When droplets coalesce on a superhydrophobic nanostructured surface, the resulting droplet can jump from the surface due to the release of excess surface energy. If designed properly, these superhydrophobic nanostructured surfaces can not only allow for easy droplet removal at micrometric length scales during condensation but also promise to enhance heat transfer performance. However, the ratio...

This thesis details the design and construction of a rig for studying surface condensation and a rig for creating anodized metal oxides (AMOs). The condensation rig characterizes condensation for different surfaces; this is done with the use of known heat transfer principles to calculate characteristic heat fluxes and heat transfer coefficient values. Preliminary results have been shown to foll...

This work presents procedures to compute the heat transfer coefficient when downwards flowing pure vapours (or azeotropic mixtures) condense on horizontal integral-fin tubes. At first, single tubes are considered, and the suggested procedure takes shear, gravity and surface tension force into account. The method is compared with a vast data bank demostrating a sound concordance. The second part...

cooling towers are widely used in most industrial units to reject waste heat to the atmosphere. this paper deals with an experimental analysis of heat and mass transfer phenomena between water and air by direct contact in a cooling tower. the tower is filled with 6 type packing. in this study temperature and pressure drop and tower characteristics was used in determining experimentally the ther...

Vehicles for future manned space missions will demand unprecedented increases in power requirements and heat dissipation. Achieving these goals while maintaining acceptable size and weight limits will require replacing present single-phase thermal management components with far more efficient twophase counterparts. This study discusses the development of an experimental facility for the study o...

in this work, the characteristics of flow and heat transfer of a fluid containing nano particles of aluminum oxide with the water volume fraction (0.1-0.2-0.3)(v/v) percent of the reports. the overall heat transfer coefficient, heat transfer and the average heat transfer fluid containing nano water - aluminum oxide in a horizontal double pipe counter flow heat exchanger under turbulent flow con...

Q. s. Yuan Electricite de France centre des Renardieres Departement Application de l'Electricite 77250 Moret sur Laing, France Noncondensable gases in a condenser will reduce the heat transfer coefficient and this is the case of the mixture (steam + air) j Rll4 heat exchanger in our high temperature heat pump. This heat exchanger is a shell tube type and is for the purpose of simulating industr...

Compared to the significant body of work devoted to surface engineering for promoting dropwise condensation heat transfer of steam, much less attention has been dedicated to fluids with lower interfacial tension. A vast array of low-surface tension fluids such as hydrocarbons, cryogens, and fluorinated refrigerants are used in a number of industrial applications, and the development of passive ...

When condensed droplets coalesce on a superhydrophobic nanostructured surface, the resulting droplet can jump due to the conversion of excess surface energy into kinetic energy. This phenomenon has been shown to enhance condensation heat transfer by up to 30% compared to state-of-the-art dropwise condensing surfaces. However, after the droplets jump away from the surface, the existence of the v...

Vapor condensation plays a key role in a wide range of industrial applications including power generation, thermal management, water harvesting and desalination. Fast droplet nucleation and efficient droplet departure as well as low interfacial thermal resistance are important factors that determine the thermal performances of condensation; however, these properties have conflicting requirement...