LES of cavitating flow inside a Diesel injector including dynamic needle movement

9th International Symposium on Cavitation

Örley, F.^1 ; Hickel, S.^1,2 ; Schmidt, S.J.^1 ; Adams, N.A.^1

Institute of Aerodynamics and Fluid Mechanics, Department of Mechanical Engineering, Technische Universität München, Germany^1

Department of Computational Aerodynamics, Faculty of Aerospace Engineering, TU Delft, Netherlands^2

关键词: Cavitation characteristics;    Common rail injector;    Diesel injectors;    Homogeneous mixtures;    Immersed boundary methods;    Injection cycles;    Needle movements;    Thermodynamic equilibria;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/656/1/012097/pdf
DOI  :  10.1088/1742-6596/656/1/012097

来源: IOP

【 摘 要 】

We perform large-eddy simulations (LES) of the turbulent, cavitating flow inside a 9-hole solenoid common-rail injector including jet injection into gas during a full injection cycle. The liquid fuel, vapor, and gas phases are modelled by a homogeneous mixture approach. The cavitation model is based on a thermodynamic equilibrium assumption. The geometry of the injector is represented on a Cartesian grid by a conservative cut-element immersed boundary method. The strategy allows for the simulation of complex, moving geometries with sub-cell resolution. We evaluate the effects of needle movement on the cavitation characteristics in the needle seat and tip region during opening and closing of the injector. Moreover, we study the effect of cavitation inside the injector nozzles on primary jet break-up.