High-Speed Drag Models for Supersonic Spray Combustion Application

2021 ◽  
Author(s):  
HyeJin Oh ◽  
Foluso Ladeinde
Keyword(s):  
High Speed ◽  
Spray Combustion ◽  
Drag Models

Forensic Uncertainty Quantification for Experiments on the Explosively Driven Motion of Particles

2018 ◽  
Vol 3 (4) ◽  
Author(s):  
Kyle Hughes ◽  
S. Balachandar ◽  
Nam H. Kim ◽  
Chanyoung Park ◽  
Raphael Haftka ◽  
...  
Keyword(s):  
Uncertainty Quantification ◽  
High Speed ◽  
Early Time ◽  
Operating Conditions ◽  
Quality Data ◽  
High Speed Photography ◽  
Particle Array ◽  
X Ray Imaging ◽  
Drag Models ◽  
Air Force Research Laboratory

Six explosive experiments were performed in October 2014 and February of 2015 at the Munitions Directorate of the Air Force Research Laboratory with the goal of providing validation-quality data for particle drag models in the extreme regime of detonation. Three repeated single particle experiments and three particle array experiments were conducted. The time-varying position of the particles was captured within the explosive products by X-ray imaging. The contact front and shock locations were captured by high-speed photography to provide information on the early time gas behavior. Since these experiments were performed in the past and could not be repeated, we faced an interesting challenge of quantifying and reducing uncertainty through a detailed investigation of the experimental setup and operating conditions. This paper presents the results from these unique experiments, which can serve as benchmark for future modeling, and also our effort to reduce uncertainty, which we dub forensic uncertainty quantification (FUQ).

Comparison of Flame Dynamics at Stable and Near-LBO Conditions for Swirl-Stabilized Kerosene Spray Combustion

2015 ◽  
Author(s):  
Chi Zhang ◽  
Pengfei Zou ◽  
Bosen Wang ◽  
Xin Xue ◽  
Yuzhen Lin ◽  
...  
Keyword(s):  
Reaction Zone ◽  
High Speed ◽  
Stable Condition ◽  
Axial Direction ◽  
Spray Combustion ◽  
Flame Dynamics ◽  
Major Mode ◽  
The Difference ◽  
Pod Analysis ◽  
Rotation Motion

An experimental investigation was conducted to characterize the flame structures and dynamics at stable and near-lean blowout (LBO) conditions. The current experiments were carried out using a laboratory-scale aero-combustor with an internally-staged dome. The internally-staged injector consisted of pilot and main swirlers, and the pilot swirler was fueled with Chinese kerosene RP-3 while the main injector was chocked. The resulting spray flame was confined within a quartz tube under atmosphere pressure. In the present study, the influence of swirl intensity of the pilot swirler was also investiagted. The OH* chemiluminescence of the flame was recorded by a high-speed camera at a frequency of 2000 Hz. From the high-speed OH* images, the reaction zone was marked and the fluctuation of the reaction zone along axial direction was observed, showing that it became stronger at near-LBO condition than at stable condition. Proper Orthogonal Decomposition (POD) analysis was further used to provide insights into the characteristics of flame dynamics. Based on the POD results, the difference of the flame dynamics between the stable and near-LBO combustion was distinct. While the major Mode l of the flame under stable condition was rotation representing the rotation motion in the swirl flame, at near-LBO condition the flame dynamics included three modes — vibration, rotation, and flame shedding. In addition, for swirl-stabilized kerosene spray combustion investigated herein, the fluctuation of the reaction zone in axial direction became stronger with decreasing equivalence ratio when approaching LBO, and the POD analysis indicated that the Mode l of flame dynamics transitions from the rotation mode to the vibration mode. Although the change of pilot swirl number was found to have little influence on the Mode l of flame dynamics, it was noted to vary the fluctuation energy of the flame.

