The Turbulence Modification in Bubbly Vertical Pipe Flow : Effect of Local Void Fraction and Bubble Diameter

2002 ◽  
Vol 2002 (0) ◽  
pp. 241-242
Author(s):  
Daiju MINATO ◽  
Tomohiko TANAKA ◽  
Akiko FUJIWARA ◽  
Koichi HISHIDA ◽  
Masanobu MAEDA
Keyword(s):  
Void Fraction ◽  
Pipe Flow ◽  
Bubble Diameter ◽  
Vertical Pipe ◽  
Flow Effect ◽  
Turbulence Modification

Numerical Study on Turbulence Modification in Particle-Laden Pipe Flows

2011 ◽  
Vol 130-134 ◽  
pp. 3603-3606
Author(s):  
Fu Sheng Yan ◽  
Wei Jun Zhang ◽  
Ru Quan Liang
Keyword(s):  
Experimental Data ◽  
Turbulent Flows ◽  
Pipe Flow ◽  
Numerical Study ◽  
Vertical Pipe ◽  
Pipe Flows ◽  
Dilute Gas ◽  
Turbulence Modification ◽  
Proposed Model ◽  
Simulation Results

This investigation deals with the study on the processes involved in the phenomenon about turbulence modification in dilute gas-particle turbulent flows. The proposed model, along with other selected turbulence modification models from the literature, is used to simulate a particle-laden vertical pipe flow. The simulation results show that the new model provides improved predictions of the experimental data.

Mass Transfer From a Bubble in a Vertical Pipe

2011 ◽  
Author(s):  
Shogo Hosoda ◽  
Ryosuke Sakata ◽  
Kosuke Hayashi ◽  
Akio Tomiyama
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Bubble Diameter ◽  
Vertical Pipe ◽  
Oblate Spheroidal ◽  
Wide Range ◽  
Bubble Sizes ◽  
Small Bubbles ◽  
Taylor Bubbles

Mass transfer from single carbon dioxide bubbles in a vertical pipe is measured using a stereoscopic image processing method to develop a mass transfer correlation applicable to a wide range of bubble and pipe diameters. The pipe diameters are 12.5, 18.2 and 25.0 mm and the bubble diameter ranges from 5 to 26 mm. The ratio, λ, of bubble diameter to pipe diameter is therefore varied from 0.2 to 1.8, which covers various bubble shapes such as spherical, oblate spheroidal, wobbling, cap, and Taylor bubbles. Measured Sherwood numbers, Sh, strongly depend on bubble shape, i.e., Sh of Taylor bubbles clearly differs from those of spheroidal and wobbling bubbles. Hence two Sherwood number correlations, which are functions of the Peclet number and the diameter ratio λ, are deduced from the experimental data: one is for small bubbles (λ < 0.6) and the other for Taylor bubbles (λ > 0.6). The applicability of the proposed correlations for the prediction of bubble dissolution process is examined through comparisons between measured and predicted long-term bubble dissolution processes. The predictions are carried out by taking into account the presence of all the gas components in the system of concern, i.e. nitrogen, oxygen and carbon dioxide. As a result, good agreements for the dissolution processes for various bubble sizes and pipe diameters are obtained. It is also demonstrated that it is possible to evaluate an equilibrium bubble diameter and instantaneous volume concentration of carbon dioxide in a bubble using a simple model based on a conservation of gas components.

scholarly journals Experimental Study on Interfacial Area Transport of Two-Phase Flow under Vibration Conditions

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Xiu Xiao ◽  
Qingzi Zhu ◽  
Shao-Wen Chen ◽  
Mamoru Ishii ◽  
Yajun Zhang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Void Fraction ◽  
Vibration Frequency ◽  
Two Phase Flow ◽  
Bubble Diameter ◽  
Interfacial Area ◽  
Phase Flow ◽  
Two Phase ◽  
Vibration Direction ◽  
Local Parameters

An experimental study on air-water two-phase flow under vibration condition has been conducted using double-sensor conductivity probe. The test section is an annular geometry with hydraulic diameter of 19.1 mm. The vibration frequency ranges from 0.47 Hz to 2.47 Hz. Local measurements of void fraction, interfacial area concentration (IAC), and Sauter mean diameter have been performed along one radius in the vibration direction. The result shows that local parameters fluctuate continuously around the base values in the vibration cycle. Additional bubble force due to inertia is used to explain lateral bubble motions. The fluctuation amplitudes of local void fraction and IAC increase significantly with vibration frequency. The radial distribution of local parameters at the maximum vibration displacement is specifically analyzed. In the void fraction and IAC profiles, the peak near the inner wall is weakened or even disappearing and a strong peak skewed to outer wall is gradually observed with the increase of vibration frequency. The nondimensional peak void fraction can reach a maximum of 49% and the mean relative variation of local void fraction can increase to more than 29% as the vibration frequency increases to 2.47 Hz. But the increase of vibration frequency does not bring significant change to bubble diameter.

scholarly journals Numerical Simulation of Oil Dispersions in Vertical Pipe Flow

2010 ◽  
Vol 53 (1) ◽  
pp. 42-54 ◽  
Author(s):  
Mahdi Parvini ◽  
Bahram Dabir ◽  
Seyed Abolfazl Mohtashami
Keyword(s):  
Numerical Simulation ◽  
Pipe Flow ◽  
Vertical Pipe
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