Numerical Assessment of a Two-Phase Model for Propulsive Pump Performance Prediction
The present work provides a detailed numerical investigation of a turbopump for waterjet applications in cavitating conditions. In particular, the study focuses on the complexities of cavitation modelling, serving as a pivotal reference for future computational research, especially in off-design hyd...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-09-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/16/18/6592 |
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| author | Filippo Avanzi Alberto Baù Francesco De Vanna Ernesto Benini |
| author_facet | Filippo Avanzi Alberto Baù Francesco De Vanna Ernesto Benini |
| author_sort | Filippo Avanzi |
| collection | DOAJ |
| description | The present work provides a detailed numerical investigation of a turbopump for waterjet applications in cavitating conditions. In particular, the study focuses on the complexities of cavitation modelling, serving as a pivotal reference for future computational research, especially in off-design hydro-jet scenarios, and it aims to extend current model assessments of the existing methods, by disputing their standard formulations. Thus, a computational domain of a single rotor-stator blade passage is solved using steady-state Reynolds-Averaged Navier–Stokes equations, coupled with one-, two-, and four-equation turbulence models, and compared with available measurements, encompassing both nominal and thrust breakdown conditions. Through grid dependency analysis, a medium refinement with the Shear Stress Transport turbulence model is chosen as the optimal configuration, reducing either computational time and relative error in breakdown efficiency to 1%. This arrangement is coupled with a systematic study of the Zwart cavitation model parameters through multipliers ranging from <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mrow><mo>−</mo><mn>2</mn></mrow></msup></semantics></math></inline-formula> to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mn>2</mn></msup></semantics></math></inline-formula>. Results reveal that properly tuning these values allows for a more accurate reconstruction of the initial phases of cavitation up to breakdown. Notably, increasing the nucleation radius reduces the difference between the estimated head rise and experimental values near breakdown, reducing the maximum error by 4%. This variation constrains vapour concentration, promoting cavitation volume extension in the passage. A similar observation occurs when modifying the condensation coefficient, whereas altering the vaporization coefficient yields opposite effects. |
| first_indexed | 2024-03-10T22:48:50Z |
| format | Article |
| id | doaj.art-014b05a4a8d7484aad992128fa0d1c5d |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-10T22:48:50Z |
| publishDate | 2023-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-014b05a4a8d7484aad992128fa0d1c5d2023-11-19T10:27:20ZengMDPI AGEnergies1996-10732023-09-011618659210.3390/en16186592Numerical Assessment of a Two-Phase Model for Propulsive Pump Performance PredictionFilippo Avanzi0Alberto Baù1Francesco De Vanna2Ernesto Benini3Department of Industrial Engineering, Università degli Studi di Padova, 35131 Padova, ItalyDepartment of Industrial Engineering, Università degli Studi di Padova, 35131 Padova, ItalyDepartment of Industrial Engineering, Università degli Studi di Padova, 35131 Padova, ItalyDepartment of Industrial Engineering, Università degli Studi di Padova, 35131 Padova, ItalyThe present work provides a detailed numerical investigation of a turbopump for waterjet applications in cavitating conditions. In particular, the study focuses on the complexities of cavitation modelling, serving as a pivotal reference for future computational research, especially in off-design hydro-jet scenarios, and it aims to extend current model assessments of the existing methods, by disputing their standard formulations. Thus, a computational domain of a single rotor-stator blade passage is solved using steady-state Reynolds-Averaged Navier–Stokes equations, coupled with one-, two-, and four-equation turbulence models, and compared with available measurements, encompassing both nominal and thrust breakdown conditions. Through grid dependency analysis, a medium refinement with the Shear Stress Transport turbulence model is chosen as the optimal configuration, reducing either computational time and relative error in breakdown efficiency to 1%. This arrangement is coupled with a systematic study of the Zwart cavitation model parameters through multipliers ranging from <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mrow><mo>−</mo><mn>2</mn></mrow></msup></semantics></math></inline-formula> to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mn>2</mn></msup></semantics></math></inline-formula>. Results reveal that properly tuning these values allows for a more accurate reconstruction of the initial phases of cavitation up to breakdown. Notably, increasing the nucleation radius reduces the difference between the estimated head rise and experimental values near breakdown, reducing the maximum error by 4%. This variation constrains vapour concentration, promoting cavitation volume extension in the passage. A similar observation occurs when modifying the condensation coefficient, whereas altering the vaporization coefficient yields opposite effects.https://www.mdpi.com/1996-1073/16/18/6592axial-flow pumpwaterjetcavitationtwo-phase flowsturbomachinerycomputational fluid dynamics |
| spellingShingle | Filippo Avanzi Alberto Baù Francesco De Vanna Ernesto Benini Numerical Assessment of a Two-Phase Model for Propulsive Pump Performance Prediction Energies axial-flow pump waterjet cavitation two-phase flows turbomachinery computational fluid dynamics |
| title | Numerical Assessment of a Two-Phase Model for Propulsive Pump Performance Prediction |
| title_full | Numerical Assessment of a Two-Phase Model for Propulsive Pump Performance Prediction |
| title_fullStr | Numerical Assessment of a Two-Phase Model for Propulsive Pump Performance Prediction |
| title_full_unstemmed | Numerical Assessment of a Two-Phase Model for Propulsive Pump Performance Prediction |
| title_short | Numerical Assessment of a Two-Phase Model for Propulsive Pump Performance Prediction |
| title_sort | numerical assessment of a two phase model for propulsive pump performance prediction |
| topic | axial-flow pump waterjet cavitation two-phase flows turbomachinery computational fluid dynamics |
| url | https://www.mdpi.com/1996-1073/16/18/6592 |
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