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| Titel |
Toward modeling of supercritical CO2 flow using the one-dimensional turbulence model |
| VerfasserIn |
F. T. Schulz, C. Glawe, H. Schmidt, A. R. Kerstein |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250066545
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| Zusammenfassung |
| Within the CCS (Carbon Capture and Storage) technology the transport of captured CO2 is
increasingly regarded as the missing link in research. For industrial applications it is essential
to transport CO2 from power plants to geological sites through pipelines and well bores. The
effectiveness of such a transport could be increased by keeping CO2 in a supercritical state.
This however requires a temperature of at least 31Celsius and a pressure above
73.8 bar. If these conditions are not maintained throughout the whole pipeline,
which is challenging and expensive under non-laboratory conditions, density and
phase changes and pressure fluctuations may result in harmful vibrations of the
pipelines.
Typically, simulations of pipeline flow are based on large-eddy simulations (LES) or the
Reynolds averaged Navier-Stokes (RANS) equations which both do not resolve the smallest
turbulent scales or even phase boundaries. Due to the effect that on pipe diameter scales the
flow statistically changes predominantly in the wall normal direction one might consider 1D
modeling approaches.
The work presented here is part of the GeoEn II activities funded by the Federal Ministry of
Education and Research (BMBF) to better understand risks and benefits of CCS technology.
Our project goal is to better understand the small scale physics in turbulent CO2 flows and to
improve subgrid-scale models used in LES codes.
To achieve this we use ODT (One-Dimensional Turbulence), a statistical turbulence modeling
strategy, where turbulent flow evolution along a notional 1D line of sight is emulated by
applying instantaneous maps to represent the effect of individual turbulent eddies on
property profiles along the line. The occurrence of an eddy itself is affected by
the property profiles, resulting in a self-contained flow evolution that obeys the
applicable conservation laws. Using a 1D ansatz permits a higher resolution of boundary
and single phase density gradients which is key to understand the local CO2 pipe
flow.
Additionally, a level set technique can be used to track phase boundaries along the line of
sight through a multi phase flow. Thus, artificial numerical smearing of the phase
boundaries can be avoided. The ODT process can then move, create, and annihilate such
interfaces.
On the poster we illustrate some milestones to be reached to contribute to a better
understanding of the small scale CO2 pipe flow problem. First ODT is validated and
calibrated against a turbulent channel flow DNS at ReÏ = 590 from Moser [1]. Second the
evolution of turbulence statistics from a liquid jet experiment [2] is compared to ODT
results. Concerning the single supercritical phase we give illustrative examples on how
expectable temperature (density) changes in the pipe influence the turbulence [3].
Note that the numerical frame work presented here is not restricted to CO2 flows. The
milestones and test cases already indicate other technical applications.
References
[1]   R.D. Moser, J. Kim, M.N. N., Direct numerical simulation of turbulent
channel flow up to ReÏ = 590, Physics of Fluids Vol. 11, No. 4, 943 (1999)
[2]   A. Mansour, N. Chigier, Turbulence characteristics in cylindrical liquid jets,
Physics of Fluids 6 (10), 3380 (1994)
[3]   H. Schmidt, A.R. Kerstein, R. Nédélec, S. Wunsch, B.J. Sayler, Numerical
study of radiatively induced entrainment, J. Phys.: Conf. Ser. 318 072017 (2011) |
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