Quantitative X-ray measurements of high-pressure fuel sprays from a production heavy duty diesel injector

Turbochargers are a key technology for reducing the fuel consumption and CO2 emissions of heavy-duty internal combustion engines by enabling greater power density, which is essential for engine downsizing and downspeeding. This in turn raises turbine expansion ratio levels and drives the shift to air systems with multiple stages, which also implies the need for interconnecting ducting, all of which is subject to tight packaging constraints. This paper considers the challenges in the aerodynamic optimization of the exhaust side of a two-stage air system for a Caterpillar 4.4-litre heavy-duty diesel engine, focusing on the high pressure turbine wheel and interstage duct. Using the current production designs as a baseline, a genetic algorithm-based aerodynamic optimization process was carried out separately for the wheel and duct components in order to minimize the computational effort required to evaluate seven key operating points. While efficiency was a clear choice for the cost function for turbine wheel optimization, the most appropriate objective for interstage duct optimization was less certain, and so this paper also explores the resulting effect of optimizing the duct design for different objectives. Results of the optimization generated differing turbine wheel and interstage duct designs depending on the corresponding operating point, thus it was important to check the performance of these components at every other operating point, in order to determine the most appropriate designs to carry forward. Once the best compromise high pressure turbine wheel and interstage duct designs were chosen, prototypes of both were manufactured and then tested together against the baseline designs to validate the CFD predictions. The best performing high pressure turbine design, wheel A, was predicted to show an efficiency improvement of 2.15 percentage points, for on-design operation. Meanwhile, the optimized interstage duct contributed a 0.2 and 0.5 percentage-point efficiency increase for the high and low pressure turbines, respectively.

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A supercharged heavy-duty diesel single-cylinder research engine for high-pressure direct injection of natural gas

International Journal of Engine Research ◽

10.1243/146808703322743912 ◽

2003 ◽

Vol 4 (4) ◽

pp. 315-330 ◽

Cited By ~ 31

Author(s):

G. P. McTaggart-Cowan ◽

W. K. Bushe ◽

P. G. Hill ◽

S. R. Munshi

Keyword(s):

High Pressure ◽

Natural Gas ◽

Direct Injection ◽

Heavy Duty ◽

Single Cylinder ◽

Heavy Duty Diesel

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X-ray Imaging of Shock Waves Generated by High-Pressure Fuel Sprays

Science ◽

10.1126/science.1068149 ◽

2002 ◽

Vol 295 (5558) ◽

pp. 1261-1263 ◽

Cited By ~ 90

Author(s):

A. G. MacPhee

Keyword(s):

High Pressure ◽

Shock Waves ◽

X Ray ◽

Fuel Sprays ◽

X Ray Imaging

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Electronically Controlled High Pressure Injection System for Heavy Duty Diesel Engine - KOMPICS

10.4271/810997 ◽

1981 ◽

Cited By ~ 2

Author(s):

K. Komiyama ◽

T. Okazaki ◽

K. Togashi ◽

H. Hashimoto ◽

K. Takase

Keyword(s):

High Pressure ◽

Diesel Engine ◽

Injection System ◽

Heavy Duty ◽

Pressure Injection ◽

Heavy Duty Diesel Engine ◽

Heavy Duty Diesel ◽

High Pressure Injection

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Cavitation-Suppressing Orifice Design Applied to a Heavy-Duty Diesel Engine Injector Operating With Gasoline

ASME 2020 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2020-2994 ◽

2020 ◽

Author(s):

Roberto Torelli ◽

Yuanjiang Pei ◽

Yu Zhang ◽

Michael Traver ◽

Sibendu Som

Keyword(s):

Volume Fraction ◽

Numerical Models ◽

Injection Pressure ◽

Design Parameters ◽

Fuel Vapor ◽

Radius Of Curvature ◽

Heavy Duty ◽

X Ray ◽

Heavy Duty Diesel ◽

Injector Design

Abstract Measurements of fuel injectors via non-destructive X-ray techniques can provide unique insights about an injector’s internal surface. Using real measured geometry rather than nominal design geometry in computational fluid dynamics simulations can improve the accuracy of the numerical models dramatically. Recent work from the authors investigated the influence of the injector design on the internal flow development and occurrence of cavitation in a production multi-hole heavy-duty diesel injector operating with a straight-run gasoline for gasoline compression ignition (GCI) applications. This was achieved by evaluating a series of design parameters which showed that the intensity and duration of cavitation structures could be mitigated by acting on certain injector parameters such as K-factor, orifice inlet ellipticity, and sac-to-orifice radius of curvature. In the present work, the findings from the previous parametric study were combined to generate two attempts at improving the injector design and numerically evaluate their ability to suppress cavitation inside the orifices at three levels of injection pressure (1000, 1500, and 2500 bar), while operating with the same high-volatility gasoline fuel. Qualitative and quantitative analyses showed that, compared to the results obtained with the original X-ray scanned geometry, the improved designs were able to prevent fuel vapor formation at the two lowest injection pressures and avoid super-cavitation at the higher pressure. It was shown that these results were due to the strong influence that the orifice shape can have on the pressure and fuel vapor volume fraction distributions within the orifices. The informed design choices proposed in this study can therefore be vital for extending the durability and reliability of heavy-duty injectors for GCI applications.

