caa a22 4500 606197524 CHVBK 20210128100929.0 cr unu---uuuuu 210128e20150901xx s 000 0 eng 10.1007/s00348-015-2044-1 doi (NATIONALLICENCE)springer-10.1007/s00348-015-2044-1 Planar near-nozzle velocity measurements during a single high-pressure fuel injection [Elektronische Daten] [Raimund Schlüßler, Johannes Gürtler, Jürgen Czarske, Andreas Fischer] In order to reduce the fuel consumption and exhaust emissions of modern Diesel engines, the high-pressure fuel injections have to be optimized. This requires continuous, time-resolved measurements of the fuel velocity distribution during multiple complete injection cycles, which can provide a deeper understanding of the injection process. However, fuel velocity measurements at high-pressure injection nozzles are a challenging task due to the high velocities of up to 300m/s, the short injection durations in the $$\upmu\text{s}$$ μ s range and the high fuel droplet density especially near the nozzle exit. In order to solve these challenges, a fast imaging Doppler global velocimeter with laser frequency modulation (2D-FM-DGV) incorporating a high-speed camera is presented. As a result, continuous planar velocity field measurements are performed with a measurement rate of 200kHz in the near-nozzle region of a high-pressure Diesel injection. The injection system is operated under atmospheric surrounding conditions with injection pressures up to 1400 bar thereby reaching fuel velocities up to 380m/s. The measurements over multiple entire injection cycles resolved the spatio-temporal fluctuations of the fuel velocity, which occur especially for low injection pressures. Furthermore, a sudden setback of the velocity at the beginning of the injection is identified for various injection pressures. In conclusion, the fast measurement system enables the investigation of the complete temporal behavior of single injection cycles or a series of it. Since this eliminates the necessity of phase-locked measurements, the proposed measurement approach provides new insights for the analysis of high-pressure injections regarding unsteady phenomena. Springer-Verlag Berlin Heidelberg, 2015 Schlüßler Raimund Laboratory for Measurement and Sensor System Techniques, Technische Universität Dresden, Helmholtzstr. 18, 01062, Dresden, Germany aut Gürtler Johannes Laboratory for Measurement and Sensor System Techniques, Technische Universität Dresden, Helmholtzstr. 18, 01062, Dresden, Germany aut Czarske Jürgen Laboratory for Measurement and Sensor System Techniques, Technische Universität Dresden, Helmholtzstr. 18, 01062, Dresden, Germany aut Fischer Andreas Laboratory for Measurement and Sensor System Techniques, Technische Universität Dresden, Helmholtzstr. 18, 01062, Dresden, Germany aut Experiments in Fluids Springer Berlin Heidelberg 56/9(2015-09-01), 1-11 0723-4864 56:9<1 2015 56 348 https://doi.org/10.1007/s00348-015-2044-1 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00348-015-2044-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Schlüßler Raimund Laboratory for Measurement and Sensor System Techniques, Technische Universität Dresden, Helmholtzstr. 18, 01062, Dresden, Germany aut NATIONALLICENCE 700 1- Gürtler Johannes Laboratory for Measurement and Sensor System Techniques, Technische Universität Dresden, Helmholtzstr. 18, 01062, Dresden, Germany aut NATIONALLICENCE 700 1- Czarske Jürgen Laboratory for Measurement and Sensor System Techniques, Technische Universität Dresden, Helmholtzstr. 18, 01062, Dresden, Germany aut NATIONALLICENCE 700 1- Fischer Andreas Laboratory for Measurement and Sensor System Techniques, Technische Universität Dresden, Helmholtzstr. 18, 01062, Dresden, Germany aut NATIONALLICENCE 773 0- Experiments in Fluids Springer Berlin Heidelberg 56/9(2015-09-01), 1-11 0723-4864 56:9<1 2015 56 348