Numerical Simulation of the Effect of 3D Needle Movement on Cavitation and Spray Formation in a Diesel Injector

9th International Symposium on Cavitation

Devassy, B. Mandumpala^1 ; Edelbauer, W.^1 ; Greif, D.^2

AVL List GmbH, Hans List Platz 1, Graz

8020, Austria^1

AVL-AST D.o.o., Ul. kneza Koclja 22, Maribor

2000, Slovenia^2

关键词: Common rail injector;    Compressibility effects;    Coupled numerical simulation;    Engineering tools;    Multiphase simulations;    Mutual communication;    Spray penetration;    Spray propagation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/656/1/012092/pdf
DOI  :  10.1088/1742-6596/656/1/012092

来源: IOP

【 摘 要 】

Cavitation and its effect on spray formation and its dispersion play a crucial role in proper engine combustion and controlled emission. This study focuses on these effects in a typical common rail 6-hole diesel injector accounting for 3D needle movement and flow compressibility effects. Coupled numerical simulations using 1D and 3D CFD codes are used for this investigation. Previous studies in this direction have already presented a detailed structure of the adopted methodology. Compared to the previous analysis, the present study investigates the effect of 3D needle movement and cavitation on the spray formation for pilot and main injection events for a typical diesel engine operating point. The present setup performs a 3D compressible multiphase simulation coupled with a standalone 1D high pressure flow simulation. The simulation proceeds by the mutual communication between 1D and 3D solvers. In this work a typical common rail injector with a mini-sac nozzle is studied. The lateral and radial movement of the needle and its effect on the cavitation generation and the subsequent spray penetration are analyzed. The result indicates the effect of compressibility of the liquid on damping the needle forces, and also the difference in the spray penetration levels due to the asymmetrical flow field. Therefore, this work intends to provide an efficient and user-friendly engineering tool for simulating a complete fuel injector including spray propagation.