The composition shifts of multicomponent mixtures used in low temperature Joule-Thomson refrigerators due to the different solubility in lubricant oils are studied in this paper. A compound of squalane with a high-boiling point temperature is treated as a kind of mineral oil. The Peng-Robinson (PR) equation of state (EOS) is selected to predict the solubilities, in which a group contribution mo...

The state-of-the-art for Direct Numerical Simulation (DNS) of boiling multiphase flows is reviewed, focussing on potential of available computational techniques, the level of current success for their applications to model several basic flow regimes (film, pool-nucleate and wall-nucleate boiling – FB, PNB and WNB, respectively). Then, we discuss multiphysics and multiscale nature of practical b...

a method for predicting liquid densities of binary mixtures from heat of vaporization and liquid densityat boiling point temperature (δhvap and n b ρ ) as scaling constants, is presented. b2(t) follows a promisingcorresponding-states principle. calculation of α(t) and b(t), the two other temperature-dependentconstants of the equation of state, are made possible by scaling. as a result δhvap and...

nucleate pool boiling heat transfer coefficient have been experimentally measured on a horizontal rod heater for various liquid binary mixtures. measurements are based on more than three hundred data points on a wide range of concentrations and heat fluxes. in this investigation, it has been confirmed that the heat transfer coefficient in boiling solutions are regularly less than those in pure ...

The heat transfer model of the RELAP5/MOD3.1 (R5M3) code was extensively reviewed and assessed. The most important deficiency of the current version of the code was attributed to its treatment of the transition boiling heat transfer regime. The current transition boiling model significantly underpredicts the heat transfer rate to the liquid phase. Since at low quality conditions the liquid boil...

The forces due to surface tension and momentum change during evaporation, in conjunction with the forces due to viscous shear and inertia, govern the two-phase flow patterns and the heat transfer characteristics during flow boiling in microchannels. These forces are analyzed in this paper, and two new nondimensional groups, K1 and K2 , relevant to flow boiling phenomenon are derived. These grou...

We present a lattice Boltzmann method that has the capability of simulating thermodynamic multiphase flows. This approach is fully thermodynamically consistent at the macroscopic level. Using this method, the liquid-vapor boiling process, including liquid-vapor formation and coalescence together with a full coupling of temperature, is simulated.

Nucleate pool boiling heat transfer coefficient have been experimentally measured on a horizontal rod heater for various liquid binary mixtures. Measurements are based on more than three hundred data points on a wide range of concentrations and heat fluxes. In this investigation, it has been confirmed that the heat transfer coefficient in boiling solutions are regularly less than those in p...

We report that liquids perform self-propelled motion when they are placed in contact with hot surfaces with asymmetric (ratchetlike) topology. The pumping effect is observed when the liquid is in the Leidenfrost regime (the film-boiling regime), for many liquids and over a wide temperature range. We propose that liquid motion is driven by a viscous force exerted by vapor flow between the solid ...

We report that liquids perform self-propelled motion when they are placed in contact with hot surfaces with asymmetric (ratchet-like) topology. The pumping effect is observed when the liquid is in the film-boiling regime, for many liquids and over a wide temperature range. We propose that liquid motion is driven by a viscous force exerted by vapor flow between the solid and the liquid.