20.500.12556/DiRROS-18280 Numerical modelling and experimental validation of dripping, jetting and whipping modes of gas dynamic virtual nozzle Purpose – This study aims to develop an experimentally validated three-dimensional numerical model for predicting different flow patterns produced with a gas dynamic virtual nozzle (GDVN). Design/methodology/approach – The physical model is posed in the mixture formulation and copes with the unsteady, incompressible, isothermal, Newtonian, low turbulent two-phase flow. The computational fluid dynamics numerical solution is based on the half-space finite volume discretisation. The geo-reconstruct volume-of-fluid scheme tracks the interphase boundary between the gas and the liquid. To ensure numerical stability in the transition regime and adequately account for turbulent behaviour, the k-v shear stress transport turbulence model is used. The model is validated by comparison with the experimental measurements on a vertical, downward-positioned GDVN configuration. Three different combinations of air and water volumetric flow rates have been solved numerically in the range of Reynolds numbers for airflow 1,009–2,596 and water 61–133, respectively, at Weber numbers 1.2–6.2. Findings – The half-space symmetry allows the numerical reconstruction of the dripping, jetting and indication of the whipping mode. The kinetic energy transfer from the gas to the liquid is analysed, and locations with locally increased gas kinetic energy are observed. The calculated jet shapes reasonably well match the experimentally obtained high-speed camera videos. Practical implications – The model is used for the virtual studies of new GDVN nozzle designs and optimisation of their operation. Originality/value – To the best of the authors’ knowledge, the developed model numerically reconstructs all three GDVN flow regimes for the first time. flow-focusing dripping jetting whipping gas dynamic virtual nozzle CFD fokusiranje toka kapljanje brizganje opletanje plinsko dinamične virtualna šobe računalniška dinamika tekočin true false true Emerald Publishing Limited Anglija Angleški jezik Slovenski jezik © Krištof Kovačič, Jurij Gregorc and Božidar Šarler Neznano 2024-02-28 11:48:56 2024-02-28 11:48:57 2024-12-18 03:55:05 0000-00-00 00:00:00 2024 0 0 str. 1-27 2024 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2024-02-05 532 0961-5539 10.1108/HFF-09-2023-0573 183506435 RAZ_Kovacic_Kristof_2024.pdf RAZ_Kovacic_Kristof_2024.pdf 1 FCA1DD3F1409A2A2634621379D577CDE 9eba9372b977af9e59462f0dc2c5a8b0b931d47f9ab6be042f2afb3d063404a7 1bbb1d58-bc53-11ef-ba3f-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=29736 https://www.emerald.com/insight/content/doi/10.1108/HFF-09-2023-0573/full/html 1 98e4c514-d61e-11ee-900a-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=24828 Inštitut za kovinske materiale in tehnologije 0 0 0