High speed observation of supercritical DME spray combustion

2017 ◽  
Vol 2017 (0) ◽  
pp. G0700204
Author(s):  
Shinsuke KIKUCHI ◽  
Ryuhei TAKADA ◽  
Yoshihiro OKOSHI ◽  
Yuta MITSUGI ◽  
Kotaro TANAKA ◽  
...  
Keyword(s):  
High Speed ◽  
Spray Combustion

Thrust and Drag Models for Performance Calculations for High-Speed Aircraft

2008 ◽  
Vol 45 (4) ◽  
pp. 1358-1366 ◽  
Author(s):  
David H. Bridges
Keyword(s):  
High Speed ◽  
Drag Models

scholarly journals Spray Combustion Chamber: History and Future of a Unique Test Facility

2017 ◽  
Author(s):  
Andreas Schmid ◽  
Naoki Yamada
Keyword(s):  
Combustion Chamber ◽  
High Speed ◽  
High Energy ◽  
Injection System ◽  
Test Facility ◽  
Spray Combustion ◽  
Future Research ◽  
Nozzle Flow ◽  
Shipping Industry ◽  
Optical Access

Large marine two-stroke diesel engines still represent the major propulsion system for merchant shipping. Withsteadily increasing transport demands, rising operational costs and stricter environmental legislations, the global marine shipping industry finds itself facing the challenge to future-proof its fleet. In order to comply with international maritime organizations emission standards (TIER II and TIER III), highly sophisticated and flexible combustion systems are demanded. With the help of spray and combustion research such systems can be developed and continuously improved. A highly valuable tool to investigate sprays of large marine diesel injectors under engine relevant conditions is the Spray Combustion Chamber (SCC). This paper reviews the history of the SCC, shows todays possibilities and looks into the near future of research involving large marine two-stroke engines. The SCC was built during the first Hercules project (I.P.-HERCULES, WP5, [1]). The initial setup focused on fundamental investigations comprising the application of highly flexible thermodynamic conditions. During follow-up projects (Hercules beta [2] and Hercules C [3]) the SCC was continuously developed, and a variety of influences on spray and combustion were experimentally assessed. The initial SCC design focused on maximum optical access as well as the applicability of a wide span of optical techniques. Single-hole nozzles were utilized to generate reference data to optimize existing spray and combustion simulation models. Different fuel types and fuel qualities were investigated and effects of the in-nozzle flow on spray morphology was identified. A sound set of results was achieved and published in several (internal and public) reports. Over the years, spray research at Winterthur Gas& Diesel has turned its focus from basic spray investigations to more detailed cavitation and in-nozzle flow examinations [4], [5]. Future research on the SCC will focus on investigations of more engine related topics, as, for example, the application of a fuel flexible injection system as is currently developed in the HERCULES-2 project [6]. Significant design modifications of the initial setup were necessary, as the injector positions and therefore exposure of the spray relative to the swirl were not fully congruent with real engine conditions. As a consequence, the new setup includes some minor drawbacks, e.g. the optical access of the nozzle tip is only visible from one side of the chamber. This means that line-of-sight methods are currently only possible at selected positions in the centre of the chamber. Therefore, a new setup was installed to illuminate the spray, consisting of a high speed, high energy laser (100 kHz, 100 W) and special optics. In order to obtain enhanced optical access, tangential windows were re- arranged, now pointing directly at the nozzle. With this setup, a first set of images was realized, showing a realspray as it occurs in large marine two-stroke diesel engines.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4734

High-Speed Observation and Modeling of Dimethyl Ether Spray Combustion at Engine-Like Conditions

2015 ◽  
Vol 9 (1) ◽  
pp. 210-221 ◽  
Author(s):  
Yuta Mitsugi ◽  
Daiki Wakabayashi ◽  
Kotaro Tanaka ◽  
Mitsuru Konno
Keyword(s):  
Dimethyl Ether ◽  
High Speed ◽  
Spray Combustion

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

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