Investigation of Liquid Flow in a Multi-Pass Branching Microchannel System

2012 ◽  
Author(s):  
Ercan M. Dede
Keyword(s):  
Liquid Flow ◽  
Recent Progress ◽  
Flow Behavior ◽  
Measured Data ◽  
Microchannel Heat Sink ◽  
Cold Plate ◽  
Flow Rates ◽  
Flow Simulations ◽  
Numerical Predictions ◽  
Good Agreement

The design and fabrication of a unique multi-pass branching microchannel heat sink is reviewed. The liquid flow inside of the cold plate is investigated both experimentally and numerically. The experiments are carried out over a range of flow rates, and the pressure drop across the cold plate is determined over the set of tested values. Comparisons are made between fluid flow simulations and the experimental results. Numerical predictions show good agreement with the measured data, and the effects of the connection taps, inlet/outlet manifolds, and flow behavior inside of the multi-pass region of the cooler are explained. Applications of the technology are briefly introduced, and recent progress toward heat transfer measurements is reported.

Unified Model for Gas-Liquid Pipe Flow Via Slug Dynamics: Part 2 — Model Validation

2002 ◽  
Author(s):  
Hong-Quan Zhang ◽  
Qian Wang ◽  
Cem Sarica ◽  
James P. Brill
Keyword(s):  
Experimental Data ◽  
Liquid Flow ◽  
Pipe Flow ◽  
Flow Behavior ◽  
Two Phase ◽  
Flow Rates ◽  
Inclination Angles ◽  
Gas Liquid Flow ◽  
Extensive Experimental Data ◽  
Good Agreement

In Zhang et al. [1], a unified hydrodynamic model is developed for prediction of gas-liquid pipe flow behavior based on slug dynamics. In this study, the new model is validated with extensive experimental data acquired with different pipe diameters, inclination angles, fluid physical properties, gas-liquid flow rates and flow patterns. Good agreement is observed in every aspect of the two-phase pipe flow.

Unified Model for Gas-Liquid Pipe Flow via Slug Dynamics—Part 2: Model Validation

2003 ◽  
Vol 125 (4) ◽  
pp. 274-283 ◽  
Author(s):  
Hong-Quan Zhang ◽  
Qian Wang ◽  
Cem Sarica ◽  
James P. Brill
Keyword(s):  
Experimental Data ◽  
Liquid Flow ◽  
Pipe Flow ◽  
Flow Behavior ◽  
Two Phase ◽  
Flow Rates ◽  
Inclination Angles ◽  
Gas Liquid Flow ◽  
Extensive Experimental Data ◽  
Good Agreement

In Zhang et al. [1], a unified hydrodynamic model is developed for prediction of gas-liquid (co-current) pipe flow behavior based on slug dynamics. In this study, the new model is validated with extensive experimental data acquired with different pipe diameters, inclination angles, fluid physical properties, gas-liquid flow rates and flow patterns. Good agreement is observed in every aspect of the two-phase pipe flow.

The effect of two-phase flow regime on hydrodynamics and mass transfer in a horizontal-tube gas-liquid reactor

1985 ◽  
Vol 50 (3) ◽  
pp. 745-757 ◽  
Author(s):  
Andreas Zahn ◽  
Lothar Ebner ◽  
Kurt Winkler ◽  
Jan Kratochvíl ◽  
Jindřich Zahradník
Keyword(s):  
Mass Transfer ◽  
Pressure Drop ◽  
Flow Regime ◽  
Liquid Flow ◽  
Horizontal Tube ◽  
Liquid Holdup ◽  
Two Phase ◽  
Flow Rates ◽  
Type Relation ◽  
Good Agreement

