Title: Numerical study on spray collapse process of ECN spray G injector under flash boiling conditions

Abstract

This work features a numerical study of the spray collapse process that occurs under flash-boiling, gasoline-direct-injection conditions. The Engine Combustion Network's Spray G injector was modeled, and iso-octane, n-hexane, and propane were used as fuels with the goal to investigate fuel property effects. The development of individual jets and jet-to-jet interaction were analyzed to reveal the physical mechanisms of spray collapse. The results agreed qualitatively well with the experimental data of propane available from the literature and the predictions revealed the model's ability to capture the near-nozzle shock structures witnessed in the experiments. Simulations showed that the flow development of flashing sprays was strongly tied with the fuel properties. Specifically, under-expanded jets were not observed with iso-octane due to the fuel's low vapor pressure. In the case of n-hexane, the jets were under-expanded, and a low-pressure core was observed inside the jets due to the flow expansion. With propane, the very strong expansion caused the flow to become transonic and generate a unique shock structure near the nozzle exit. The shock structure revealed the formation of primary shock cells within the jets and secondary shock cells induced by jet-to-jet interaction. Based on the results, the spray collapse under flash boilingmore » conditions was mainly attributed to two effects, i.e., the decrease in pressure at the spray center induced by the low-pressure cores inside and between the jets, and the isolation effect due to the jet-to-jet interaction which contributed to maintain the pressure differential between the spray center and the ambient.« less

Authors:

Guo, Hengjie ^[1]; Nocivelli, Lorenzo ^[1]; Torelli, Roberto ^[1]

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+ Show Author Affiliations

1. Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Div.

Publication Date:

Fri Dec 25 00:00:00 EST 2020

Research Org.:

Argonne National Lab. (ANL), Argonne, IL (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE), Transportation Office. Vehicle Technologies Office; USDOE Office of Energy Efficiency and Renewable Energy (EERE)

OSTI Identifier:

1777221

Alternate Identifier(s):

OSTI ID: 1810933

Grant/Contract Number:  

AC02-06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

Fuel

Additional Journal Information:

Journal Volume: 290; Journal ID: ISSN 0016-2361

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

42 ENGINEERING; flash boiling; jet-to-jet interaction; shock wave; spray collapse; under-expanded jet