Abo Bibliothek: Guest
ICHMT DL Home Aktuelles Jahr Archive Vorstand International Centre for Heat and Mass Transfer

Microbubble coalescence and breakup in turbulent vertical channel flows

DOI: 10.1615/THMT-18.520
pages 523-534

K.S. Asiagbe
School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK

Michael Fairweather
School of Chemical and Process Engineering, University of Leeds, Leeds, LS2 9JT, UK

Derrick O. Njobuenwu
School of Chemical and Process Engineering, University of Leeds, Leeds, LS2 9JT, UK

M. Colombo
Institute of Particle Science and Engineering, School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom


Large eddy simulation coupled to Lagrangian bubble tracking is used to study four-way coupled turbulent bubbly flow in channels, including bubble collision, coalescence and breakup. Upward and downward vertical channel flows of water at shear Reynolds numbers of 150 and 2000 are examined, with air bubbles of diameter db= 220 µm dispersed within the flows. Additional simulations are performed for the case of refrigerant R134a at a shear Reynolds number of 1154. The ability of the model to predict coalescence and breakup is evaluated, as well as the impact of the flow condition on the two phenomena. Coalescence and breakup are favoured in upflow conditions, with turbulence found to significantly impact the level of bubble interaction. Coalescence is dominant at low turbulence levels and breakup, which was only detected in the R134a flow, is favoured at high turbulence. The results demonstrate the capabilities of the overall model to predict bubble coalescence and breakup, and its usefulness for predicting flows that are of industrial relevance where interfacial area and bubble size distribution govern interfacial mass, momentum and heat transfer processes.

ICHMT Digital Library

Bow shocks on a jet-like solid body shape. Thermal Sciences 2004, 2004. Pulsed, supersonic fuel jets - their characteristics and potential for improved diesel engine injection. PULSED, SUPERSONIC FUEL JETS - THEIR CHARACTERISTICS AND POTENTIAL FOR IMPROVED DIESEL ENGINE INJECTION
View of engine compartment components (left). Plots of temperature distributions in centreplane, forward of engine (right). CHT-04 - Advances in Computational Heat Transfer III, 2004. Devel... DEVELOPMENT AND CURRENT STATUS OF INDUSTRIAL THERMOFLUIDS CFD ANALYSIS
Pratt & Whitney's F-135 Joint Strike Fighter Engine under test in Florida is a 3600F class jet engine. TURBINE-09, 2009. Turbine airfoil leading edge stagnation aerodynamics and heat transfe... TURBINE AIRFOIL LEADING EDGE STAGNATION AERODYNAMICS AND HEAT TRANSFER - A REVIEW
Refractive index reconstructed field. (a) Second iteration. (b) Fourth iteration. Radiative Transfer - VI, 2010. Theoretical development for refractive index reconstruction from a radiative ... THEORETICAL DEVELOPMENT FOR REFRACTIVE INDEX RECONSTRUCTION FROM A RADIATIVE TRANSFER EQUATION-BASED ALGORITHM
Two inclusion test, four collimated sources. Radiative Transfer - VI, 2010. New developments in frequency domain optical tomography. Part II. Application with a L-BFGS associated to an inexa... NEW DEVELOPMENTS IN FREQUENCY DOMAIN OPTICAL TOMOGRAPHY. PART II. APPLICATION WITH A L-BFGS ASSOCIATED TO AN INEXACT LINE SEARCH