Numerical Determination of the Equivalent Sand Roughness of a Turbopump’s Surface and Its Roughness Influence on the Pump Characteristics
The correct computation of flows over rough surfaces in technical systems, such as in turbomachines, is a significant issue for proper simulations of their performance data. Once the flow over rough surfaces is adequately computed in these machines, simulations become more trustworthy and can replac...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-02-01
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| Series: | International Journal of Turbomachinery, Propulsion and Power |
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| Online Access: | https://www.mdpi.com/2504-186X/8/1/5 |
| _version_ | 1797611142147735552 |
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| author | Benjamin Torner Duc Viet Duong Frank-Hendrik Wurm |
| author_facet | Benjamin Torner Duc Viet Duong Frank-Hendrik Wurm |
| author_sort | Benjamin Torner |
| collection | DOAJ |
| description | The correct computation of flows over rough surfaces in technical systems, such as in turbomachines, is a significant issue for proper simulations of their performance data. Once the flow over rough surfaces is adequately computed in these machines, simulations become more trustworthy and can replace experimental prototyping. Roughness modelling approaches are often implemented in a solver to account for roughness effects in flow simulations. In these approaches, the equivalent sand roughness <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>k</mi><mi>s</mi></msub></semantics></math></inline-formula> must be defined as a characteristic parameter of the rough surface. However, it is difficult to determine the corresponding <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>k</mi><mi>s</mi></msub></semantics></math></inline-formula>-value for a surface roughness. In this context, this paper shows a novel and time-efficient numerical method, the discrete porosity method (DPM), which can be used to determine the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>k</mi><mi>s</mi></msub></semantics></math></inline-formula>-value of a rough surface. Applying this method, channel flow simulations were performed with an irregularly distributed cast iron surface from a turbopumps volute. After identifying the fully rough regime, the equivalent sand roughness was determined and a match with <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>k</mi><mi>s</mi></msub></semantics></math></inline-formula>-values from literature data was found. Subsequently, the established <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>k</mi><mi>s</mi></msub></semantics></math></inline-formula>-value for cast iron was used in a turbopump simulation with rough walls. The performance data of the pump were validated by experiments and a good agreement between the experimental and simulated performance data was found. |
| first_indexed | 2024-03-11T06:24:37Z |
| format | Article |
| id | doaj.art-f7f87e5392bf4d0f8cdf3f5319889508 |
| institution | Directory Open Access Journal |
| issn | 2504-186X |
| language | English |
| last_indexed | 2024-03-11T06:24:37Z |
| publishDate | 2023-02-01 |
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| series | International Journal of Turbomachinery, Propulsion and Power |
| spelling | doaj.art-f7f87e5392bf4d0f8cdf3f53198895082023-11-17T11:43:03ZengMDPI AGInternational Journal of Turbomachinery, Propulsion and Power2504-186X2023-02-0181510.3390/ijtpp8010005Numerical Determination of the Equivalent Sand Roughness of a Turbopump’s Surface and Its Roughness Influence on the Pump CharacteristicsBenjamin Torner0Duc Viet Duong1Frank-Hendrik Wurm2Institute of Turbomachinery, University of Rostock, Albert-Einstein Str. 2, 18059 Rostock, GermanyInstitute of Turbomachinery, University of Rostock, Albert-Einstein Str. 2, 18059 Rostock, GermanyInstitute of Turbomachinery, University of Rostock, Albert-Einstein Str. 2, 18059 Rostock, GermanyThe correct computation of flows over rough surfaces in technical systems, such as in turbomachines, is a significant issue for proper simulations of their performance data. Once the flow over rough surfaces is adequately computed in these machines, simulations become more trustworthy and can replace experimental prototyping. Roughness modelling approaches are often implemented in a solver to account for roughness effects in flow simulations. In these approaches, the equivalent sand roughness <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>k</mi><mi>s</mi></msub></semantics></math></inline-formula> must be defined as a characteristic parameter of the rough surface. However, it is difficult to determine the corresponding <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>k</mi><mi>s</mi></msub></semantics></math></inline-formula>-value for a surface roughness. In this context, this paper shows a novel and time-efficient numerical method, the discrete porosity method (DPM), which can be used to determine the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>k</mi><mi>s</mi></msub></semantics></math></inline-formula>-value of a rough surface. Applying this method, channel flow simulations were performed with an irregularly distributed cast iron surface from a turbopumps volute. After identifying the fully rough regime, the equivalent sand roughness was determined and a match with <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>k</mi><mi>s</mi></msub></semantics></math></inline-formula>-values from literature data was found. Subsequently, the established <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>k</mi><mi>s</mi></msub></semantics></math></inline-formula>-value for cast iron was used in a turbopump simulation with rough walls. The performance data of the pump were validated by experiments and a good agreement between the experimental and simulated performance data was found.https://www.mdpi.com/2504-186X/8/1/5roughness modellingequivalent sand grain roughnessdiscrete porosity methodturbopumpcast iron roughness |
| spellingShingle | Benjamin Torner Duc Viet Duong Frank-Hendrik Wurm Numerical Determination of the Equivalent Sand Roughness of a Turbopump’s Surface and Its Roughness Influence on the Pump Characteristics International Journal of Turbomachinery, Propulsion and Power roughness modelling equivalent sand grain roughness discrete porosity method turbopump cast iron roughness |
| title | Numerical Determination of the Equivalent Sand Roughness of a Turbopump’s Surface and Its Roughness Influence on the Pump Characteristics |
| title_full | Numerical Determination of the Equivalent Sand Roughness of a Turbopump’s Surface and Its Roughness Influence on the Pump Characteristics |
| title_fullStr | Numerical Determination of the Equivalent Sand Roughness of a Turbopump’s Surface and Its Roughness Influence on the Pump Characteristics |
| title_full_unstemmed | Numerical Determination of the Equivalent Sand Roughness of a Turbopump’s Surface and Its Roughness Influence on the Pump Characteristics |
| title_short | Numerical Determination of the Equivalent Sand Roughness of a Turbopump’s Surface and Its Roughness Influence on the Pump Characteristics |
| title_sort | numerical determination of the equivalent sand roughness of a turbopump s surface and its roughness influence on the pump characteristics |
| topic | roughness modelling equivalent sand grain roughness discrete porosity method turbopump cast iron roughness |
| url | https://www.mdpi.com/2504-186X/8/1/5 |
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