This report summarizes our three-year effort on advanced micro and nanostructures for fundamental studies of fluid manipulation and enhanced two-phase heat transfer. First, we studied the role of micro/nanostructures on pool boiling heat transfer. We fabricated well-defined microstructured surfaces in silicon and performed systematic pool boiling experiments in which we demonstrated that increa...

The paper presents the results of experimental research on pool boiling heat transfer dielectric liquid FC-72. Measurements were made at atmospheric pressure open surfaces with microchannels. Heat surfaces, in form parallel milled microchannels, copper. rectangular cross-sectional microchannels 0.2 to 0.5 mm deep and 0.4 wide. compared a smooth flat surface, provided five-fold increase coeffici...

A passive residual heat removal exchanger (PRHR HX) was used as the research object, and an experimental device with conduction oil source set up to complete study of outside tube saturation boiling. The improved Wilson diagram method calculate data, transfer law boiling smooth finned obtained. Compared two types tubes, intensification rate 1.07, that 2.39, 2.23 times tube. According rate, Nu m...

Micro scale boiling behavior in the vicinity of graphite micro-fiber tips on the coppergraphite composite boiling surfaces is investigated. It is discovered that a large number of micro bubbles are formed first at the micro scratches and cavities on the copper matrix in pool boiling. In virtue of the non-wetting property of graphite, once the growing micro bubbles touch the graphite tips, the m...

During the last half of the twentieth century, significant advances have been made in developing an understanding of phase change heat transfer (e.g., boiling and condensation). Further advances in phase change heat transfer will continue to take place motivated by new technologies such as microelectronics, thermal management in space, advanced terrestrial and space power systems and processing...

The use of immiscible liquids for cooling of surfaces with high heat generation density is proposed based on the experimental verification of its superior cooling characteristics in fundamental systems of pool boiling and flow boiling in a tube. For the purpose of practical applications, however, heat transfer characteristics due to flow boiling in narrow rectangular channels with different sma...

simulation of turbulence boiling, generation of vapour and predication of its behaviour are still subject to debate in the two-phase flow area and they receive a high level of worldwide attention. in this study, a new arrangement of the three dimensional governing equations for turbulence two-phase flow with heat and mass transfer are derived by using ensemble averaging two-fluid model and util...

Molecular dynamics simulations were employed to investigate the effects of wettability (contact angle) and pitch on nanoscale evaporation and pool boiling heat transfer of a liquid argon thin film on a horizontal copper substrate topped with cubic nano-pillars. The liquid–solid potential was incrementally altered to vary the contact angle between hydrophilic (∼0°) and hydrophobic (∼127°), and t...

abstract: in this paper, a new population-based search called the bees algorithm (ba) is presented to estimate the time-dependent heat transfer coefficient and the corresponding heat flux at the boundaries of a two-dimensional body subjected to transient heat conduction, using the temperature measurements at discrete nodal locations on the boundaries, where heat flux is specified as the boundar...

The cooling of the steel strip in ROT (run out table) of the hot rolling process is very important in that the ROT is the final process to control the mechanical properties of the final products. In general the products are cooled by the circular water jets which makes the comparatively thick residual water layer about 100–200 mm with the supplied flow rate on the plate. The basic phenomenon go...