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Optical Evaluation of Directly Injected Methane Using a Newly Developed Highly Repetitive Laser Diagnostics System

Bayreuth Engine Research Center-Mirko Geiger, Lukas Schroeder, Christian Zoellner, Dieter Brueggemann
Goldlücke GmbH-Juergen Goldluecke lng
Published 2019-09-09 by SAE International in United States
Gaining detailed knowledge about the injection and mixture formation inside engines and combustion chambers during different operation modes is of major importance for improving conventional systems as well as developing new, innovative concepts. To reduce pollutants while maintaining high performance and efficiency an advanced understanding of these mechanisms is necessary. Additional challenges arise when it comes to analyzing transient engine operation and cyclic fluctuations as well as rating their contribution to the formation of emissions. This study contains the evaluations of the injection and mixture formation inside a rapid compression machine (RCM) with directly injected methane. A newly developed highly repetitive optical measurement system based on laser-induced fluorescence (LIF) is used for the quantitative visualizations of the air-fuel equivalence ratio (λ). Various operation conditions, such as different compression ratios, variations of the start of injection, variations of charge pressure as well as different injection pressures allow to evaluate influences on the mixture formation. Interpretations of the recorded images deliver a better understanding of direct injection and mixture processes under engine-like conditions as charge motion and…
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Optical Investigation of Mixture Formation in a Small Bore DISI Engine by Laser Induced Exciplex Fluorescence (LIEF)

Technische Univ. Braunschweig-Alexander Pauls, Peter Eilts
Published 2019-09-09 by SAE International in United States
Legislative and customer demands in terms of fuel consumption and emissions are an enormous challenge for the development of modern combustion engines. Downsizing in combination with turbocharging and direct injection is one way to increase efficiency and therefore meet the requirements. This results in a reduction of the displacement and thus the bore diameter. The emerging trends towards long-stroke engine design and hybridization make the use of small bore diameters in future gasoline engines a realistic scenario. The application of direct injection with small cylinder dimensions increases the probability of the interaction of liquid fuel with the cylinder walls, which may result in disadvantages concerning especially particulate emissions. This leads to the question which bore diameter is feasible without drawbacks concerning emissions as a result of wall wetting. In the previous project “GDI Boundary Bore” the feasibility of an SI engine with direct injection and small bore diameter (60 mm) was shown by the analysis of two different cylinder head concepts (3V and 4V). For the acquirement of deeper understanding of the mixture formation in…
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Optical Distance Measurement at Record-High Speed

  • Magazine Article
  • TBMG-35162
Published 2019-09-01 by Tech Briefs Media Group in United States

Scientists of Karlsruhe Institute of Technology (KIT) and École Poly-technique Fédérale de Lausanne (EPFL) have reported that they achieved the fastest distance measurement attained so far. The researchers demonstrated on-the-fly sampling of a gun bullet profile with micrometer accuracy. The experiment relied on a soliton frequency comb generated in a chip-based optical microresonator made from silicon nitride. Potential applications include real-time 3D cameras based on highly precise and compact LIDAR systems.

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Machine Vision Applications in Laser Measurement Systems

  • Magazine Article
  • TBMG-35167
Published 2019-09-01 by Tech Briefs Media Group in United States

Machine vision is a broad term with many applications and definitions, but at its most basic definition it is using an imager or camera along with software to inspect and analyze a real world object. In addition to the camera and software, machine vision systems usually include lighting, optics, and pass/fail mechanisms.

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New Sensor Could Shake Up Earthquake Response Efforts

  • Magazine Article
  • TBMG-35192
Published 2019-09-01 by Tech Briefs Media Group in United States

A new optical sensor developed at Lawrence Berkeley National Laboratory (Berkeley Lab) could speed up the time it takes to evaluate whether critical buildings are safe to occupy shortly after a major earthquake.

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3D Meta-Optics for High-Energy Lasers

Aerospace & Defense Technology: September 2019

  • Magazine Article
  • 19AERP09_09
Published 2019-09-01 by SAE International in United States

Engineering electromagnetic fields in 3D dielectric structures to change the way components are designed and fabricated for high-energy laser (HEL) applications.

The scope of this research radically changed the way novel components are designed and fabricated for high-energy applications. This 3D Meta-Optics platform was, and is, essentially engineering the electromagnetic fields in 3D dielectric structures. The results have provided a class of transformational optical components that can be integrated at all levels throughout a high-energy laser system.

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Precise Temperature Measurements with Invisible Light

  • Magazine Article
  • TBMG-35139
Published 2019-09-01 by Tech Briefs Media Group in United States

A portable, stable, standards-quality radiation thermometer was invented that can measure temperatures between -50 °C (-58 °F) to 150 °C (302 °F). The corresponding infrared wavelengths are from 8 to 14 micrometers.

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New Optical Endoscopy Using Ultrasound Could Replace Scopes

  • Magazine Article
  • TBMG-35101
Published 2019-09-01 by Tech Briefs Media Group in United States

One day, scopes may no longer need to be inserted into the body — such as down the throat or under the skin — to reach the stomach, brain, or any other organs for examination.

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Ultrafast Optics: Vector Cavity Lasers — Physics and Technology

  • Magazine Article
  • TBMG-35105
Published 2019-09-01 by Tech Briefs Media Group in United States

Fiber lasers have found widespread applications in industrial material processing, scientific research and military systems due to their advantages of easy maintenance, excellent stability, compact size and low cost. One characteristic of fiber lasers, compared to other types of lasers, is that strong light is confined to propagating a long distance in a fiber core that has a very small cross-sectional area. This has the consequence that the nonlinear light interaction with the matter has a very long length. This results in the strength of all nonlinear optical processes being strongly amplified. This means that a conventionally weak, nonlinear optical effect can become significant. Therefore, apart from the practical applications, fiber lasers also constitute an ideal platform for the exploration of various complex nonlinear dynamics.

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3D Optical Scanner

  • Magazine Article
  • TBMG-35116
Published 2019-09-01 by Tech Briefs Media Group in United States

NVision, Inc. Southlake, TX 817-416-8006