Computer Modeling of Steady and Transient Flows Within a Gasoline Fuel Injector

Abstract

Abstract The steady and transient internal flows within an automotive fuel injector are studied by solving ensemble-averaged, three-dimensional mass and momentum conservation equations. In the analysis, the effects of operating pressure, orifice size, and needle lift on the static flow rate, and the effect of opening rate on the dynamic flow rate have been parametricly investigated. Pressure drop was varied from 100 kPa to 500 kPa; the orifice diameter and needle lift ranged between 400 μm to 700 μm and 60 μm to 120 μm, respectively. A multiblock moving mesh method was used to simulate the needle motion. Predicted static flow rates provide good agreements with the experimental measurements. Static flow increases as the orifice diameter increases. For a constant orifice diameter, static flow rate is found sensitive to the changes of the needle lift for a large nozzle while relatively insensitive for the smaller one. Dynamic flows under various needle opening rates are calculated and results are presented.