J.N. Chung^a,†, Tailian Chen^b, Shalabh C. Maroo^c

Frontiers in Heat and Mass Transfer, Vol.2, No.2, pp. 1-19, 2011, DOI:10.5098/hmt.v2.2.3004

Abstract Recent research progress in the area of nano/micro scale nucleate boiling is reviewed and an up-to-date summary is provided with a focus on the advances of fundamental boiling physics. This review examines nano/micro scale pool boiling experimental and theoretical/numerical work reported in the open literature. On the experimental side, the topics covered are moving contact line, critical heat flux, boiling curve, nucleation, single bubble boiling cycle, bubble coalescence boiling cycle, heater size effect, nanofluid, and nanoscale-structured heater surface. For the theoretical/numerical work, continuum mechanics modeling of the micro-region and molecular dynamics modeling of the nano-region are included. More >

Tomio Okawa^*,†

Frontiers in Heat and Mass Transfer, Vol.3, No.1, pp. 1-8, 2012, DOI:10.5098/hmt.v3.1.3001

Abstract The present article summarizes the studies on the thermalhydraulic condition under which the onset of nucleate boiling (ONB) is triggered in subcooled flow boiling. Available correlations and experimental data show that the ONB is tended to be delayed in mini and microchannels. It is known that the ONB condition is significantly dependent on the surface condition even in conventional-sized channels. Accumulation of ONB data accompanied by the information on the surface condition is therefore considered of importance to elucidate the mechanisms of boiling incipience in microchannels. Discussion is also made for the bubble dynamics observed in mini and microchannels. It… More >

Ayat N. Mahmood¹, Amer A. Abdulrahman¹, Laith S. Sabri^1,*, Abbas J. Sultan¹, Hasan Shakir Majdi², Muthanna H. Al-Dahhan³

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.2, pp. 239-256, 2024, DOI:10.32604/fdmp.2023.028015

Abstract Hydrodynamics characterization in terms of flow regime behavior is a crucial task to enhance the design of bubble column reactors and scaling up related methodologies. This review presents recent studies on the typical flow regimes established in bubble columns. Some effort is also provided to introduce relevant definitions pertaining to this field, namely, that of “void fraction” and related (local, chordal, cross-sectional and volumetric) variants. Experimental studies involving different parameters that affect design and operating conditions are also discussed in detail. In the second part of the review, the attention is shifted to cases with internals of various types (perforated… More >

Meng Jia, Mingjun Pang^*

Frontiers in Heat and Mass Transfer, Vol.21, pp. 337-366, 2023, DOI:10.32604/fhmt.2023.044286

Abstract The interphase mass, heat transfer efficiency, and flow resistance are strongly dependent on bubble size in gasliquid two-phase systems, so it is very important for engineering applications to effectively control bubble size. In this paper, the formation, growth, and detachment of single bubbles in Newtonian liquids based on capillary needles were studied in detail using a volume of fluid method. The authors investigated the effects of gas injection velocity, gravitational level, surface tension coefficient, needle radius, and liquid−phase properties (liquid viscosity and density) on the process of bubble generation, and the effects of the above factors on bubble shape, detachment… More >

Shaopeng Liu¹, Guowei Wang^2,3,*, Pengfei Liu¹, Dong Ye¹, Jian Song¹, Xing Liu¹, Yang Cheng^2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.12, pp. 3045-3058, 2023, DOI:10.32604/fdmp.2023.029810

Abstract Foam drainage is the flow of liquid through the interstitial spaces between bubbles driven by capillarity and gravity and resisted by viscous damping. The so-called foam drainage gas recovery technology is a technique traditionally used to mitigate the serious bottom-hole liquid loading in the middle and late stages of gas well production. In this context, determining the optimal concentration of the bubble drainage agent is generally crucial for the proper application of this method. In this study, a combination of indoor experiments and theoretical analysis have been used to determine the pressure drop related to the foam-carrying capacity in a… More >

Jianli Shao^1,2,*, Weidong Wei¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.09101

Abstract This report mainly introduces our recent research on the shock-induced collapse, migration and coalescence of He bubbles in metal based on atomistic simulations. The He bubble will be compressed to permanent deformation with the finite plastic collapse of metal. Under strong shock, the He bubble can be breakdown by the nano-jet of the metal, but it returns to a reduced sphere in the molten metal after long-time evolution, driven by the He-Al interface energy. Besides, the shock-induced migration of He bubble is revealed, which can be divided into shock acceleration and the following inertial motion. Moreover, two coalescence modes caused… More >

Touhami Baki^a,*, Djamel Sahel^a , Ahmed Guessab^b

Frontiers in Heat and Mass Transfer, Vol.9, pp. 1-7, 2017, DOI:10.5098/hmt.9.14

Abstract Boiling is influenced by a large number of parameters; the angle of orientation constitutes one of these parameters which have a positive impact on the heat transfer. The dynamic of the bubble plays a significant role in the improvement of heat transfer during boiling. For this reason, we are located on the bubble scale and we simulated the detachment of vapor bubble in the liquid water on a heated surface, when the angle of orientation varies from 0 to 180°. We followed the evolution of the sliding of the bubble; it appears that the thermal boundary layer is disturbed and… More >

Clement Roy^a,* , Prasanna Venuvanalingam^b , James F. Klausner^a , Renwei Mei^c

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-12, 2018, DOI:10.5098/hmt.11.1

Abstract This article presents both an experimental and numerical study of both stationary and sliding bubbles in a horizontal duct with forced convection heat transfer. An experimental facility was fabricated using a fully transparent, electrically-heated test section in which the bubble dynamics and the thermal field on the heated wall can be acquired using high-speed cameras and Thermochromic Liquid Crystals (TLC). Experiments were conducted using the working fluid HFE 7000 for two different turbulent Reynolds numbers. The experimental temperature field in the span-wise direction is first compared to the numerically calculated temperature field of a bubble sliding near a wall and… More >

Dalia S. Makki¹, Hasan Sh. Majdi², Amer A. Abdulrahman¹, Abbas J. Sultan^1,3,*, Zahraa W. Hasan¹, Laith S. Sabri^1,3, Bashar J. Kadhim¹, Muthanna H. Al-Dahhan³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2613-2637, 2023, DOI:10.32604/fdmp.2023.028081

Abstract Bubble and slurry bubble column reactors (BCRs/SBCRs) are used for various chemical, biochemical, and petrochemical applications. They have several operational and maintenance advantages, including excellent heat and mass transfer rates, simplicity, and low operating and maintenance cost. Typically, a catalyst is present in addition to biochemical processes where microorganisms are used to produce industrially valuable bio-products. Since most applications involve complicated gas-liquid, gas-liquid-solid, and exothermic processes, the BCR/SBCR must be equipped with heat-exchanging tubes to dissipate heat and control the reactor’s overall performance. In this review, past and very recent experimental and numerical investigations on such systems are critically discussed.… More >

Andrés Zapata^a , Carlos Amaris^b,*, Alexis Sagastume^a, Andrés Rodríguez^a

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-9, 2022, DOI:10.5098/hmt.19.33

Abstract The present study aims to assess the vapour bubble absorption into the ammonia/lithium nitrate (NH₃/LiNO₃) solution by using an optimized CFD model. A detailed methodology to build up the CFD model is presented, as well as its validation using experimental data. The operating conditions set corresponds to an absorption chiller driven by low-temperature heat sources such as solar energy in warm environments. Results evidenced that the Volume of Fluid and Mixture models are adequate to be used in the CFD model to predict the absorption process in the bubble absorber assessed depending on the mesh density refinement. Moreover, the heat… More >