Method for defined mass flow variations in time and its application to test a mass flow rate meter for pulsating flows

In a previous publication, the authors presented a transient mass flow rate metering technique for pulsating pipe flows and its outstanding performance was demonstrated experimentally for fuel injection nozzles. In the present paper, the application of the mass flow rate metering technique is described for pulsating air flows. The basics of the measuring technique are summarized and the corresponding experimental setup is explained. For verification experiments, a mass flow rate control unit was developed that permits time-varying mass flow rates to be provided proportional to the voltage of an electronic input signal to the unit. The basic ideas of this unit and its performance are summarized. Its application to verify the performance of the developed mass flow rate measuring instrument represents the major part of the paper. Performance tests were carried out for various time variations of mass flow rate pulsations. It is shown that the mass flow rate of the mean flow and that of the pulsating flow can be separated and both can be accurately measured. Comparative measurements show that the mass flow rate measuring technique works very well and reproduces the mass flow rate variations in time imposed by the mass flow rate control unit.