Using Computation Fluid Dynamics to Determine Oil Droplet Breakup Parameters during Emulsion Atomization with Pressure Swirl Nozzles
A wide range of commercial powdered products are manufactured by spray drying emulsions. Some product properties are dependent on the oil droplet size, which can be affected by fluid mechanics inside the spray nozzle. However, most of the key flow parameters inside the nozzles are difficult to measu...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-10-01
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| Series: | Fluids |
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| Online Access: | https://www.mdpi.com/2311-5521/8/10/277 |
| _version_ | 1797573835571068928 |
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| author | Miguel Ángel Ballesteros Martínez Volker Gaukel |
| author_facet | Miguel Ángel Ballesteros Martínez Volker Gaukel |
| author_sort | Miguel Ángel Ballesteros Martínez |
| collection | DOAJ |
| description | A wide range of commercial powdered products are manufactured by spray drying emulsions. Some product properties are dependent on the oil droplet size, which can be affected by fluid mechanics inside the spray nozzle. However, most of the key flow parameters inside the nozzles are difficult to measure experimentally, and theoretical estimations present deviations at high shear rates and viscosities. Therefore, the purpose of this study was to develop a computational model that could represent the multiphase flow in pressure swirl nozzles and could determine the deformation stresses and residence times that oil droplets experience. The multiphase flow was modelled using the Volume-of-Fluid method under a laminar regime. The model was validated with experimental data using the operating conditions and the spray angle. The numerically calculated shear stresses were found to provide a better prediction of the final oil droplet size than previous theoretical estimations. A two-step breakup mechanism inside of the nozzle was also proposed. Additionally, some of the assumptions used in the theoretical estimations could not be confirmed for the nozzles investigated: No complete air core developed inside of the nozzle during atomization, and the shear stress at the nozzle outlet is not the only stress that can affect oil droplet size. Elongation stresses cannot be neglected in all cases. |
| first_indexed | 2024-03-10T21:15:41Z |
| format | Article |
| id | doaj.art-635fbef4e9704365aa770251e53b928d |
| institution | Directory Open Access Journal |
| issn | 2311-5521 |
| language | English |
| last_indexed | 2024-03-10T21:15:41Z |
| publishDate | 2023-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fluids |
| spelling | doaj.art-635fbef4e9704365aa770251e53b928d2023-11-19T16:28:36ZengMDPI AGFluids2311-55212023-10-0181027710.3390/fluids8100277Using Computation Fluid Dynamics to Determine Oil Droplet Breakup Parameters during Emulsion Atomization with Pressure Swirl NozzlesMiguel Ángel Ballesteros Martínez0Volker Gaukel1Institute of Process Engineering in Life Sciences: Food Process Engineering, Karlsruhe Institute of Technology, Kaiserstraße 12, 76131 Karlsruhe, GermanyInstitute of Process Engineering in Life Sciences: Food Process Engineering, Karlsruhe Institute of Technology, Kaiserstraße 12, 76131 Karlsruhe, GermanyA wide range of commercial powdered products are manufactured by spray drying emulsions. Some product properties are dependent on the oil droplet size, which can be affected by fluid mechanics inside the spray nozzle. However, most of the key flow parameters inside the nozzles are difficult to measure experimentally, and theoretical estimations present deviations at high shear rates and viscosities. Therefore, the purpose of this study was to develop a computational model that could represent the multiphase flow in pressure swirl nozzles and could determine the deformation stresses and residence times that oil droplets experience. The multiphase flow was modelled using the Volume-of-Fluid method under a laminar regime. The model was validated with experimental data using the operating conditions and the spray angle. The numerically calculated shear stresses were found to provide a better prediction of the final oil droplet size than previous theoretical estimations. A two-step breakup mechanism inside of the nozzle was also proposed. Additionally, some of the assumptions used in the theoretical estimations could not be confirmed for the nozzles investigated: No complete air core developed inside of the nozzle during atomization, and the shear stress at the nozzle outlet is not the only stress that can affect oil droplet size. Elongation stresses cannot be neglected in all cases.https://www.mdpi.com/2311-5521/8/10/277spray dryingstress historydroplet breakupCFDemulsion atomizationpressure swirl spray |
| spellingShingle | Miguel Ángel Ballesteros Martínez Volker Gaukel Using Computation Fluid Dynamics to Determine Oil Droplet Breakup Parameters during Emulsion Atomization with Pressure Swirl Nozzles Fluids spray drying stress history droplet breakup CFD emulsion atomization pressure swirl spray |
| title | Using Computation Fluid Dynamics to Determine Oil Droplet Breakup Parameters during Emulsion Atomization with Pressure Swirl Nozzles |
| title_full | Using Computation Fluid Dynamics to Determine Oil Droplet Breakup Parameters during Emulsion Atomization with Pressure Swirl Nozzles |
| title_fullStr | Using Computation Fluid Dynamics to Determine Oil Droplet Breakup Parameters during Emulsion Atomization with Pressure Swirl Nozzles |
| title_full_unstemmed | Using Computation Fluid Dynamics to Determine Oil Droplet Breakup Parameters during Emulsion Atomization with Pressure Swirl Nozzles |
| title_short | Using Computation Fluid Dynamics to Determine Oil Droplet Breakup Parameters during Emulsion Atomization with Pressure Swirl Nozzles |
| title_sort | using computation fluid dynamics to determine oil droplet breakup parameters during emulsion atomization with pressure swirl nozzles |
| topic | spray drying stress history droplet breakup CFD emulsion atomization pressure swirl spray |
| url | https://www.mdpi.com/2311-5521/8/10/277 |
| work_keys_str_mv | AT miguelangelballesterosmartinez usingcomputationfluiddynamicstodetermineoildropletbreakupparametersduringemulsionatomizationwithpressureswirlnozzles AT volkergaukel usingcomputationfluiddynamicstodetermineoildropletbreakupparametersduringemulsionatomizationwithpressureswirlnozzles |