Page 33

Solutionskatalog_2017_E

Injection Nozzle Flow, Cavitation and Erosion / 34 SIMULATION SOLUTIONS Vehicle System Injection Nozzle Flow, Cavitation and Erosion Combustion and Emissions Turbocharging Exhaust Gas Aftertreatment Transmission and Driveline Durability and NVH Electrification Thermal Management and Aerodynamics Calibration and Testing Quenching TEST SYSTEM SOLUTIONS TESTING EQUIPMENT SIMULATION TOOLS TESTING TOOLS CUSTOMER SERVICES AVL BOOST™ HYDSIM and AVL FIRE™ offer indispensable capabilities when it comes to the development and optimization of injection nozzles. While one-dimensional AVL BOOST™ HYDSIM models typically re��ect the complete injection system from fuel tank to the injector, AVL FIRE™ focuses on the three-dimensional calculation of ��uid ��ow in the injection nozzle. In an early engine design stage, fuel injection details, such as needle lift and inlet pressure level are not known. In a virtual prototyping environment, coupled 1D/3D fuel injection simulations are extremely valuable. While AVL BOOST™ HYDSIM provides the information about longitudinal and radial needle displacements as well as pressure levels, AVL FIRE™ improves the accuracy of the 1D solution by providing pressure forces acting on the needle and local ��ow rates. THE TRUTH IS MULTI-PHASE Modern injection systems make use of high pump pressures to enhance droplet break-up and mixture formation in the combustion cham��er, targeting high performance, high efficiency and low engine-out emissions. The resulting huge pressure differences between the fuel supply line and the combustion chamber lead to a phase change from liquid fuel to fuel vapor. While the vapor reduces the effective orifice outlet area and, therefore, the amount of liquid fuel transported into the combustion chamber during a single injection event, it also affects the conditions that determine the release of the fuel droplets furtherdown the nozzle orifices. To accurately account for the effect of cavitation on fuel penetration and propagation in the combustion chamber, AVL FIRE™ offers advanced cavitation modeling. This capability enables accurate prediction of transient discharge rates and detailed insight into the instationary ��ow conditions in the nozzle orifice e��it areas. LES applied on a realistic diesel injector featuring three-phase flow and needle movement Cavitating internal nozzle flow applied as input for combusting in-cylinder flow


Solutionskatalog_2017_E
To see the actual publication please follow the link above