Quantitative analysis of dribble volumes and rates using three-dimensional reconstruction of X-ray and diffused back-illumination images of diesel sprays

[EN] Post-injection fuel dribble is known to lead to incomplete atomisation and combustion due to the release of slow-moving, and often surface-bound, liquid fuel after the end of injection. This can have a negative effect on engine emissions, performance and injector durability. To better quantify this phenomenon, we developed an image-processing approach to measure the volume of ligaments produced during the end of injection. We applied our processing approach to an Engine Combustion Network 'Spray B' 3-hole injector, using datasets from 220 injections generated by different research groups, to decouple the effect of gas temperature and pressure on the fuel dribble process. High-speed X-ray phase-contrast images obtained at room temperature conditions (297 K) at the Advanced Photon Source at Argonne National Laboratory, together with diffused back-illumination images captured at a wide range of temperature conditions (293-900 K) by CMT Motores Termicos were analysed and compared quantitatively. We found a good agreement between image sets obtained by Argonne National Laboratory and CMT Motores Termicos using different imaging techniques. The maximum dribble volume within the field of view of the imaging system and the mean rate of fuel dribble were considered as characteristic parameters of the fuel dribble process. Analysis showed that the absolute mean dribble rate increases with temperature when injection pressure is higher than 1000 bar and slightly decreases at high injection pressures (>500 bar) when temperature is close to 293 K. Larger maximum volumes of the fuel dribble were observed at lower gas temperatures (similar to 473 K) and low gas pressures (<30 bar), with a slight dependence on injection pressure.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The image processing research was supported by the United Kingdom's Engineering and Physical Science Research Council (Grants EP/K020528/1 and EP/M009424/1) and BP Formulated Products Technology. The X-ray measurements were performed at the Advanced Photon Source at Argonne National Laboratory. Use of the Advanced Photon Source (APS) is supported by the U.S. Department of Energy (DOE) under Contract No. DEAC02-06CH11357. The X-ray component of this research was partially funded by DOE's Vehicle Technologies Program, Office of Energy Efficiency and Renewable Energy.Sechenyh, V.; Duke, DJ.; Swantek, AB.; Matusik, KE.; Kastengren, AL.; Powell, CF.; Viera, A.... (2020). Quantitative analysis of dribble volumes and rates using three-dimensional reconstruction of X-ray and diffused back-illumination images of diesel sprays. International Journal of Engine Research. 21(1):43-54. https://doi.org/10.1177/1468087419860955S4354211Örley, F., Hickel, S., Schmidt, S. J., & Adams, N. A. (2016). Large-Eddy Simulation of turbulent, cavitating fuel flow inside a 9-hole Diesel injector including needle movement. International Journal of Engine Research, 18(3), 195-211. doi:10.1177/1468087416643901Benajes, J., Novella, R., De Lima, D., & Tribotté, P. (2014). Analysis of combustion concepts in a newly designed two-stroke high-speed direct injection compression ignition engine. International Journal of Engine Research, 16(1), 52-67. doi:10.1177/1468087414562867Moon, S., Huang, W., Li, Z., & Wang, J. (2016). End-of-injection fuel dribble of multi-hole diesel injector: Comprehensive investigation of phenomenon and discussion on control strategy. Applied Energy, 179, 7-16. doi:10.1016/j.apenergy.2016.06.116Kook, S., Pickett, L. M., & Musculus, M. P. B. (2009). Influence of Diesel Injection Parameters on End-of-Injection Liquid Length Recession. SAE International Journal of Engines, 2(1), 1194-1210. doi:10.4271/2009-01-1356Kastengren, A., Powell, C. F., Tilocco, F. Z., Liu, Z., Moon, S., Zhang, X., & Gao, J. (2012). End-of-Injection Behavior of Diesel Sprays Measured With X-Ray Radiography. Journal of Engineering for Gas Turbines and Power, 134(9). doi:10.1115/1.4006981Manin, J., Bardi, M., Pickett, L. M., & Payri, R. (2016). Boundary condition and fuel composition effects on injection processes of high-pressure sprays at the microscopic level. International Journal of Multiphase Flow, 83, 267-278. doi:10.1016/j.ijmultiphaseflow.2015.12.001Payri, R., Bracho, G., Marti-Aldaravi, P., & Viera, A. (2017). NEAR FIELD VISUALIZATION OF DIESEL SPRAY FOR DIFFERENT NOZZLE INCLINATION ANGLES IN NON-VAPORIZING CONDITIONS. Atomization and Sprays, 27(3), 251-267. doi:10.1615/atomizspr.2017017949Gimeno, J., Martí-Aldaraví, P., Carreres, M., & Peraza, J. E. (2018). Effect of the nozzle holder on injected fuel temperature for experimental test rigs and its influence on diesel sprays. International Journal of Engine Research, 19(3), 374-389. doi:10.1177/1468087417751531Payri, R., Salvador, F. J., Manin, J., & Viera, A. (2016). Diesel ignition delay and lift-off length through different methodologies using a multi-hole injector. Applied Energy, 162, 541-550. doi:10.1016/j.apenergy.2015.10.118Duke, D. J., Matusik, K. E., Kastengren, A. L., Swantek, A. B., Sovis, N., Payri, R., … Powell, C. F. (2017). X-ray radiography of cavitation in a beryllium alloy nozzle. International Journal of Engine Research, 18(1-2), 39-50. doi:10.1177/1468087416685965Duke, D., Swantek, A., Kastengren, A., Fezzaa, K., & Powell, C. (2015). Recent Developments in X-ray Diagnostics for Cavitation. 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X-ray radiography of cavitation in a beryllium alloy nozzle

