Experimental Measurement Techniques to Optimize Design of Gasoline Injection Valves

In order to reduce the spark-ignition engine exhaust-gas emission and fuel consumption, it is essential that the required air/fuel ratio is maintained under all operating conditions. An important contribution to this claim is delivered by the injection valve by metering the fuel precisely and producing fine atomization. In this report experimental methods to get specific measuring information and methods for optimizing flow in injection valves are described.

Original valves as well as large-scale models were used for the investigations concerning the steady and unsteady-flow characteristics, and were equipped with a number of different sensors.

Holograms of the short-time recording of the spray cone are generated and used for the quantification of the atomization quality when injecting into atmospheric pressure and into vacuum, thus complying with the conditions encountered in the engine intake-manifold. The Phase-Doppler-Anemometer (PDA) serves for rapid on-line measurements with high local resolution.

The results of the experimental investigation methods are also used for the verification of numerical calculations.