Publicado 12 números por año
ISSN Imprimir: 1044-5110
ISSN En Línea: 1936-2684
Indexed in
NUMERICAL MODELS FOR SIMULATION OF CAVITATION IN DIESEL INJECTOR NOZZLES
SINOPSIS
This paper examines the applicability of the following three different combinations of cavitation models to simulate cavitating flows in a nozzle of liquid fuel injector for diesel engines. The first model in a house code consists of the Lagrangian bubble tracking method (BTM), the Rayleigh-Plesset (RP) equation, and large eddy simulation (LES). The second model is the combination of the homogeneous equilibrium model (HEM), a barotropic (Baro) equation, and the RANS turbulence model (k-ω SST). The last one utilizes HEM, RANS (k-ε, k-ω SST), and the mass transfer model (MTM), in which bubble dynamics is calculated by the simplified RP equation. OpenFOAM is used for the simulations with the second and third models. Unsteady cavitation in a rectangular injector nozzle is captured by a high-speed camera and the turbulent velocity in the nozzle is measured by laser Doppler velocimetry (LDV); they are compared with the numerical results. As a result, the following conclusions are obtained. The BTM/RP/LES model gives a good prediction for the cavitation length and thickness, as well as cavitation cloud shedding. However, it requires a fine grid and a long CPU time, and is applicable only to incipient cavitation. The HEM/Baro/RANS approach results in a wrong prediction for cavitation length and thickness, and underestimation of the turbulence velocity. It cannot reproduce unsteady cavitation behavior. The combination of HEM/MTM/RANS gives good prediction for the cavitation length and thickness with a relatively coarse grid, and therefore with a short CPU time.
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Tahmasebi Ehsanallah, Lucchini Tommaso, D’Errico Gianluca, Onorati Angelo, Hardy Gilles, An investigation of the validity of a homogeneous equilibrium model for different diesel injector nozzles and flow conditions, Energy Conversion and Management, 154, 2017. Crossref
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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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Coussirat M., Moll F., Recalibration of Eddy Viscosity Models for Numerical Simulation of Cavitating Flow Patterns in Low Pressure Nozzle Injectors, Journal of Fluids Engineering, 143, 3, 2021. Crossref
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Brunhart Maxwell, Soteriou Celia, Gavaises Manolis, Karathanassis Ioannis, Koukouvinis Phoevos, Jahangir Saad, Poelma Christian, Investigation of cavitation and vapor shedding mechanisms in a Venturi nozzle, Physics of Fluids, 32, 8, 2020. Crossref