Gas-Liquid Horizontal Flow
José L.H. Faccini and Paulo A.B. SampaioInstituto de Engenharia Nuclear CNEN
Brazil
Jian SuNuclear Engineering Program, COPPEUniversidade Federal do Rio de Janeiro
Brasil
PASI 2007, August 2007, Mar del Plata, Argentina
Collaborators
Prof. Jen-Shih Chang, McMaster
Prof. Glenn Harvel, Univ Ontario Inst Tech
Tatiana Masala, AECL
Dr. Carlos Lamy, IEN/CNEN
Jurandyr Cunha de Souza, COPPE/UFRJ
Gas-liquid two-phase stratified and intermittent horizontal flow using
ultrasonic and high-speed visualization techniques
Two-Phase Flow – Steady State Operation
• Steady state operation of two-phase flow in pipes means that the flow rate of the fluids (gas and liquid) are constant;
• As a result, the conditions at any point in the pipe remains constant: the flow pattern, average void fraction, average pressure drop and average local flow rates do not vary with time;
• two flow seldom is a truly steady state flow and averaging values are used over a time period characteristic of the flow pattern.
Definition of Basic Parameters
T
L
T
G
A
A-1 ,
A
A
T
LsLs
T
GsGs A
Qu ,
A
Qu
1
uu ,
uu Ls
LGs
G
T
Ls
T
Gs
Q
Q-1 ,
Q
Q
Void fraction and liquid holdup
Gas and liquid superficial velocities
Gas and liquid (phase) velocities
Volumetric fraction or nonslip holdup
Experimental Techniques
Technique InterferingSteady
State
Slow transi
ent
Fast Transient
Flow Regime
Local Void fraction
Averaged
Void
fraction
Void fracti
on distributio
n
Phase Velocity
Conductance Yes Yes Yes Yes No Yes No Limited Yes
Capacitance No Yes Yes Yes Yes No Yes Limited Yes
Opticaltechniques
Yes Yes Yes Yes Yes Yes Yes Limited Yes
Gamma ray No Yes Yes NeedStrongSource
Yes No Yes Limited Yes
X-ray No Yes Yes Yes Yes No Yes Yes Yes
NeutronRadiography
No Yes Yes No Yes No Yes Yes Yes
Ultrasonic No Yes Yes Yes Yes Limited Yes Yes Yes
Masala (2004)
Doppler Flowmeter
Doppler ultrasonic flowmeters operate on the Doppler effect, whereby the transmitted frequency is altered linearly by being reflected from particles and bubbles in the fluid. The net result is a frequency shift between transmitter and receiver frequencies that can be directly related to the flow rate.
Ultrasonic Techniques
Dia:12/11/05 Hora:18:01:35
Valores Observações3,949E-5Arquivo escoamento_ST_000.txt3,924E-5Arquivo escoamento_ST_001.txt3,928E-5Arquivo escoamento_ST_002.txt7,444E-5Arquivo escoamento_ST_003.txt3,932E-5Arquivo escoamento_ST_004.txt3,994E-5Arquivo escoamento_ST_005.txt
Ultrasonic System for Two-Phase Flow
CS12100 Card
WinspectSoftware
Motor ControllerDMC 1800
Multiplexer
…
1
42
UG
3
UL
1 2 3 4
Transducers
Transducers
PC
Masala (2004), Masala, Harvel, Su, Chang (2007)
Slug flow
Slug Flow at ULs=0.072 m/s & UGs=1.92 m/s
0
0.4
0.8
1.2
1.6
2
0 0.4 0.8 1.2 1.6 2 2.4 2.8 3.2
Time(sec)
Liqu
id L
evel
(cm
)
0
1
Transducer # 4
Transducer #3
Top of the Tube
Bottom of the tube
Plug flow
Plug Flow at 6ms
0
0.5
1
1.5
2
2.5
0 0.5 1 1.5 2 2.5 3 3.5
Time(s)
Dis
tan
ce
(c
m)
transducer 4
transducer 2