[EN] Making quantitative measurements of the vapor distribution in a cavitating nozzle is difficult, owing to the strong scattering of visible light at gas-liquid boundaries and wall boundaries, and the small lengths and time scales involved. The transparent models required for optical experiments are also limited in terms of maximum pressure and operating life. Over the past few years, x-ray radiography experiments at Argonne's Advanced Photon Source have demonstrated the ability to perform quantitative measurements of the line of sight projected vapor fraction in submerged, cavitating plastic nozzles. In this paper, we present the results of new radiography experiments performed on a submerged beryllium nozzle which is 520m in diameter, with a length/diameter ratio of 6. Beryllium is a light, hard metal that is very transparent to x-rays due to its low atomic number. We present quantitative measurements of cavitation vapor distribution conducted over a range of non-dimensional cavitation and Reynolds numbers, up to values typical of gasoline and diesel fuel injectors. A novel aspect of this work is the ability to quantitatively measure the area contraction along the nozzle with high spatial resolution. Analysis of the vapor distribution, area contraction and discharge coefficients are made between the beryllium nozzle and plastic nozzles of the same nominal geometry. When gas is dissolved in the fuel, the vapor distribution can be quite different from that found in plastic nozzles of the same dimensions, although the discharge coefficients are unaffected. In the beryllium nozzle, there were substantially fewer machining defects to act as nucleation sites for the precipitation of bubbles from dissolved gases in the fuel, and as such the effect on the vapor distribution was greatly reduced.Raul Payri was funded by a Fulbright visiting scholar grant in collaboration with the Ministry of Education, Culture and Sports of Spain (reference PRX14/00331) while performing this work. Juan P Viera was funded by the Spanish MINECO (grant EEBB-I-15-0976 under project TRA2012-36932).Duke, DJ.; Matusik, KE.; Kastengren, AL.; Swantek, AB.; Sovis, N.; Payri, R.; Viera-Sotillo, JP.... (2017). X-ray radiography of cavitation in a beryllium alloy nozzle. International Journal of Engine Research. 18(1-2):39-50. https://doi.org/10.1177/1468087416685965S3950181-

Athletes Perceive Weighted Baseballs to Carry a Notable Injury Risk, yet Still Use Them Frequently: A Multicenter Survey Study

INTRODUCTION: Weighted baseball use in throwing programs is widespread; however, their use remains controversial. Prior research shows that weighted baseball programs can increase ball velocity but potentially increase throwing arm injuries. This study aims to ascertain perceptions of weighted baseballs among elite baseball players. METHODS: A created online survey questioned common practices, throwing regimens, injury risk factors, and weighted baseball program use. The questions were modeled to ascertain the perceptions of elite baseball players to understand their experience with weighted baseballs. Descriptive statistical analysis was conducted. RESULTS: Three hundred seventy-six baseball players with a mean age of 20 ± 2 years completed the survey; 64% of the players (239/376) were pitchers. 71% (267/376) reported the use of weighted baseballs. Of those, 75% (199/267) thought it made them a better player. Overall, 73% (275/377) thought weighted baseballs are a risk for injury. 17% (46/267) attributed their injury to using weighted baseballs. Overall, participants reported a mean 72% ± 30% likelihood of future weighted baseball use. CONCLUSION: Most of the participating elite adult baseball players reported prior weighted baseball use with a corresponding improvement in pitching performance despite a perceived increased injury risk. Nearly 20% of the players attributed pain or injury to weighted baseball use. Moreover, the players surveyed intend to continue using weighted baseballs because of the perceived performance benefit

