrigerant saturation pressure. In this study, entropy generation mechanisms associated with two-phase flow in smooth evaporator tube subject to constant surface heat flux are investigated. Refrigerant ...

Phase change of pore fluid (boiling/condensing) in rock cores under conditions representative of geothermal reservoirs results in alterations of the electrical resistivity of the samples. In fractured samples, phase change can result in resistivity changes that are more than an order of magnitude greater than those measured in intact samples. These results suggest that electrical resistivity mo...