Exploration of cavitation-induced erosion metrics in throttle flow simulations

TL;DR

This study uses advanced numerical simulations to evaluate cavitation erosion metrics and mechanisms in throttle flow, identifying cavitation cloud collapse as a key factor in potential material damage.

Contribution

It applies a detailed multiphase flow model with LES and HRM to assess cavitation erosion metrics and visualizes cavitation cloud collapse in throttle geometries.

Findings

Horseshoe cloud implosion predicted at throttle boundary

Model aligns with experimental data on cavitation events

Cavitation cloud collapse linked to erosion risk

Abstract

Although there have been extensive experimental and computational investigations in characterizing cavitation phenomenon in both diesel and gasoline direct injectors, much is still unknown about the mechanisms driving cavitation-induced erosion, and how this complicated fluid-structure interaction should be modeled. To explore current modeling capabilities, a numerical investigation was conducted within the CONVERGE modeling framework to assess proposed cavitation erosion metrics in the literature, and their link to the predicted cavitation cloud collapse mechanism. The multiphase flow within the Winklhofer Throttle U geometry was modeled using a compressible mixture model, where phase change was represented using the Homogeneous Relaxation Model (HRM) and the turbulent flow evolution was modeled using a dynamic structure approach for Large Eddy Simulations (LES). After comparing the model predictions against available experimental data, representative condensation events and potential cavitation erosion sites were identified. The cavitation cloud structures responsible for potential material damage were visualized through the evolution of the vorticity field. For the modeled throttle geometry, it was found that the horseshoe cloud implosion mechanism was predicted to occur and generate excessive impact loads at the throttle boundary.