Linking instantaneous rate of injection to X-ray needle lift measurements for a direct-acting piezoelectric injector

Internal combustion engines have been and still are key players in today's world. Ever increasing fuel consumption standards and the ongoing concerns about exhaust emissions have pushed the industry to research new concepts and develop new technologies that address these challenges. To this end, the diesel direct injection system has recently seen the introduction of direct-acting piezoelectric injectors, which provide engineers with direct control over the needle lift, and thus instantaneous rate of injection (ROI). Even though this type of injector has been studied previously, no direct link between the instantaneous needle lift and the resulting rate of injection has been quantified. This study presents an experimental analysis of the relationship between instantaneous partial needle lifts and the corresponding ROI. A prototype direct-acting injector was utilized to produce steady injections of different magnitude by partially lifting the needle. The ROI measurements were carried out at CMT-Motores Termicos utilizing a standard injection rate discharge curve indicator based on the Bosch method (anechoic tube). The needle lift measurements were performed at the Advanced Photon Source at Argonne National Laboratory. The analysis seeks both to contribute to the current understanding of the influence that partial needle lifts have over the instantaneous ROI and to provide experimental data with parametric variations useful for numerical model validations. Results show a strong relationship between the steady partial needle lift and the ROI. The effect is non-linear, and also strongly dependent on the injection pressure. The steady lift value at which the needle ceases to influence the ROI increases with the injection pressure. Finally, a transient analysis is presented, showing that the needle velocity may considerably affect the instantaneous ROI, because of the volume displaced inside the nozzle. Results presented in this study show that at constant injection pressure and energizing time, this injector has the potential to control many aspects of the ROI and thus, the heat release rate. Also, data presented are useful for numerical model validations, which would provide detailed insight into the physical processes that drive these observations, and potentially, to the effects of these features on combustion performance.The submitted manuscript has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (Argonne). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. The U.S. Government retains for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government.Viera-Sotillo, JP.; Payri, R.; Swantek, AB.; Duke, DJ.; Sovis, N.; Kastengren, AL.; Powell, CF. (2016). Linking instantaneous rate of injection to X-ray needle lift measurements for a direct-acting piezoelectric injector. Energy Conversion and Management. 112:350-358. https://doi.org/10.1016/j.enconman.2016.01.038S35035811

Internal and near nozzle measurements of Engine Combustion Network "Spray G" gasoline direct injectors

[EN] Gasoline direct injection (GDI) sprays are complex multiphase flows. When compared to multi-hole diesel sprays, the plumes are closely spaced, and the sprays are more likely to interact. The effects of multi-jet interaction on entrainment and spray targeting can be influenced by small variations in the mass fluxes from the holes, which in turn depend on transients in the needle movement and small-scale details of the internal geometry. In this paper, we present a comprehensive overview of a multi-institutional effort to experimentally characterize the internal geometry and near-nozzle flow of the Engine Combustion Network (ECN) Spray G gasoline injector. In order to develop a complete pictitre of the near-nozzle flow, a standardized setup was shared between facilities. A wide range of techniques were employed, including both X-ray and visible-light diagnostics. The novel aspects of this work include both new experimental measurements, and a comparison of the results across different techniques and facilities. The breadth and depth of the data reveal phenomena which were not apparent from analysis of the individual data sets. We show that plume-to-plume variations in the mass fluxes from the holes can cause large-scale asymmetries in the entrainment field and spray structure. Both internal flow transients and small-scale geometric features can have an effect on the external flow. The sharp turning angle of the flow into the holes also causes an inward vectoring of the plumes relative to the hole drill angle, which increases with time due to entrainment of gas into a low-pressure region between the plumes. These factors increase the likelihood of spray collapse with longer injection durations.The X-ray experiments were performed at the 7-BM and 32-ID beam lines of the APS at Argonne National Laboratory. Use of the APS is supported by the U.S. Department of Energy (DOE) under Contract No. DE-AC02-06CH11357. Research was also performed at the Combustion Research Facility, Sandia National Laboratories, Livermore, California. Sandia National Laboratories is managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy National Nuclear Security Administration under contract DE-NA-0003525.Duke, DJ.; Kastengren, AL.; Matusik, KE.; Swantek, AB.; Powell, CF.; Payri, R.; Vaquerizo, D.... (2017). Internal and near nozzle measurements of Engine Combustion Network "Spray G" gasoline direct injectors. Experimental Thermal and Fluid Science. 88:608-621. https://doi.org/10.1016/j.expthermflusci.2017.07.015S6086218