One of the major industry problems is the flow boiling, where reaching to the critical heat flux (CHF) condition can lead to a temperature jump and damage of the systems. In the present study, the effects of a uniform change in tube diameter on subcooled flow boiling and CHF was numerically investigated. The Euler-Euler model was used to investigate the relationship between the two liquid and v...

eunsteady slip-flow of second grade non-newtonian electrically conducting fluid over an oscillating sheet has been considered and solved numerically. a second-order slip velocity model is used to predict the flow characteristic over the wall. with the assumption of infinite length in the x-direction, the velocity of the fluid can be assumed as a function of y and t, hence, with proper change va...

Two-phase forced convective flow in microchannels is promising for the cooling of integrated circuits. There has been limited research on boiling flow in channels with dimensions below 100 m, in which bubble formation and flow regimes can differ from those in larger channels. This work develops single and multichannel experimental structures using plasma-etched silicon with pyrex glass cover, w...

4 Q B A multi-faceted instrumentation approach is described which has played a significant role in ob*ing fundamental data for two-phase flow model development. This experimental work supports the development of a three-dimensional, two-fluid, four field computational analysis capability. The god of this development is to utilize mechanistic models and fundamental understanding rather than rely...

Flow boiling in microchannel heat sinks is considered as a promising cooling solution for electronic components. Higher flux can be effectively dissipated by the utilization of latent vaporization. However, most current studies on flow microchannels are mainly experimental investigations and two-dimensional numerical studies. In this paper, Volume Fluid (VOF) model combined with Lee evaporation...

Pool boiling experiments were conducted with three horizontal, flat, silicon surfaces, two of which were coated with vertically aligned multiwalled carbon nanotubes (MWCNTs). The two wafers were coated with MWCNT of two different thicknesses: 9 m (Type-A) and 25 m (Type-B). Experiments were conducted for the nucleate boiling and film boiling regimes for saturated and subcooled conditions with l...

Heat transfer during flow boiling in minichannels and microchannels is intimately linked to the liquid-vapor phase distribution in the channels. The vapor phase exists as nucleating bubbles, dispersed bubbles, elongated bubbles, an annular core, or all vapor flow completely filling the channel. Similarly, the liquid can exist as bulk liquid, slugs, thin film on the heated wall, or dispersed dro...