Exploring Pilot-Assisted Hydrogen High-Pressure Direct-Injection Engines by Numerical Modeling
conference paper
Hydrogen (H2) High-Pressure Direct-Injection (HPDI) emerges as a promising combustion concept in heavy-duty engines for GHG emissions reduction through the use of a carbonfree main fuel while preserving the high efficiency of a compression ignition engine. A pilot injection of diesel is employed to act as an ignition source for the main fuel, hydrogen, both of which are directly injected into the combustion chamber. H2 HPDI measurements are conducted under various conditions. To gain insights into the details of the fuel injection and combustion processes, an adequate Computational Fluid Dynamics (CFD) simulation is desired. Modeling such a system requires that the injection properties are accurately prescribed. It is found in the literature, that substantial uncertainties exist in these parameters. This research aims to increase the understanding of H2 HPDI combustion through a numerical investigation. Both measurement andCFDsimulation are processed identically, enabling a fair comparison of the apparent rate of heat release (aROHR), which is a key indicator of their combustion phenomena. Reasonable agreement is observed between CFD simulations and measurement data. The uncertainty in the main fuel injection is investigated by varying the inflow boundary conditions. Here it is observed that with the increasing injection pressure and fuel temperature, the jet is ignited earlier and more mixing-controlled combustion is observed. Additionally, a pilot separation sweep is performed, highlighting the importance of the spatial position of the pilot combustion. Retarding the pilot injection significantly suppresses the peak aROHR.
Topics
TNO Identifier
1004064
ISBN
978-0-7918-8852-0
Publisher
ASME
Article nr.
ICEF2024-140005, V001T06A002
Source title
ASME 2024 ICE Forward Conference
Collation
12 p.
Files
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