01898nas a2200205   4500008004100000245006600041210006600107260010600173300001400279490000700293520119700300653001101497653001801508653001601526653001801542653000801560653001501568100002301583856008601606       2008                        eng d00aExperimental analysis of the lift force on bubbles in a swarm0 aExperimental analysis of the lift force on bubbles in a swarm  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcOCT  a1710-17230 v633 a<p>The lift force acting on bubbles in a swarm has been estimated by analyzing the instantaneous velocity-time data obtained using LDA in a cylindrical bubble column. Phase distinction was achieved through the multiresolution analysis of the velocity-time data. Several important issues related to the transverse motion of bubbles subjected to a shear field have been discussed quantitatively. The actually measured bubble sizes, the respective slip velocity values in transverse and axial directions and the local shear rates (gamma) enabled the verification of known formulations for the lift coefficient (C-L) for bubbles. At many locations in the column the radial flux of the gas phase by turbulent dispersion and the radial slip were estimated. The radially inward movement of bubbles from low to high axial velocity (from column wall to center, i.e., C-L &lt; 0) was observed at most of the measurement locations. The local lift coefficient was estimated using the transverse drag force and the values support the results from the material balance approach. The estimated C-L values showed a wide variation over the column cross-section. (c) 2007 Elsevier Ltd. All rights reserved.</p>10aBubble10aBubble column10abubble size10ahydrodynamics10aLDA10alift force1 aKulkarni, Amol, A.  uhttps://library.ncl.res.in/content/experimental-analysis-lift-force-bubbles-swarm02254nas a2200229   4500008004100000022001400041245011800055210006900173260010600242300001200348490000800360520138400368653001101752653002201763653001201785653000901797653001601806653003001822100002301852700002201875856012701897       2013                        eng d  a0009-250900aDirect contact heat transfer via injecting volatile liquid in a hot liquid pool: generation and motion of bubbles0 aDirect contact heat transfer via injecting volatile liquid in a   aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcAUG  a421-4320 v1003 a<p>Direct contact heat transfer via injection of volatile liquid is an effective strategy for removing heat from a viscous liquid pool. The rapid evaporation effectively removes heat and the generated bubbles move quickly to the top surface. In this paper, we present an experimental and phenomenological analysis of the evaporation of a drop in a slightly miscible liquid. The phenomenon was visualized using a two-dimensional transparent experimental set-up with a single inlet at the bottom. The videos were used to estimate bubble dimensions, its rise velocity, distance from the detachment point, and fraction of vapor and the liquid phases in the evaporating drop. The initial drop size, temperature difference between the hot fluid and the low boiling solvent and the nucleation rate governed the rate of change of the drobble (combined entity of drop and bubble) diameter and its rise velocity. A phenomenological model describing transient behavior of drobble (motion and heat transfer) is developed. The transient variation in the interfacial areas for heat transfer and the projected area were found to have effect on the predictions. The model and results will also provide useful basis for extending the work towards better understanding of direct contact heat transfer in viscous systems like polymerization reactors. (C) 2013 Elsevier Ltd. All rights reserved.</p>10aBubble10aDirect contact HT10aDrobble10aDrop10aEvaporation10aSlightly miscible liquids1 aKulkarni, Amol, A.1 aRanade, Vivek, V.  uhttps://library.ncl.res.in/content/direct-contact-heat-transfer-injecting-volatile-liquid-hot-liquid-pool-generation-and-0