Computational characterization of hydrogen direct injection and nonpremixed combustion in a compression-ignition engine
Artikel i vetenskaplig tidskrift, 2021

With the revived interest in hydrogen (H ) as a direct combustion fuel for engine applications, a computational study is conducted to assess the characteristics of H direct-injection (DI) compression-ignition (CI) non-premixed combustion concept. Development of a CFD modeling using CONVERGE CFD solver focuses on hydrogen's unique characteristics by utilizing a suitable numerical method to reproduce the direct H injection phenomena. A grid sensitivity study is performed to ensure the fidelity of results with optimal cost, and the models are validated against constant-volume optical chamber and diesel engine experimental data. The present study aims to contribute to the future development of DICI H combustion engines, providing detailed characterization of the combustion cycle, and highlighting several distinct aspects of CI nonpremixed H versus diesel combustion. First, unlike the common description of diesel sprays, hydrogen jets do not exhibit significant flame lift-off and air entrainment near injector nozzle, and the fuel-air interface is drastically more stratified with no sign of premixing. It is also found that the DICI H combustion concept is governed first by a free turbulent jet mixing phase, then by an in-cylinder global mixing phase. The former is drastically more dominant with the DICI H engine compared to conventional diesel engines. The free-jet mixing is also found to be more effective that the global mixing, which indicates the need to completely rethink the optimization strategies for CI engines when using H as fuel. 2 2 2 2 2 2 2 2

Compression ignition

Direct injection

Internal combustion engine

Hydrogen engine

CFD

Hydrogen combustion

Författare

Rafig Babayev

King Abdullah University of Science and Technology (KAUST)

Arne Andersson

Volvo Cars

Albert Serra Dalmau

Volvo Cars

Hong G. Im

King Abdullah University of Science and Technology (KAUST)

Bengt Johansson

Chalmers, Mekanik och maritima vetenskaper, Förbränning och framdrivningssystem, Förbränningsmotorer och framdrivningssystem

International Journal of Hydrogen Energy

0360-3199 (ISSN)

Vol. 46 35 18678-18696

Ämneskategorier

Annan maskinteknik

Rymd- och flygteknik

Strömningsmekanik och akustik

DOI

10.1016/j.ijhydene.2021.02.223

Mer information

Senast uppdaterat

2021-05-12