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Aerodynamic Optimization of the High Pressure Turbine and Interstage Duct in a Two-Stage Air System for a Heavy-Duty Diesel Engine

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4038024 ◽

2017 ◽

Vol 140 (5) ◽

Cited By ~ 5

Author(s):

Uswah B. Khairuddin ◽

Aaron W. Costall

Keyword(s):

High Pressure ◽

Diesel Engine ◽

Heavy Duty ◽

Aerodynamic Optimization ◽

High Pressure Turbine ◽

Two Stage ◽

Turbine Wheel ◽

Heavy Duty Diesel Engine ◽

Heavy Duty Diesel ◽

Engine Operating Point

Turbochargers reduce fuel consumption and CO2 emissions from heavy-duty internal combustion engines by enabling downsizing and downspeeding through greater power density. This requires greater pressure ratios and thus air systems with multiple stages and interconnecting ducting, all subject to tight packaging constraints. This paper considers the aerodynamic optimization of the exhaust side of a two-stage air system for a Caterpillar 4.4 l heavy-duty diesel engine, focusing on the high pressure turbine (HPT) wheel and interstage duct (ISD). Using current production designs as a baseline, a genetic algorithm (GA)-based aerodynamic optimization process was carried out separately for the wheel and duct components to evaluate seven key operating points. While efficiency was a clear choice of cost function for turbine wheel optimization, different objectives were explored for ISD optimization to assess their impact. Optimized designs are influenced by the engine operating point, so each design was evaluated at every other engine operating point, to determine which should be carried forward. Prototypes of the best compromise high pressure turbine wheel and ISD designs were manufactured and tested against the baseline to validate computational fluid dynamics (CFD) predictions. The best performing high pressure turbine design was predicted to show an efficiency improvement of 2.15% points, for on-design operation. Meanwhile, the optimized ISD contributed a 0.2% and 0.5% point efficiency increase for the HPT and low pressure turbine (LPT), respectively.

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High-Pressure Injection Pumps with Electronic Control for Heavy-Duty Diesel Engines

10.4271/850170 ◽

1985 ◽

Cited By ~ 5

Author(s):

R. Schwartz

Keyword(s):

High Pressure ◽

Diesel Engines ◽

Electronic Control ◽

Heavy Duty ◽

Pressure Injection ◽

Heavy Duty Diesel ◽

High Pressure Injection

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Nano-probe x-ray analysis and high-resolution imaging on planar defects in high-pressure synthesized infinite-layer superconductor

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171377 ◽

1994 ◽

Vol 52 ◽

pp. 728-729

Author(s):

Y. Y. Wang ◽

H. Zhang ◽

V. P. Dravid ◽

H. Zhang ◽

L. D. Marks ◽

...

Keyword(s):

High Pressure ◽

High Resolution ◽

Atomic Structure ◽

Emission Spectra ◽

High Resolution Electron Microscopy ◽

Planar Defects ◽

X Ray ◽

Infinite Layer ◽

Resolution Electron ◽

Resolution Imaging

Azuma et al. observed planar defects in a high pressure synthesized infinitelayer compound (i.e. ACuO2 (A=cation)), which exhibits superconductivity at ~110 K. It was proposed that the defects are cation deficient and that the superconductivity in this material is related to the planar defects. In this report, we present quantitative analysis of the planar defects utilizing nanometer probe xray microanalysis, high resolution electron microscopy, and image simulation to determine the chemical composition and atomic structure of the planar defects. We propose an atomic structure model for the planar defects.Infinite-layer samples with the nominal chemical formula, (Sr1-xCax)yCuO2 (x=0.3; y=0.9,1.0,1.1), were prepared using solid state synthesized low pressure forms of (Sr1-xCax)CuO2 with additions of CuO or (Sr1-xCax)2CuO3, followed by a high pressure treatment.Quantitative x-ray microanalysis, with a 1 nm probe, was performed using a cold field emission gun TEM (Hitachi HF-2000) equipped with an Oxford Pentafet thin-window x-ray detector. The probe was positioned on the planar defects, which has a 0.74 nm width, and x-ray emission spectra from the defects were compared with those obtained from vicinity regions.

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