The effect of two-phase flow regime on decisive hydrodynamic and mass transfer characteristics of horizontal-tube gas-liquid reactors (pressure drop, liquid holdup, kLaL) was determined in a cocurrent-flow experimental unit of the length 4.15 m and diameter 0.05 m with air-water system. An adjustable-height weir was installed in the separation chamber at the reactor outlet to simulate the effect of internal baffles on reactor hydrodynamics. Flow regime maps were developed in the whole range of experimental gas and liquid flow rates both for the weirless arrangement and for the weir height 0.05 m, the former being in good agreement with flow-pattern boundaries presented by Mandhane. In the whole range of experi-mental conditions pressure drop data could be well correlated as a function of gas and liquid flow rates by an empirical exponential-type relation with specific sets of coefficients obtained for individual flow regimes from experimental data. Good agreement was observed between values of pressure drop obtained for weirless arrangement and data calculated from the Lockhart-Martinelli correlation while the contribution of weir to the overall pressure drop was well described by a relation proposed for the pressure loss in closed-end tubes. In the region of negligible weir influence values of liquid holdup were again succesfully correlated by the Lockhart-Martinelli relation while the dependence of liquid holdup data on gas and liquid flow rates obtained under conditions of significant weir effect (i.e. at low flow rates of both phases) could be well described by an empirical exponential-type relation. Results of preliminary kLaL measurements confirmed the decisive effect of the rate of energy dissipation on the intensity of interfacial mass transfer in gas-liquid dispersions.

Numerical predictions for laminar source-sink flow in a rotating cylindrical cavity

1984 ◽  
Vol 143 ◽  
pp. 451-466 ◽  
Author(s):  
J. W. Chew ◽  
J. M. Owen ◽  
J. R. Pincombe
Keyword(s):  
Cylindrical Cavity ◽  
Numerical Solutions ◽  
High Flow ◽  
Wall Jet ◽  
Flow Rates ◽  
Numerical Predictions ◽  
Source Sink ◽  
Fresh Insight ◽  
Insight Into ◽  
Good Agreement

Numerical solutions are presented for steady, axisymmetric, laminar, isothermal, source–sink flow in a rotating cylindrical cavity. These results, which are in good agreement with previously published experimental work, have been used to give a fresh insight into the nature of the flow and to investigate the validity of other theoretical solutions. When the fluid enters the cavity through a central uniform radial source and leaves through an outer sink, it is shown that the flow near the disks can be approximated by two known analytical solutions. If the radial source is replaced by an axial inlet the flow becomes more complex, with a wall jet forming on the downstream disk at sufficiently high flow rates.

Low-power micro-fabricated liquid flow-rate sensor

2015 ◽  
Vol 7 (9) ◽  
pp. 3981-3987 ◽  
Author(s):  
Wen-Chi Lin ◽  
Mark A. Burns
Keyword(s):  
Low Power ◽  
Water Flow ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Experimental Results ◽  
Flow Sensors ◽  
Flow Rates ◽  
Rate Sensor ◽  
Good Agreement

We have constructed micro-fabricated flow sensors that can measure water flow rates of 0.1 to 2.0 gallons per minute (GPM), and the experimental results we obtained are in good agreement with those from COMSOL simulations.

scholarly journals Liquid Flow and Mass Transfer Behaviors in a Butterfly-Shaped Microreactor

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 883
Author(s):  
Haicheng Lv ◽  
Zhirong Yang ◽  
Jing Zhang ◽  
Gang Qian ◽  
Xuezhi Duan ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Flow Pattern ◽  
Liquid Flow ◽  
Two Phase Flow ◽  
Flow Behavior ◽  
Dynamics Simulation ◽  
Mixing Efficiency ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Rates

Based on the split-and-recombine principle, a millimeter-scale butterfly-shaped microreactor was designed and fabricated through femtosecond laser micromachining. The velocity fields, streamlines and pressure fields of the single-phase flow in the microreactor were obtained by a computational fluid dynamics simulation, and the influence of flow rates on the homogeneous mixing efficiency was quantified by the mixing index. The flow behaviors in the microreactor were investigated using water and n-butanol, from which schematic diagrams of various flow patterns were given and a flow pattern map was established for regulating the flow behavior via controlling the flow rates of the two-phase flow. Furthermore, effects of the two-phase flow rates on the droplet flow behavior (droplet number, droplet size and standard deviation) in the microreactor were investigated. In addition, the interfacial mass transfer behaviors of liquid–liquid flow were evaluated using the standard low interfacial tension system of “n-butanol/succinic acid/water”, where the dependence between the flow pattern and mass transfer was discussed. The empirical relationship between the volumetric mass transfer coefficient and Reynold number was established with prediction error less than 20%.

