Influence of nozzle geometry on spray and combustion characteristics related to large two-stroke engine fuel injection systems
Artikel i vetenskaplig tidskrift, 2021

As emission regulations for large two-stroke marine Diesel engines increase as well, the manufacturers face similar problems as small-sized engine builders. The fuel injection, spray formation and subsequent combustion process remain among the main drivers for emissions of direct-injection, compression-ignition internal combustion engines. Since the fuel injection nozzle design of large two-stroke marine Diesel engines differs significantly, not only in size but especially regarding their non-symmetricity and eccentrical orifice arrangement, compared with four-stroke engines, the bulk of research available related to this topic is very limited. To further deepen the understanding of how in-nozzle cavitation flow during the fuel injection process affects the combustion behaviour in large two-stroke marine Diesel engines, transparent nozzle geometries have been used to link the cavitation phenomena with spray and combustion characteristics. A total of six single-orifice nozzles based on the original five-orifice nozzle design of large two-stroke marine Diesel fuel injectors, with and without hydro-erosive grinding, have been experimentally investigated under realistic engine conditions using highspeed optical measurement techniques and a unique constant-volume spray chamber that geometrically represents a combustion chamber of a large two-stroke marine Diesel engine at top dead centre. The spray morphology and combustion results reveal significant differences between the non- and hydro-erosive ground nozzle geometries. While the standard and angled nozzle versions remain similar, the eccentrical nozzle with its distinctive in-nozzle swirl cavitation pattern behaves differently, leading to a very reliable start of ignition behaviour and extreme wide spray angle.

Spray

Cavitation

Fuel injection

Combustion

Marine diesel engine

Författare

Reto Balz

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

Winterthur Gas and Diesel Ltd.

G. Bernardasci

Winterthur Gas and Diesel Ltd.

Beat von Rotz

Winterthur Gas and Diesel Ltd.

David Sedarsky

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

Fuel

0016-2361 (ISSN)

Vol. 294 120455

Ämneskategorier

Annan maskinteknik

Strömningsmekanik och akustik

DOI

10.1016/j.fuel.2021.120455

Mer information

Senast uppdaterat

2021-03-17