每年出版 12 期
ISSN 打印: 1044-5110
ISSN 在线: 1936-2684
Indexed in
LARGE EDDY SIMULATIONS OF CAVITATING FLOW IN A STEP NOZZLE WITH INJECTION INTO GAS
摘要
We present results of large eddy simulations of a cavitating nozzle flow and injection into gas, investigating the interactions of cavitation in the nozzle, primary jet breakup, mass-flow rates, and gas entrainment. During strong cavitation, detached vapor structures can reach the nozzle outlet, leading to partial entrainment of gas from the outflow region into the nozzle. The gas entrainment
can affect cavitation dynamics, mass-flow rates, and jet breakup.Moreover, the implosion of detached vapor structures induces pressure peaks that on the one hand amplify turbulent fluctuations and subsequently can enhance jet breakup and on the other hand can damage walls in the proximity and thus lead to cavitation erosion.
Our numerical setup is based on a reference experiment, in which liquid water is discharged into ambient air through a step nozzle. The cavitating liquid and the noncondensable gas phase are modeled with a barotropic homogeneous mixture model while for the numerical model a high-order implicit
large eddy approach is employed. Full compressibility of all components is taken into account, enabling us to capture the effects of collapsing vapor structures. Two operating points covering different cavitation regimes and jet characteristics are investigated. Special emphasis is placed on studying the effects of cavitation on the mass flow and the jet as well as the impact of partial gas entrainment.
Therefore, frequency analyses of the recorded time-resolved signals are performed. Furthermore, the dynamics and intensities of imploding vapor structures are assessed.
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Trummler Theresa, Schmidt Steffen J., Adams Nikolaus A., Investigation of condensation shocks and re-entrant jet dynamics in a cavitating nozzle flow by Large-Eddy Simulation, International Journal of Multiphase Flow, 125, 2020. Crossref
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Bontitsopoulos Stavros, Hamzehloo Arash, Aleiferis Pavlos, Cracknell Roger, Numerical Simulations of the Effect of Cold Fuel Temperature on In-Nozzle Flow and Cavitation Using a Model Injector Geometry, SAE Technical Paper Series, 1, 2020. Crossref
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Ahmed A., Duret B., Reveillon J., Demoulin F.X., Numerical simulation of cavitation for liquid injection in non-condensable gas, International Journal of Multiphase Flow, 127, 2020. Crossref
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Trummler Theresa, Schmidt Steffen J., Adams Nikolaus A., Effect of stand-off distance and spatial resolution on the pressure impact of near-wall vapor bubble collapses, International Journal of Multiphase Flow, 141, 2021. Crossref
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Trummler T., Schmidt S. J., Adams N. A., Numerical investigation of non-condensable gas effect on vapor bubble collapse, Physics of Fluids, 33, 9, 2021. Crossref
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Mishra Rohit, Jiwani Daniel, Jarrahbashi Dorrin, Three-component multi-fluid modeling of pseudo-cavitation phenomenon in diesel injector nozzles, International Journal of Engine Research, 23, 4, 2022. Crossref
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McGinn P., Tretola G., Vogiatzaki K., Unified modeling of cavitating sprays using a three-component volume of fluid method accounting for phase change and phase miscibility, Physics of Fluids, 34, 8, 2022. Crossref