Discharge Coefficients under High Pressure Conditions in Small Orifice Diameters
2022-01-0603
03/29/2022
- Event
- Content
- Due to the enhanced requirements for internal combustion engines in terms of emissions and fuel consumption as well as the range of alternative fuels it is necessary to assure detailed understanding of the development of the injection system. Especially the hydraulic behavior is essential to pre-calculate components of the injection system. Remaining questions are related to the fuel behavior under high pressure conditions up to 300 MPa in orifices with small diameter between 200 to 400 microns. The occurring dynamic fluid flow effects like cavitation and temperature rising effects should be investigated under realistic injection system boundary conditions. Therefore, the target of this study is to evaluate the deviations of the flow coefficient from the currently used coefficients in hydraulic 1D-simulations. Up to now the used flow discharge coefficients referring to literature as well as experimental results are only available for a limited range of pressure and temperature conditions. Additional to the variation of inlet pressure the study includes experiments with a variation of the back pressure up to 60 MPa and the influence on the mass flow and the discharge coefficient. To enable a precise validation of the hydraulic 1D-simulation an innovate high pressure hydraulic test bench was developed to carry out the mass flow and pressure measurements at the Institute of Internal Combustion Engines of the Technical University of Munich. This paper should give a brief overview of the test bench setup and development. Afterwards the conclusion from the executed measurements within this study is classified in relation to observed effects from literature.
- Citation
- Stegmann, R., "Discharge Coefficients under High Pressure Conditions in Small Orifice Diameters," SAE Technical Paper 2022-01-0603, 2022, .