The Tangential Force Affecting the Radial Baffles in a Stirred Vessel: Analysis of the Macro-instability Related Component
<p>Experimental data obtained by measuring the tangential component of the force affecting radial baffles in a flat-bottomed cylindrical mixing vessel stirred with a Rushton turbine impeller is analysed. Spectral analysis of the experimental data demonstrated the presence of its macro-instabil...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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CTU Central Library
2003-01-01
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| Series: | Acta Polytechnica |
| Subjects: | |
| Online Access: | https://ojs.cvut.cz/ojs/index.php/ap/article/view/450 |
| _version_ | 1811309031680114688 |
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| author | P. Hasal I. Fořt J. Kratěna |
| author_facet | P. Hasal I. Fořt J. Kratěna |
| author_sort | P. Hasal |
| collection | DOAJ |
| description | <p>Experimental data obtained by measuring the tangential component of the force affecting radial baffles in a flat-bottomed cylindrical mixing vessel stirred with a Rushton turbine impeller is analysed. Spectral analysis of the experimental data demonstrated the presence of its macro-instability (MI) related low-frequency component embedded in the total force. Two distinct dimensionless frequencies (both directly proportional to the impeller speed of rotation N) of the occurence of the MI component were detected: a lower frequency of approximately 0.025N and a higher frequency of about 0.085N. The relative magnitude Q<sub>MI</sub> of the MI-related component of the total tangential force was evaluated by a combination of proper orthogonal decomposition (POD) and spectral analysis. The values of magnitude Q<sub>MI</sub> varied in the interval [rom approximately 0.05 to 0.30. The magnitude Q<sub>MI</sub> takes maximum values at low Reynolds number values (in laminar and transitional regions). In the turbulent region (Re<sub>M</sub> >20000) the Q<sub>MI</sub> value is low and practically constant. The dependence oj the Q<sub>MI</sub> values on vertical position in the vessel is only marginal. The results suggest that the magnitude of the MI component of the force is significantly influenced by the liquid viscosity and density.</p> |
| first_indexed | 2024-04-13T09:35:00Z |
| format | Article |
| id | doaj.art-f48aea3d125741e78e2c64c19d705e79 |
| institution | Directory Open Access Journal |
| issn | 1210-2709 1805-2363 |
| language | English |
| last_indexed | 2024-04-13T09:35:00Z |
| publishDate | 2003-01-01 |
| publisher | CTU Central Library |
| record_format | Article |
| series | Acta Polytechnica |
| spelling | doaj.art-f48aea3d125741e78e2c64c19d705e792022-12-22T02:52:08ZengCTU Central LibraryActa Polytechnica1210-27091805-23632003-01-01434450The Tangential Force Affecting the Radial Baffles in a Stirred Vessel: Analysis of the Macro-instability Related ComponentP. HasalI. FořtJ. Kratěna<p>Experimental data obtained by measuring the tangential component of the force affecting radial baffles in a flat-bottomed cylindrical mixing vessel stirred with a Rushton turbine impeller is analysed. Spectral analysis of the experimental data demonstrated the presence of its macro-instability (MI) related low-frequency component embedded in the total force. Two distinct dimensionless frequencies (both directly proportional to the impeller speed of rotation N) of the occurence of the MI component were detected: a lower frequency of approximately 0.025N and a higher frequency of about 0.085N. The relative magnitude Q<sub>MI</sub> of the MI-related component of the total tangential force was evaluated by a combination of proper orthogonal decomposition (POD) and spectral analysis. The values of magnitude Q<sub>MI</sub> varied in the interval [rom approximately 0.05 to 0.30. The magnitude Q<sub>MI</sub> takes maximum values at low Reynolds number values (in laminar and transitional regions). In the turbulent region (Re<sub>M</sub> >20000) the Q<sub>MI</sub> value is low and practically constant. The dependence oj the Q<sub>MI</sub> values on vertical position in the vessel is only marginal. The results suggest that the magnitude of the MI component of the force is significantly influenced by the liquid viscosity and density.</p>https://ojs.cvut.cz/ojs/index.php/ap/article/view/450stirred vesselbafflestangential forcemacro-instabilityspectral analysisproper orthogonal decomposition |
| spellingShingle | P. Hasal I. Fořt J. Kratěna The Tangential Force Affecting the Radial Baffles in a Stirred Vessel: Analysis of the Macro-instability Related Component Acta Polytechnica stirred vessel baffles tangential force macro-instability spectral analysis proper orthogonal decomposition |
| title | The Tangential Force Affecting the Radial Baffles in a Stirred Vessel: Analysis of the Macro-instability Related Component |
| title_full | The Tangential Force Affecting the Radial Baffles in a Stirred Vessel: Analysis of the Macro-instability Related Component |
| title_fullStr | The Tangential Force Affecting the Radial Baffles in a Stirred Vessel: Analysis of the Macro-instability Related Component |
| title_full_unstemmed | The Tangential Force Affecting the Radial Baffles in a Stirred Vessel: Analysis of the Macro-instability Related Component |
| title_short | The Tangential Force Affecting the Radial Baffles in a Stirred Vessel: Analysis of the Macro-instability Related Component |
| title_sort | tangential force affecting the radial baffles in a stirred vessel analysis of the macro instability related component |
| topic | stirred vessel baffles tangential force macro-instability spectral analysis proper orthogonal decomposition |
| url | https://ojs.cvut.cz/ojs/index.php/ap/article/view/450 |
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