... with nine different contact angles (38 deg ≤ θ ≤ 128 deg) and varying air flow rates (1–300 ml/min) were made using high speed videography and image processing. In the static or constant-volume regime, below a critical contact angle θ c , the bubble base remains attached to the orifice, and the equivalent...

... is tracked by a sharp-interface level-set method, which is extended to include the effects of evaporation at the liquid–gas interface and dynamic contact angle at the liquid–gas–solid interline. The numerical results show that the droplet impact and evaporation pattern depends significantly on the advancing...

.... The mass flux was set at 100 kg/m 2 s and the base heat flux varied from 30 to 80 kW/m 2 . Water enters the test channel under subcooled conditions. The samples are silicon oxide (SiOx), titanium (Ti), diamond-like carbon (DLC), and carbon-doped silicon oxide (SiOC) surfaces with static contact angles...

...Xuehu Ma; Sifang Wang; Zhong Lan; Benli Peng; H. B. Ma; P. Cheng It is well known that heat transfer in dropwise condensation (DWC) is superior to that in filmwise condensation (FWC) by at least one order of magnitude. Surfaces with larger contact angle (CA) can promote DWC heat transfer due...

...Satish G. Kandlikar 19 07 2011 27 07 2011 29 11 2011 29 11 2011 boiling contact angle evaporation heat transfer microchannel flow surface tension The interrelations among different nondimensional groups shown by M. M. Awad are quite correct. The insight...

..., for the experiments at the ISS, just water was used. A model was developed to predict the maximum heat transfer capacity of the device. In comparison to the literature models, the main difference of the present model is the variation of contact angle to adjust the mathematical model. Therefore, the main contributions...

...Sunwoo Kim; Kwang J. Kim A mathematical model is developed to represent and predict the dropwise condensation phenomenon on nonwetting surfaces having hydrophobic or superhydrophobic (contact angle greater than 150 deg) features. The model is established by synthesizing the heat transfer through...

...Jae Bong Lee; Seong Hyuk Lee; Chang Kyoung Choi aluminium contact angle drops flow visualisation high-speed optical techniques hole density hydrophobicity impact (mechanical) microfluidics milling machines surface energy surface roughness surface texture water wetting 27...

...Yulong Ji; Hsiu-hung Chen; Qingsong Yu; Xuehu Ma; H. B. Ma 27 04 2011 27 04 2011 coatings contact angle cooling copper hydrophobicity monolayers organic compounds self-assembly wetting 2011 American Society of Mechanical Engineers ...

... physical processes taking place during condensation. These include growth due to direct condensation, droplet coalescence, sliding, fall-off, and renucleation of droplets. The effects arising from lyophobicity, namely, the contact angle variation and its hysteresis, inclination of the substrate...

... condensation form is still not clear. We suggest a condensation model based on droplet nucleation and growth on elevated precipitates, resulting in short-term steam entrapment after droplet coalescence. According to the wetting theory, this transition state yields increased macroscopic contact angles...

...C. Dietz; K. Rykaczewski; A. Fedorov; Y. Joshi condensation contact angle copper compounds drops heat transfer hydrophobicity nanostructured materials scanning electron microscopy wetting 11 06 2010 11 06 2010 2010 American Society of Mechanical Engineers ...

...Dong Hwan Shin; Seong Hyuk Lee; Scott Retterer; Chang Kyoung Choi 11 06 2010 11 06 2010 contact angle drops evaporation flow visualisation hydrophobicity two-phase flow water wetting 2010 American Society of Mechanical Engineers ...

.... 121013 ) is verified in this part. In the first step, the model is examined by experiments conducted using R134a covering a range of pressures, inlet subcoolings, and flow velocities. The density of the active nucleation sites is measured and correlated with critical diameter D c and static contact angle...

...H. K. Dhavaleswarapu; C. P. Migliaccio; S. V. Garimella; J. Y. Murthy 28 05 2009 contact angle drops evaporation flow visualisation heat transfer water 2009 American Society of Mechanical Engineers ...

... a wide range of tested conditions. The potential of this new approach and possible refinements that will add engineering value are discussed. 07 12 2007 18 06 2008 18 03 2009 condensation contact angle heat exchangers heat transfer wetting condensation retention...

... conduction. The local wall heat transfer is found to vary significantly along the meniscus base, the highest being near the advancing contact line. The heat transfer coefficient is found to depend on the advancing contact angle and wall velocity but is independent of the wall superheat. Reasonable agreement...

...-steady state pure system was significantly larger (smaller length and larger apparent contact angle at δ = 0.1 μ m ) than the isothermal value, whereas the reverse occurred for the mixture. Using a continuum model, a comparison of numerically obtained Marangoni stresses and local evaporative heat flux...

... characteristics on the superhydrophilic surface are significantly different from those on the common metal surface. The CHF of boiling on the superhydrophilic surface is greatly increased by decreasing of the solid-liquid contact angle. Comparison of CHF between the superhydrophilic surface and copper surface...

...A. I. ElSherbini; A. M. Jacobi A model has been developed for predicting the amount of condensate retained as drops on the air-side of heat exchangers operating under dehumidifying conditions. For a coil with a given surface wettability, characterized by the advancing contact angle, the maximum...