Abstr:AC3-12: Difference between revisions
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and turbulence becomes of importance which strongly depends on particle | and turbulence becomes of importance which strongly depends on particle | ||
size. In order to provide a detailed set of data for validating | size. In order to provide a detailed set of data for validating | ||
numerical simulations thorough measurements by Phase-Doppler-Anemometry | numerical simulations, thorough measurements by Phase-Doppler-Anemometry | ||
were conducted in a laboratory-scale swirling flow system. The test | were conducted in a laboratory-scale swirling flow system. The test | ||
section is a pipe-expansion flow with a co-annular inlet (diameter 64 | section is a pipe-expansion flow with a co-annular inlet (diameter 64 | ||
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particle counts) are available whereby the size segregation could be | particle counts) are available whereby the size segregation could be | ||
analysed. From the size-velocity correlations also the mean velocities | analysed. From the size-velocity correlations also the mean velocities | ||
for three size classes were determined, namely 30, 45 and 60 | for three size classes were determined, namely 30, 45 and 60 μm. | ||
Additionally, profiles of the stream-wise particle mass flux were | Additionally, profiles of the stream-wise particle mass flux were | ||
determined. Two swirl cases were considered, which have about the same | determined. Two swirl cases were considered, which have about the same | ||
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Numerical computations performed for the two cases with the in-house | Numerical computations performed for the two cases with the in-house | ||
finite-volume code FASTEST in connection with the k-ε turbulence model | finite-volume code FASTEST in connection with the k-ε turbulence model | ||
showed | showed reasonably good agreement with the measurements. The particle | ||
phase was simulated by Lagrangian tracking also yielding a quite good | phase was simulated by Lagrangian tracking, also yielding a quite good | ||
agreement with measured velocity profiles, the particle mass flux and | agreement with measured velocity profiles, the particle mass flux and | ||
the number mean particle diameter (Sommerfeld and Qiu 1993). | the number mean particle diameter ([[References_AC3-12#11|Sommerfeld and Qiu 1993]]). | ||
The swirling Case 1 was also used as a test case for validating "in- | The swirling Case 1 was also used as a test case for validating "in- | ||
house" codes at the 5th Workshop on Two Phase Flow Predictions | house" codes at the 5th Workshop on Two Phase Flow Predictions | ||
(Sommerfeld and Wennerberg 1991). Several groups have participated in | ([[References_AC3-12#9|Sommerfeld and Wennerberg 1991]]). Several groups have participated in | ||
these calculations and the results may be found in the Workshop | these calculations and the results may be found in the Workshop | ||
Proceedings, including a description of the numerical methods applied. | Proceedings, including a description of the numerical methods applied. | ||
A brief summary of the results is also presented at the end of this | A brief summary of the results is also presented at the end of this | ||
document. As to be expected the scatter of the results from the | document. As was to be expected, the scatter of the results from the | ||
different groups is not negligible. | different groups is not negligible. | ||
<br/> | <br/> | ||
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{{ACContribs | {{ACContribs | ||
|authors=Martin Sommerfeld | |authors=Martin Sommerfeld | ||
|organisation=Martin-Luther- | |organisation=Martin-Luther-Universität Halle-Wittenberg | ||
}} | }} | ||
{{ | {{ACHeader_ref | ||
|area=3 | |area=3 | ||
|number=12 | |number=12 | ||
Latest revision as of 16:25, 11 February 2017
Particle-laden swirling flow
Application Area 3: Chemical, Process, Thermal and Nuclear Safety
Application Challenge AC3-12
Abstract
Swirling particle laden flows are found in various areas of process technology, e.g. swirl burners, pneumatic conveying in swirling pipe flow and gas cyclones. Already the single-phase flow is very complex due to the involved different scales of vortices, the strong anisotropy of turbulence and the mostly observed unsteadiness. In particle-laden swirling flows additionally the particle response to flow structures and turbulence becomes of importance which strongly depends on particle size. In order to provide a detailed set of data for validating numerical simulations, thorough measurements by Phase-Doppler-Anemometry were conducted in a laboratory-scale swirling flow system. The test section is a pipe-expansion flow with a co-annular inlet (diameter 64 mm) and a measurement section of 1500 mm length and a pipe diameter of 194 mm. Linear profiles of all velocity components of gas and particle phase were measured downstream of the inlet at 8 cross-sections between 3 mm and 315 mm. For the particle-phase also local size distributions were measured as well as the size-velocity correlations. Therefore, profiles of the number mean particle diameter (mean diameter based on particle counts) are available whereby the size segregation could be analysed. From the size-velocity correlations also the mean velocities for three size classes were determined, namely 30, 45 and 60 μm. Additionally, profiles of the stream-wise particle mass flux were determined. Two swirl cases were considered, which have about the same swirl number (i.e. about 0.5), but the ratio of secondary mass flow rate to primary mass flow rate was about twice in the second case. The particle mass flow rate was relatively low in both cases, so that the influence of the particles on the gas flow (i.e. two-way coupling) was relatively small.
Numerical computations performed for the two cases with the in-house finite-volume code FASTEST in connection with the k-ε turbulence model showed reasonably good agreement with the measurements. The particle phase was simulated by Lagrangian tracking, also yielding a quite good agreement with measured velocity profiles, the particle mass flux and the number mean particle diameter (Sommerfeld and Qiu 1993).
The swirling Case 1 was also used as a test case for validating "in-
house" codes at the 5th Workshop on Two Phase Flow Predictions
(Sommerfeld and Wennerberg 1991). Several groups have participated in
these calculations and the results may be found in the Workshop
Proceedings, including a description of the numerical methods applied.
A brief summary of the results is also presented at the end of this
document. As was to be expected, the scatter of the results from the
different groups is not negligible.
Contributed by: Martin Sommerfeld — Martin-Luther-Universität Halle-Wittenberg
© copyright ERCOFTAC 2013