Experimental and Numerical Studies of Carbon Black Formation Through Thermal Decomposition of Waste Natural Gas

2008 ◽  
Author(s):  
M. Moghiman ◽  
N. Hosseini ◽  
M. H. Raad ◽  
M. Javadi
Keyword(s):  
Natural Gas ◽  
Carbon Black ◽  
Equivalence Ratio ◽  
Gravimetric Method ◽  
Solid Carbon ◽  
Flow Rates ◽  
Numerical Studies ◽  
Numerical Predictions ◽  
Dominant Process ◽  
Good Agreement

The present study is concerned with measuring and simulating the formation process of carbon black in a natural gas furnace. Carbon black concentrations in the furnace have been measured by the gravimetric method. Fluent CFD software has been employed for numerical predictions. A chemical reaction formulation relates the production of the carbon black to the incomplete combustion and pyrolysis of natural gas as the parent fuel. The influences of feedstock flow rate and equivalence ratio on carbon black furnace output are investigated. The results show that for relatively low feedstock flow rates, most feedstock hydrocarbon burns to CO, while for higher feedstock flow rates the decomposition of feedstock and formation of solid carbon is the dominant process and has an important role in the production of carbon black. The comparison of calculated results against the experimental measurements shows good agreement.

First Attempt on Numerical Prediction of Cavitation Damage on a Centrifugal Pump

2017 ◽  
Author(s):  
Christophe Leclercq ◽  
Regiane Fortes-Patella ◽  
Antoine Archer ◽  
Fabien Cerru
Keyword(s):  
Centrifugal Pump ◽  
Cavitating Flow ◽  
Homogeneous Fluid ◽  
Cavitation Damage ◽  
Flow Simulations ◽  
Numerical Predictions ◽  
Hydraulic Machines ◽  
Cavitation Intensity ◽  
Good Agreement ◽  
Unsteady Cavitating Flow

The cavitation erosion remains an industrial issue for many applications, mainly for hydraulic machines. This paper deals with the cavitation intensity, which can be described as the fluid mechanical loading causing cavitation damage. The estimation of this intensity is a challenging problem both in terms of modeling the cavitating flow and predicting the erosion due to cavitation. For this purpose, a numerical methodology was proposed to estimate cavitation intensity from 3D unsteady cavitating flow simulations. CFD calculations were carried out using Code_Saturne, which solves U-RANS equations for a homogeneous fluid using the Merkle’s model [1], coupled to a k-ε turbulence model with the Reboud’s correction. A cavitation intensity prediction model was developped based on pressure and void fraction derivatives obtained through CFD calculations. It was previously applied to study cavitation damage [2] on a NACA65012 hydrofoil. The article briefly presents this validation case as well as the prediction of the cavitation intensity on the blades of a centrifugal pump called “SHF pump” and tested at EDF R&D laboratory [3]. The numerical predictions of cavitation damage are in good agreement with experimental results obtained by pitting.

Upward Vertical Two-Phase Flow Through an Annulus—Part II: Modeling Bubble, Slug, and Annular Flow

1992 ◽  
Vol 114 (1) ◽  
pp. 14-30 ◽  
Author(s):  
E. F. Caetano ◽  
O. Shoham ◽  
J. P. Brill
Keyword(s):  
Flow Pattern ◽  
Annular Flow ◽  
Two Phase Flow ◽  
Flow Behavior ◽  
Bubble Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Through ◽  
Physical Phenomena ◽  
Good Agreement

Mechanistic models have been developed for each of the existing two-phase flow patterns in an annulus, namely bubble flow, dispersed bubble flow, slug flow, and annular flow. These models are based on two-phase flow physical phenomena and incorporate annulus characteristics such as casing and tubing diameters and degree of eccentricity. The models also apply the new predictive means for friction factor and Taylor bubble rise velocity presented in Part I. Given a set of flow conditions, the existing flow pattern in the system can be predicted. The developed models are applied next for predicting the flow behavior, including the average volumetric liquid holdup and the average total pressure gradient for the existing flow pattern. In general, good agreement was observed between the experimental data and model predictions.

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