... is small (typical dimension around 1 mm), surface tension effects become important, especially for noncircular section channels, and calculation methods based on data for larger hydraulic diameter channels are unsatisfactory. In addition, pressure drop affects heat transfer and vice versa so that iterative...

...Andrea Dziubek The problem is characterized by two small length scales (tube radius and initial film thickness) and the tube length. We showed that to include the effect of surface tension due to surface waves terms up to order ( H / L ) 2 need to remain in the equations...

... into account surface tension. A uniform interface temperature and a uniform wall temperature have been fixed as boundary conditions. The mass flux is G = 100 kg m −2 s −1 and it has been assumed that the flow is laminar inside the liquid phase while turbulence inside the vapor phase has been handled...

... relationship with the strength and properties of the fusion zone. In this work, surface tension coefficient is considered to be negative, indicating an outward surface flow, whereas high Prandtl number represents a reduced thickness of the thermal boundary layer compared to that of the momentum boundary layer...

... of thermal expansion [1/K] λ = thermal conductivity [W/(m·K)] μ = dynamic viscosity [Pa·s] ν = kinematic viscosity [m 2 /s] ν ¯ = mean kinematic viscosity [m 2 /s] σ = surface tension [N/m] σ T = temperature coefficient of surface tension [N/(m·K...

...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...

... area of the tubes, i.e., on the surface area of the parts of the tube and pin surface not covered by condensate retained by surface tension. For all the tubes, vapor-side, heat-transfer enhancements were found to be approximately twice the corresponding active-area enhancements. The best performing pin...

.... The power law coefficient for gravity is a function of wall temperature. As the heater size or gravity level is reduced, a sharp transition in the heat flux is observed at a threshold value of L h /L c = 2.1. Below this threshold value, boiling is surface tension dominated and the dependence on gravity...

... friction multiplier is shown to decrease as channel diameter decreases due to the influence of viscous and surface tension forces. 06 09 2010 10 05 2011 15 08 2011 15 08 2011 air drag forced convection microchannel flow pattern formation surface tension two-phase flow...

...Ian A. Cosden; Jennifer R. Lukes Molecular dynamics simulations are performed to calculate the surface tension of bubbles formed in a metastable Lennard–Jones (LJ) argon fluid. The calculated normal and transverse pressure components are used to compute a surface tension which is compared...

...Nenad Miljkovic; Ryan Enright; Shalabh C. Maroo; H. Jeremy Cho; Evelyn N. Wang capillarity drops elemental semiconductors evaporation flow visualisation hydrophilicity hydrophobicity nanostructured materials scanning electron microscopy silicon surface tension two-phase flow...

... , “ On the Conditions for Stability of Falling Films Subject to Surface Tension Disturbances; the Condensation of Binary Vapors ,” Can. J. Chem. Eng. 0008-4034 , 46 , pp. 309 – 312 . 10.1002/cjce.5450460505 Hijikata , K. , Fukasaku , Y. , and Nakabeppu , O. , 1996 , “ Theoretical...

... % ( 7.51 wt % ) are investigated and compared with predictions developed for conventional fluids. The thermophysical properties of the nanofluids, including thermal conductivity, kinematic viscosity, and surface tension, are reported, as is the mode transition behavior of the nanofluids. The experimental...

...T. W. Dutton; L. R. Pate; D. K. Hollingsworth Surface-tension forces can drive fluid motion within thin liquid layers with a free surface. Spatial variations in the temperature of the free surface create surface tractions that drive cellular motions. The cells are most commonly hexagonal in shape...

...Rishi Raj; Jungho Kim A pool boiling regime map demarcating the boundary between the surface tension and buoyancy dominated boiling regimes is developed based on heater size and gravity. For large heaters and/or high gravity conditions, boiling is dominated by buoyancy, and the ebullition cycle...

.... Using these forces, a local parameter model is developed to predict the flow boiling CHF. The theoretical model is an extension of an earlier pool boiling CHF model and incorporates force balance among the evaporation momentum, surface tension, inertia, and viscous forces. Weber number, capillary number...

... density, kg   m − 3 σ surface tension, N   m − 1 This work was supported by the Office of Naval Research (Program Officer Mark Spector). The microfabrication was performed in part at the Cornell NanoScale Facility (a member of the National...

... through numerical modeling is needed to design efficient spray cooling system. A computational fluid dynamics based 3D multiphase model for spray cooling is developed here in parallel computing environment using multigrid conjugate gradient solver. This model considers the effect of surface tension...

... 25 06 2009 boiling bubbles capillarity convection nucleation organic compounds surface tension zero gravity experiments boiling variable gravity microgravity thermocapillary convection dissolved gas heater size Pool boiling involves complicated nonlinear processes...

...Hulin Huang; Xiaoming Zhou When a temperature gradient is imposed along a liquid-liquid interface, thermocapillary convection is driven by the surface tension gradient. Such flow occurs in many application processes, such as thin-film coating, metal casting, and crystal growth. In this paper...