1. Transient cavitation and friction-induced heating effects of diesel fuel during the needle valve early opening stages for discharge pressures up to 450 mpa
- Author
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Robert M. McDavid, Konstantinos Kolovos, Manolis Gavaises, and Phoevos Koukouvinis
- Subjects
Technology ,Control and Optimization ,Materials science ,Common rail ,Needle valve ,020209 energy ,Nozzle ,Energy Engineering and Power Technology ,02 engineering and technology ,law.invention ,Physics::Fluid Dynamics ,Diesel fuel ,020401 chemical engineering ,cavitation ,law ,0202 electrical engineering, electronic engineering, information engineering ,real-fluid ,0204 chemical engineering ,Electrical and Electronic Engineering ,Engineering (miscellaneous) ,QC ,450 MPa injection pressure ,Renewable Energy, Sustainability and the Environment ,erosion ,LES ,ALE ,Turbulence modeling ,Injector ,Mechanics ,TA ,Cavitation ,Energy (miscellaneous) ,Large eddy simulation - Abstract
An investigation of the fuel heating, vapor formation, and cavitation erosion location patterns inside a five-hole common rail diesel fuel injector, occurring during the early opening period of the needle valve (from 2 μm to 80 μm), discharging at pressures of up to 450 MPa, is presented. Numerical simulations were performed using the explicit density-based solver of the compressible Navier–Stokes (NS) and energy conservation equations. The flow solver was combined with tabulated property data for a four-component diesel fuel surrogate, derived from the perturbed chain statistical associating fluid theory (PC-SAFT) equation of state (EoS), which allowed for a significant amount of the fuel’s physical and transport properties to be quantified. The Wall Adapting Local Eddy viscosity (WALE) Large Eddy Simulation (LES) model was used to resolve sub-grid scale turbulence, while a cell-based mesh deformation arbitrary Lagrangian–Eulerian (ALE) formulation was used for modelling the injector’s needle valve movement. Friction-induced heating was found to increase significantly when decreasing the pressure. At the same time, the Joule–Thomson cooling effect was calculated for up to 25 degrees K for the local fuel temperature drop relative to the fuel’s feed temperature. The extreme injection pressures induced fuel jet velocities in the order of 1100 m/s, affecting the formation of coherent vortical flow structures into the nozzle’s sac volume.
- Published
- 2021