Fuel nozzle geometry effects on cavitation and spray behavior at diesel engine conditions

Brandon A. Sforzo, Katarzyna E. Matusik, Christopher F. Powell, Alan L. Kastengren, Shane Daly, Scott Skeen, Emre Cenker, Lyle M. Pickett, Cyril Crua, Julien Manin

Research output: Contribution to conferencePaperResearch

Abstract

Cavitation dynamics of diesel and gasoline injection nozzles has been a topic of ongoing research due to the effect of cavitation on the characteristics of the fuel spray, including the discharge coefficient, outlet velocity, spray angle, and atomization process. Additionally, repeated collapse of vapor cavities can damage nozzle surfaces, permanently changing the boundary conditions of the fluid flow field. Understanding the evolution and behavior of cavitation can therefore allow more precise control over its presence, as well as improved predictability of the corresponding fuel spray distribution.

Studies have shown that the inception and persistence of fuel vapor inside the spray hole is sensitive to geometric features of the injection nozzle, such as the degree of taper and inlet corner radius of curvature. For example, a hole with a cylindrical profile and sharp inlet corner more readily supports cavitation formation as compared to a monotonically converging hole with a rounded inlet. To better understand the effect of these geometric features on cavitation formation, and by extension, on the associated fuel spray, we compare the nozzle geometry and spray characteristics of two single-hole diesel injectors procured through collaboration with the Engine Combustion Network (ECN). The Spray C injector, specifically designed by the ECN for the express purpose of studying cavitating flows, features a cylindrical hole with a slight divergence near the outlet and a relatively sharp inlet corner. Its non-cavitating analog, the Spray D injector, contains a rounded inlet corner and a gently converging hole profile.

High-resolution x-ray tomography measurements coupled with optical microscopy images of both injectors provide the nozzle geometry with O(1) µm spatial resolution. Analysis of the measured geometries reveal that the radius of curvature of the hole inlet varies azimuthally for the modestly hydroground Spray C injector. To elucidate the effect that this asymmetric inlet condition has on cavitation formation during operando conditions, the fuel flow inside the nozzle hole was recorded using high-speed x-ray phase contrast imaging. These images reveal the formation of an asymmetric sheath of fuel vapor that persists throughout the injection event. Complementary x-ray and optical diagnostics of the downstream fuel spray further highlight the effect that this cavitation layer has on the spreading angle of the spray in comparison to the non-cavitating Spray D injector.
Original languageEnglish
Number of pages7
Publication statusPublished - 13 May 2018
Event10th International Symposium on Cavitation - Baltimore, United States
Duration: 13 May 201816 May 2018
https://cav2018.jhu.edu

Conference

Conference10th International Symposium on Cavitation
Abbreviated titleCAV2018
CountryUnited States
CityBaltimore
Period13/05/1816/05/18
Internet address

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Cavitation
Diesel engines
Nozzles
Geometry
Vapors
X rays
Engines
Atomization
Optical microscopy
Tomography
Gasoline
Flow of fluids
Flow fields
Boundary conditions
Imaging techniques

Cite this

Sforzo, B. A., Matusik, K. E., Powell, C. F., Kastengren, A. L., Daly, S., Skeen, S., ... Manin, J. (2018). Fuel nozzle geometry effects on cavitation and spray behavior at diesel engine conditions. Paper presented at 10th International Symposium on Cavitation, Baltimore, United States.
Sforzo, Brandon A. ; Matusik, Katarzyna E. ; Powell, Christopher F. ; Kastengren, Alan L. ; Daly, Shane ; Skeen, Scott ; Cenker, Emre ; Pickett, Lyle M. ; Crua, Cyril ; Manin, Julien. / Fuel nozzle geometry effects on cavitation and spray behavior at diesel engine conditions. Paper presented at 10th International Symposium on Cavitation, Baltimore, United States.7 p.
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author = "Sforzo, {Brandon A.} and Matusik, {Katarzyna E.} and Powell, {Christopher F.} and Kastengren, {Alan L.} and Shane Daly and Scott Skeen and Emre Cenker and Pickett, {Lyle M.} and Cyril Crua and Julien Manin",
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Sforzo, BA, Matusik, KE, Powell, CF, Kastengren, AL, Daly, S, Skeen, S, Cenker, E, Pickett, LM, Crua, C & Manin, J 2018, 'Fuel nozzle geometry effects on cavitation and spray behavior at diesel engine conditions' Paper presented at 10th International Symposium on Cavitation, Baltimore, United States, 13/05/18 - 16/05/18, .

Fuel nozzle geometry effects on cavitation and spray behavior at diesel engine conditions. / Sforzo, Brandon A.; Matusik, Katarzyna E.; Powell, Christopher F.; Kastengren, Alan L.; Daly, Shane; Skeen, Scott; Cenker, Emre; Pickett, Lyle M.; Crua, Cyril; Manin, Julien.

