Session: 06-03: Hydrogen Injection and Mixing

Paper Number: 140005

140005 - Exploring Pilot-Assisted Hydrogen High-Pressure Direct-Injection Engines by Numerical Modeling 

Abstract: 

Hydrogen (H₂) High-Pressure Direct-Injection (HPDI) emerges as a promising combustion concept in heavy-duty engines, for emissions reduction through the use of a carbon-free main fuel while preserving the high efficiency of a compression ignition engine. A pilot fuel injection 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. However, to gain insight 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. To the authors’ knowledge, substantial uncertainties exist in these parameters. This research aims to increase the understanding of H₂ HPDI combustion by numerically investigating the main injection, which contributes to >95% of the total heat released. Therefore, the effect of varying the inflow boundary conditions of the main fuel and their subsequent effect on the combustion process and jet development is investigated. Furthermore, the influence of the ignition source on the combustion behavior of the hydrogen jet is investigated by reducing the separation time between the pilot and the main injection. Both measurement data and CFD simulations are critically and identically processed, enabling a fair comparison of combustion phenomena. Reasonable agreement is observed between CFD simulations and measurement data.

Presenting Author: Nick Diepstraten Eindhoven University of Technology

Presenting Author Biography: Nick received his BSc in Mechanical Engineering from the Eindhoven University of Technology in the Netherlands. He continued his academic career at the same department with a MSc, which he obtained “with great appreciation”. During his studies, he gained experience with both experimental and numerical research. In this master thesis, he numerically analyzed the interaction between a diesel spray and natural gas jet for a dual fuel combustion concept.
Nick is currently a Doctoral Candidate at the Eindhoven University of Technology within the Argon Power Cycle project, which is a hydrogen fueled, emission-free energy conversion system with outstanding thermal efficiency. He researches the Argon Power Cycle using zero to three dimensional numerical models, while specializing in high-pressure hydrogen injections and its subsequent non-premixed combustion process.

Authors:

Tom Leenders Eindhoven University of Technology
Nick Diepstraten Eindhoven University of Technology
Cemil Bekdemir TNO
Jeroen Van Oijen Eindhoven University of Eindhoven