A parametric study of a fuel injector timing check valve using computational fluid dynamics.

摘要

This project stems from the flow variation of a check valve design used by Cummins Engine Company to prevent the backflow of fuel out of the fuel injector during the injection process. The check valve assembly is calibrated using a steady state flow method to a specification of 915 ± 20 Ibs per hour (pph) at 150 psi. In production, the check valve historically caused approximately 40 percent of the assemblies to fail inspection and required them to be refitted with an once rated for greater or lesser flow before final assembly of the injector. The refitting process can be very time consuming due to the inconsistent and unpredictable flows achieved by fitting the assembly in an intuitive fashion, i.e. replacing the low flow orifice plate with one of greater flow may result in a lower flow for the complete assembly. It was also found that the stroke of the timing disk also affects flow in a counter-intuitive fashion.; The scope of this project consists of performing a computational study analyzing mass flow through the check valve and comparison to experimental data with the purpose of explaining the phenomena responsible for the mass flow variation. (Abstract shortened by UMI.)