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U. Schmid, G. Krötz, D. Schmitt-Landsiedel:
"A Volumetric Flow Sensor for Automotive Injection Systems";
Journal of Micromechanics and Microengineering, Vol. 18 (2008), 4; 045006.

For further optimization of the automotive power train of diesel engines, advanced combustion
processes require a highly flexible injection system, provided e.g. by the common rail (CR)
injection technique. In the past, the feasibility to implement injection nozzle volumetric flow
sensors based on the thermo-resistive measurement principle has been demonstrated up to
injection pressures of 135 MPa (1350 bar). To evaluate the transient behaviour of the
system-integrated flow sensors as well as an injection amount indicator used as a reference
method, hydraulic simulations on the system level are performed for a CR injection system.
Experimentally determined injection timings were found to be in good agreement with
calculated values, especially for the novel sensing element which is directly implemented into
the hydraulic system. For the first time pressure oscillations occurring after termination of the
injection pulse, predicted theoretically, could be verified directly in the nozzle. In addition, the
injected amount of fuel is monitored with the highest resolution ever reported in the literature.

http://dx.doi.org/10.1088/0960-1317/18/4/045006