Abstract
This paper presents a numerical and qualitative study on the expected hydro-dynamic load-reducing effect of bubbly media near a volumetrically oscillating bubble. In this study, the bubble or bubble cloud is assumed to be spherically symmetric, and its motion is analyzed as a one-dimensional compressible two-phase flow in the radial direction in spherical coordinates. We adopted the CCUP (CIP-Combined Unified Procedure) method, which is a unified analysis method for both compressible and incompressible fluids proposed by Yabe et al. (1991) in order to treat interaction among gas, liquid, and two-phase media, and to avoid large numerical dissipation at density discontinuities. To verify the analysis program we developed, we analyzed free oscillations of a bubble with a unity void fraction and of a bubble cloud with an initial void fraction of 0.5, and found that the natural frequency from numerical results are well reproduced with an error of 0.9% for the bubble and 5% for the bubble cloud as compared to those obtained on a theoretical basis. Using this method, we analyzed the free oscillation of a bubble cloud in which a bubble with a unity void fraction is covered by a bubbly media layer with an initial void fraction of 0.5. Numerical results show that the amplitude of pressure oscillation inside the bubble is about halved, and that a higher mode of oscillation appears when a bubbly media layer covers the bubble. The measured results from a blowdown test we previously reported also shows a similar higher mode of oscillation. The amplitude of pressure oscillation in the water region was apparently reduced when a thick bubbly media layer covers the bubble. Thus, if the bubbly media is ejected from sparger holes prior to the ejection of a high-pressure bubble, the bubbly media might reduce the hydrodynamic load induced in a water pool made by volumetric oscillation of the bubble.
| Original language | English |
|---|---|
| Title of host publication | Proceedings of 2006 ASME Pressure Vessels and Piping Division Conference - ASME PVP2006/ICPVT-11 Conference - Pressure Vessel Technologies for the Global Community |
| Volume | 2006 |
| DOIs | |
| Publication status | Published - 2006 Nov 29 |
| Externally published | Yes |
| Event | ASME PVP2006/ICPVT-11 Conference - Vancouver, BC, Canada Duration: 2006 Jul 23 → 2006 Jul 27 |
Other
| Other | ASME PVP2006/ICPVT-11 Conference |
|---|---|
| Country | Canada |
| City | Vancouver, BC |
| Period | 06/7/23 → 06/7/27 |
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Keywords
- Bubble cloud
- CCUP method
- Dynamic load
- Pressure oscillation
- SRV
ASJC Scopus subject areas
- Mechanical Engineering
- Industrial and Manufacturing Engineering
Cite this
A study on the hydrodynamic load in a water pool when discharged air forms a bubble cloud. / Uchida, Ken; Suzuki, Seijiro.
Proceedings of 2006 ASME Pressure Vessels and Piping Division Conference - ASME PVP2006/ICPVT-11 Conference - Pressure Vessel Technologies for the Global Community. Vol. 2006 2006.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - A study on the hydrodynamic load in a water pool when discharged air forms a bubble cloud
AU - Uchida, Ken
AU - Suzuki, Seijiro
PY - 2006/11/29
Y1 - 2006/11/29
N2 - This paper presents a numerical and qualitative study on the expected hydro-dynamic load-reducing effect of bubbly media near a volumetrically oscillating bubble. In this study, the bubble or bubble cloud is assumed to be spherically symmetric, and its motion is analyzed as a one-dimensional compressible two-phase flow in the radial direction in spherical coordinates. We adopted the CCUP (CIP-Combined Unified Procedure) method, which is a unified analysis method for both compressible and incompressible fluids proposed by Yabe et al. (1991) in order to treat interaction among gas, liquid, and two-phase media, and to avoid large numerical dissipation at density discontinuities. To verify the analysis program we developed, we analyzed free oscillations of a bubble with a unity void fraction and of a bubble cloud with an initial void fraction of 0.5, and found that the natural frequency from numerical results are well reproduced with an error of 0.9% for the bubble and 5% for the bubble cloud as compared to those obtained on a theoretical basis. Using this method, we analyzed the free oscillation of a bubble cloud in which a bubble with a unity void fraction is covered by a bubbly media layer with an initial void fraction of 0.5. Numerical results show that the amplitude of pressure oscillation inside the bubble is about halved, and that a higher mode of oscillation appears when a bubbly media layer covers the bubble. The measured results from a blowdown test we previously reported also shows a similar higher mode of oscillation. The amplitude of pressure oscillation in the water region was apparently reduced when a thick bubbly media layer covers the bubble. Thus, if the bubbly media is ejected from sparger holes prior to the ejection of a high-pressure bubble, the bubbly media might reduce the hydrodynamic load induced in a water pool made by volumetric oscillation of the bubble.
AB - This paper presents a numerical and qualitative study on the expected hydro-dynamic load-reducing effect of bubbly media near a volumetrically oscillating bubble. In this study, the bubble or bubble cloud is assumed to be spherically symmetric, and its motion is analyzed as a one-dimensional compressible two-phase flow in the radial direction in spherical coordinates. We adopted the CCUP (CIP-Combined Unified Procedure) method, which is a unified analysis method for both compressible and incompressible fluids proposed by Yabe et al. (1991) in order to treat interaction among gas, liquid, and two-phase media, and to avoid large numerical dissipation at density discontinuities. To verify the analysis program we developed, we analyzed free oscillations of a bubble with a unity void fraction and of a bubble cloud with an initial void fraction of 0.5, and found that the natural frequency from numerical results are well reproduced with an error of 0.9% for the bubble and 5% for the bubble cloud as compared to those obtained on a theoretical basis. Using this method, we analyzed the free oscillation of a bubble cloud in which a bubble with a unity void fraction is covered by a bubbly media layer with an initial void fraction of 0.5. Numerical results show that the amplitude of pressure oscillation inside the bubble is about halved, and that a higher mode of oscillation appears when a bubbly media layer covers the bubble. The measured results from a blowdown test we previously reported also shows a similar higher mode of oscillation. The amplitude of pressure oscillation in the water region was apparently reduced when a thick bubbly media layer covers the bubble. Thus, if the bubbly media is ejected from sparger holes prior to the ejection of a high-pressure bubble, the bubbly media might reduce the hydrodynamic load induced in a water pool made by volumetric oscillation of the bubble.
KW - Bubble cloud
KW - CCUP method
KW - Dynamic load
KW - Pressure oscillation
KW - SRV
UR - http://www.scopus.com/inward/record.url?scp=33751332572&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33751332572&partnerID=8YFLogxK
U2 - 10.1115/PVP2006-ICPVT-11-93281
DO - 10.1115/PVP2006-ICPVT-11-93281
M3 - Conference contribution
AN - SCOPUS:33751332572
SN - 0791837823
SN - 9780791837825
VL - 2006
BT - Proceedings of 2006 ASME Pressure Vessels and Piping Division Conference - ASME PVP2006/ICPVT-11 Conference - Pressure Vessel Technologies for the Global Community
ER -