Two-phase countercurrent flow through a bed of packing. V. Correlation of pressure drop over the entire range of gas flow rates and of hold-up at zero flow of gas

1968 ◽  
Vol 33 (11) ◽  
pp. 3870-3876 ◽  
Author(s):  
V. Kolář ◽  
Z. Brož
Keyword(s):  
Pressure Drop ◽  
Entire Range ◽  
Gas Flow ◽  
Countercurrent Flow ◽  
Two Phase ◽  
Flow Rates ◽  
Flow Through ◽  
Zero Flow

Measurements of Two-Phase Pressure Drop in a Simulated Debris Bed

2017 ◽  
Author(s):  
Milka Hebi Nava Rivera ◽  
Daisuke Ito ◽  
Yasushi Saito ◽  
Mitsuhiro Aoyagi ◽  
Kenji Kamiyama ◽  
...  
Keyword(s):  
Porous Media ◽  
Pressure Drop ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Severe Accident ◽  
Phase Flow ◽  
Two Phase ◽  
Experimental Database ◽  
Flow Through ◽  
Measured Pressure

Two-phase flow through porous media should be well understood to develop a severe accident analysis code not only for light water reactor but also sodium cooled fast reactor (SFR). When a core disruptive accident occurs in SFR, the fuel inside the core may become melted and interacts with the coolant. As a result, gas-liquid two-phase flow will be formed in the debris bed, which may have porous nature depending on the cooling process. Thus, as first step, present work focuses on the characteristics of pressure drop in single- and two-phase flows in different porous media conditions (porous size, liquid and gas flow velocity). In addition, in order to construct an experimental database, the measured pressure drop under different conditions was compared with existing correlations.

Predictions of Flow Boiling in Fractal-Like Branching Microchannels

2005 ◽  
Author(s):  
Brian J. Daniels ◽  
Deborah V. Pence ◽  
James A. Liburdy
Keyword(s):  
Pressure Drop ◽  
Single Phase ◽  
Heat Fluxes ◽  
Phase Flow ◽  
Parallel Channel ◽  
Pumping Power ◽  
Flow Networks ◽  
Two Phase ◽  
Flow Rates ◽  
Flow Through

Single-phase and two-phase flows in microscale fractal-like branching flow networks are studied using a one-dimensional model that includes variable property and developing flow effects. Pressure drop, pumping power, changes in the bulk fluid temperature and a performance parameter are reported for mass flow rates ranging from 25 to 500 g/min and wall heat fluxes from 5 to 40 W/cm2. Two-phase flow through fractal-like flow networks is also compared to flow through a series of parallel channels for identical wall heat fluxes and for flow rates between 25 and 100 g/min. Channel length, height, convective surface area, heat flux and flow rate were the same between the fractal-like and parallel channel array. It was found that single-phase flows through fractal-like flow networks exhibit lower pressure drop and pumping power than do two-phase flows at the same wall heat flux and mass flow rate. The inlet temperature for the single-phase cases is 20°C, whereas the two-phase flow enters as a saturated liquid. The pressure drop and pumping power were always lowest for the fractal-like flow networks compared with the parallel channel arrays for identical heat transfer and flow rates.

Pressure Drop for Oil-Gas Two-Phase Flow Through Straight Horizontal Pipe

2007 ◽  
Author(s):  
Wenhong Liu ◽  
Liejin Guo ◽  
Ximin Zhang ◽  
Kai Lin ◽  
Long Yang ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Flow Through ◽  
Oil Gas

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.

Two-Phase Flows in Mini-/Micro-Gas Flow Channels of PEM Fuel Cells

2013 ◽  
Author(s):  
Sung Chan Cho ◽  
Yun Wang
Keyword(s):  
Pressure Drop ◽  
Gas Flow ◽  
Fluid Model ◽  
Pem Fuel Cells ◽  
Two Phase ◽  
Micro Gas Flow ◽  
Two Fluid Model ◽  
The Impact ◽  
Two Fluid ◽  
Phase Pressure

In this paper, two-phase flow dynamics in a micro channel with various wall conditions are both experimentally and theoretically investigated. Annulus, wavy and slug flow patterns are observed and location of liquid phase on different wall condition is visualized. The impact of flow structure on two-phase pressure drop is explained. Two-phase pressure drop is compared to a two-fluid model with relative permeability correlation. Optimization of correlation is conducted for each experimental case and theoretical solution for the flows in a circular channel is developed for annulus flow pattern showing a good match with experimental data in homogeneous channel case.

scholarly journals Pressure drop and average void fraction measurements for two-phase flow through highly permeable porous media

2016 ◽  
Vol 94 ◽  
pp. 422-432 ◽  
Author(s):  
N. Chikhi ◽  
R. Clavier ◽  
J.-P. Laurent ◽  
F. Fichot ◽  
M. Quintard
Keyword(s):  
Porous Media ◽  
Pressure Drop ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Through

Instability Modes of Two-Phase Flows in a Mixing-Layer Microdevice

2001 ◽  
Author(s):  
Tak For Yu ◽  
Sylvanus Yuk Kwan Lee ◽  
Yitshak Zohar ◽  
Man Wong
Keyword(s):  
Gas Flow ◽  
Mixing Layer ◽  
Fluid Flows ◽  
Two Phase Flows ◽  
Two Phase ◽  
Pressure Distributions ◽  
Instability Modes ◽  
In Series ◽  
Mass Flow Rates ◽  
Flow Through

Abstract Extensive development of biomedical and chemical analytic microdevices involves microscale fluid flows. Merging of fluid streams is expected to be a key feature in such devices. An integrated microsystem consisting of merging microchannels and distributed pressure microsensors has been designed and characterized to study this phenomenon on a microscale. The two narrow, uniform and identical channels merged smoothly into a wide, straight and uniform channel downstream of a splitter plate. All of the devices were fabricated using standard micromachining techniques. Mass flow rates and pressure distributions were measured for single-phase gas flow in order to characterize the device. The experimental results indicated that the flow developed when both inlets were connected together to the gas source could be modeled as gas flow through a straight and uniform microchannel. The flow through a single branch while the other was blocked, however, could be modeled as gas flow through a pair of microchannels in series. Flow visualizations of two-phase flows have been conducted when driving liquid and gas through the inlet channels. Several instability modes of the gas/liquid interface have been observed as a function of the pressure difference between the two streams at the merging location.

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