Boiling is a very efficient way to transfer heat from a heater to the liquid carrier. We discuss the boiling crisis, a transition between two regimes of boiling: nucleate and film boiling. The boiling crisis results in a sharp decrease in the heat transfer rate, which can cause a major accident in industrial heat exchangers. In this communication, we present a physical model of the boiling cris...

The effects of dissolved air in the dielectric liquid FC-77 on flow boiling in a microchan-nel heat sink containing ten parallel channels, each 500 ␮m wide and 2.5 mm deep, were experimentally investigated. Experiments were conducted before and after degas-sing, at three flow rates in the range of 30– 50 ml/ min. The dissolved air resulted in a significant reduction in wall temperature at which...

This paper reviews the previous work carried on pool boiling heat transfer during heating of various liquids and commodities categorized as refrigerants and dielectric fluids, pure liquids, nanofluids, hydrocarbons and additive mixtures, as well as natural and synthetic colloidal solutions. Nucleate pool boiling is an efficient and effective method of boiling because high heat fluxes are possib...

Cross-corrugated triangular channels increase heat transfer in heat exchangers. The mixing effect increases the heat transfer coefficient at the surfaces. In this study, the fluid flow and heat transfer in a triangular corrugated channel are modeled under two constant heat fluxes and different Reynolds numbers. In order to validate, k-ω turbulence model is used. Also, the effect of magnetic fie...

Boiling--a process that has powered industries since the steam age--is governed by bubble formation. State-of-the-art boiling surfaces often increase bubble nucleation via roughness and/or wettability modification to increase performance. However, without active in situ control of bubbles, temperature or steam generation cannot be adjusted for a given heat input. Here we report the ability to t...

Molecular dynamics (MD) simulations were employed to investigate the effect of wettability (via contact angle variation) on nanoscale 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 in order to vary the contact angle between hydrophilic (θ~63°) and super hydrophobic (θ~15...

viii transfer coefficient in the channels, which is effective in flattening thermal gradients from non-uniform heating within the chip stack. Flow boiling of refrigerants 236fa and 1234ze (R236fa & R1234ze) were experimentally investigated within two different test sections. First-of-a-kind high pressure fluidic tests were successfully achieved within a 3D chip stack with interlayer cooling cap...

the present experimental study reports on enhancement of heat transfer by addition of nanoparticles to the working fluid of commercial swimming pool heat exchangers under laminar flow condition. three different concentrations of titanium dioxide nanoparticles were added to the water as working fluid of a typical forced convective heat exchanger used to transfer heat to public swimming pools. th...

the presence of particles in liquid-solid fluidized beds enhances the bed heat transfer, because the movement of the particles leads to an increased turbulence in the system. moreover, the violent movement of the particles has a positive effect on fouling of the heat transfer surface. the aim of this investigation was to perform systematic measurements of bed voidage and heat transfer coefficie...