2018. Paper presented at 10th International Symposium on Cavitation, Baltimore, United States.

Research output: Contribution to conferencePaperResearch

TY - CONF

T1 - Fuel nozzle geometry effects on cavitation and spray behavior at diesel engine conditions

AU - Sforzo, Brandon A.

AU - Matusik, Katarzyna E.

AU - Powell, Christopher F.

AU - Kastengren, Alan L.

AU - Daly, Shane

AU - Skeen, Scott

AU - Cenker, Emre

AU - Pickett, Lyle M.

AU - Crua, Cyril

AU - Manin, Julien

PY - 2018/5/13

Y1 - 2018/5/13

N2 - Cavitation dynamics of diesel and gasoline injection nozzles has been a topic of ongoing research due to the effect of cavitation on the characteristics of the fuel spray, including the discharge coefficient, outlet velocity, spray angle, and atomization process. Additionally, repeated collapse of vapor cavities can damage nozzle surfaces, permanently changing the boundary conditions of the fluid flow field. Understanding the evolution and behavior of cavitation can therefore allow more precise control over its presence, as well as improved predictability of the corresponding fuel spray distribution. Studies have shown that the inception and persistence of fuel vapor inside the spray hole is sensitive to geometric features of the injection nozzle, such as the degree of taper and inlet corner radius of curvature. For example, a hole with a cylindrical profile and sharp inlet corner more readily supports cavitation formation as compared to a monotonically converging hole with a rounded inlet. To better understand the effect of these geometric features on cavitation formation, and by extension, on the associated fuel spray, we compare the nozzle geometry and spray characteristics of two single-hole diesel injectors procured through collaboration with the Engine Combustion Network (ECN). The Spray C injector, specifically designed by the ECN for the express purpose of studying cavitating flows, features a cylindrical hole with a slight divergence near the outlet and a relatively sharp inlet corner. Its non-cavitating analog, the Spray D injector, contains a rounded inlet corner and a gently converging hole profile.High-resolution x-ray tomography measurements coupled with optical microscopy images of both injectors provide the nozzle geometry with O(1) µm spatial resolution. Analysis of the measured geometries reveal that the radius of curvature of the hole inlet varies azimuthally for the modestly hydroground Spray C injector. To elucidate the effect that this asymmetric inlet condition has on cavitation formation during operando conditions, the fuel flow inside the nozzle hole was recorded using high-speed x-ray phase contrast imaging. These images reveal the formation of an asymmetric sheath of fuel vapor that persists throughout the injection event. Complementary x-ray and optical diagnostics of the downstream fuel spray further highlight the effect that this cavitation layer has on the spreading angle of the spray in comparison to the non-cavitating Spray D injector.

AB - Cavitation dynamics of diesel and gasoline injection nozzles has been a topic of ongoing research due to the effect of cavitation on the characteristics of the fuel spray, including the discharge coefficient, outlet velocity, spray angle, and atomization process. Additionally, repeated collapse of vapor cavities can damage nozzle surfaces, permanently changing the boundary conditions of the fluid flow field. Understanding the evolution and behavior of cavitation can therefore allow more precise control over its presence, as well as improved predictability of the corresponding fuel spray distribution. Studies have shown that the inception and persistence of fuel vapor inside the spray hole is sensitive to geometric features of the injection nozzle, such as the degree of taper and inlet corner radius of curvature. For example, a hole with a cylindrical profile and sharp inlet corner more readily supports cavitation formation as compared to a monotonically converging hole with a rounded inlet. To better understand the effect of these geometric features on cavitation formation, and by extension, on the associated fuel spray, we compare the nozzle geometry and spray characteristics of two single-hole diesel injectors procured through collaboration with the Engine Combustion Network (ECN). The Spray C injector, specifically designed by the ECN for the express purpose of studying cavitating flows, features a cylindrical hole with a slight divergence near the outlet and a relatively sharp inlet corner. Its non-cavitating analog, the Spray D injector, contains a rounded inlet corner and a gently converging hole profile.High-resolution x-ray tomography measurements coupled with optical microscopy images of both injectors provide the nozzle geometry with O(1) µm spatial resolution. Analysis of the measured geometries reveal that the radius of curvature of the hole inlet varies azimuthally for the modestly hydroground Spray C injector. To elucidate the effect that this asymmetric inlet condition has on cavitation formation during operando conditions, the fuel flow inside the nozzle hole was recorded using high-speed x-ray phase contrast imaging. These images reveal the formation of an asymmetric sheath of fuel vapor that persists throughout the injection event. Complementary x-ray and optical diagnostics of the downstream fuel spray further highlight the effect that this cavitation layer has on the spreading angle of the spray in comparison to the non-cavitating Spray D injector.

M3 - Paper

ER -

Sforzo BA, Matusik KE, Powell CF, Kastengren AL, Daly S, Skeen S et al. Fuel nozzle geometry effects on cavitation and spray behavior at diesel engine conditions. 2018. Paper presented at 10th International Symposium on Cavitation, Baltimore, United States.