The numerical calculation of the flow in a diesel fuel injector
The efficiency of operation of modern diesel engines largely depends on the parameters of the fuel supply system and, in particular, on the geometry of flow channels of injectors. The unreasonable labor consumption and excessive complexity of field experiments do not enable us to obtain the most reliable parameters of the flow inside the injector. For this reason, a numerical simulation of the flow in a diesel engine fuel injector was conducted on the basis of the ANSYS-CFX computational fluid dynamics software package. The velocity field and the total and static pressure were computed in the case of unsteady flow. The integral values of the velocity and pressure were calculated at all points of the injector channel in order to determine the injection nozzle flow rate and to find the area of flow separation from the channel walls. The results of numerical and full-scale experiments agree within the error of less than 1%. The further processing of the numerical results and the optimization of the flow channel geometry can do much towards improving the fuel flow parameters, which, in turn, will enhance the technical, economic and environmental characteristics of the engine.