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Technical Paper

Laser surface treatment machine for Ariane 6 Cryogenic Tanks

2019-09-16
2019-01-1897
Surface treatment of cryogenic tanks (liquid oxygen and liquid hydrogen) for the Ariane 6 Space Launcher is a critical step for the adhesion of insulation materials. This operation is currently performed by the help of chemical products which are for some of them carcinogenic, mutagenic and repro-toxic. The large tank dimensions require using an important quantity of those products which generate massive recurring costs and health and environment problems. ArianeGroup has previously qualified and patented the Laser Surface Treatment as a replacement solution to chemical process. The aim is to use energy provided by infrared laser beam to modify the top layer of the tank surface. The chosen technology is Nd-YAG pulsed laser. Electroimpact has been chosen to carry out the industrial application.
Technical Paper

NDT Application from Conventional to Digital Radiography for the Aircraft Maintenance Industry

2019-09-16
2019-01-1907
Technological innovation can provide improved productivity, increased cost savings, and it can keep or make an organisation competitive. Digital radiography for non-destructive testing (NDT) is such a promising innovation. In organisations with large scale utilisation of non-destructive testing, a transition from film to digital radiography is easily justified. Nevertheless, this is not the case for every organisation. Next to the operational workflow, system flexibility, quality, and regulatory issues also play a role in the trade-off. Especially in the aircraft maintenance industry, where the non-destructive operation is related to a lot of different factors. Motivated by the developments of digital radiography, the NDT department of KLM Engineering & Maintenance (E&M) requested advice in reconsidering their conventional film radiography capabilities. The objective of this research was to assess the feasibility of digital radiography at KLM E&M.
Technical Paper

Improving competitiveness of Additive Manufacturing Aerospace serial parts

2019-09-16
2019-01-1900
The interest of selective laser melting technology for aerospace parts is very high due to their high complexity and their freedom of design which allow functions integration. However, the competitiveness of Laser Beam Melting (LBM) machines for aerospace industry is limited by two major road blocks. On the one hand, basic parametric set sold with LBM machines are more oriented to historical qualification than productivity rates. For instance, the ongoing qualification on EOS M290 by AIRBUS COMMERCIAL AIRCRAFT only enables us to produce a hundred pieces per machine per year. On the other hand, wasted times between two consecutive manufacturing batches are significant and are impacting the yearly output of the machines. The present project focuses on two activities, focusing on the largest available machines, XLINE2000R and M400, in order to maximize the amount of pieces per build.
Technical Paper

High-speed imaging of a vaporizing GDI spray: a comparison between Schlieren, Shadowgraph, DBI and Scattering

2019-08-15
2019-24-0037
The evolution of the liquid and vapor phases of an iso-octane GDI spray was investigated in a constant volume vessel, under inert environment, using high-speed imaging techniques. The tests were performed in nitrogen, at temperatures and density varying between the operating conditions representative of late injection, flash boiling conditions and early injection in a GDI engine. Large scale parameters of the spray (penetration length, spray angle, projected area) were obtained by processing schlieren, shadowgraph, DBI and scattering images. The segmentation of spray images, for both the liquid and vapor phase, was carried out through a novel image processing method. The method bases upon an "optimal" filtering of spray images by means of variational methods, an original thresholding procedure based on the iterative application of the Otsu's method, and the highlighting of the schlieren/shadowgraph textures of the vapor phase through the main curvatures of the image surface.
Technical Paper

Morphological characterisation of gasoline soot-in-oil: development of semi-automated 2D-TEM and comparison with novel high-throughput 3D-TEM

2019-08-15
2019-24-0042
Morphology of soot nanoparticles is characteristically complex and 3-dimensional, and plays a defining role in soot-related phenomena. Morphological characterisation of soot is essential to understand the extent of such effects, including harm to human health, and develop strategies to mitigate them. Use of 2D-TEM for characterisation is associated with numerous and significant sources of error and uncertainty related to a 2D-3D information gap. Volume reconstruction by 3D-TEM avoids many of these sources of error, and has been shown in simulation studies to be highly accurate. However, the technique has traditionally been too slow to permit study of enough individual structures to satisfactorily characterise a bulk soot-sample. Similarly, the prevalence of manual image processing in 2D-TEM studies of soot can limit characterisations to as few as 50 individual particles per sample.
Technical Paper

Imaging and vibro-acoustic diagnostic techniques comparison for a GDI fuel injector

2019-08-15
2019-24-0058
This work presents the results of an experimental investigation on a GDI injector, in order to analyze fuel injection process and atomization phenomenon, correlating imaging and vibro-acoustic diagnostic techniques. A single-hole, axially-disposed, 0.200 mm diameter GDI injector was used to spray commercial gasoline in a test chamber at room temperature and atmospheric backpressure. The explored injection pressures were ranged from 5.0 to 20.0 MPa. Cycle-resolved acquisitions of the spray evolution were acquired by a high-speed camera. Contemporarily, the vibro-acoustic response of the injector was evaluated. More in detail, noise data acquired by a microphone sensor were analyzed for characterizing the acoustic emission of the injection, while a spherical loudspeaker was used to excite the spray injection at a proper distance detecting possible fuel spray resonance phenomena.
Technical Paper

Large Eddy Simulations and Tracer-LIF Diagnostics of wall film dynamics in an optically accessible GDI research engine

2019-08-15
2019-24-0131
Large Eddy Simulations (LES) and tracer-based Laser Induced Fluorescence (LIF) measurements have been performed to study the dynamics of fuel wall-films on the piston top of an optically accessible, four-valve pent-roof GDI research engine for a total of eight operating conditions. Starting from a reference point, the systematic variations include changes in engine speed (600; 1,200 and 2,000 RPM) and load (WOT and 500 mbar intake pressure); concerning the fuel path the Start Of Injection (SOI=360°, 390° and 420° CA after gas exchange TDC) as well as the injection pressure (10, 20 and 35 MPa) have been varied. For each condition, 40 experimental images were acquired phase-locked at 10° CA intervals after SOI, providing valuable insights with respect to the wall film dynamics in terms of spatial extent, thickness and temperature.
Technical Paper

Experimental characterization of methane direct injection from an outward-opening poppet-valve injector

2019-08-15
2019-24-0135
The in-cylinder direct injection of natural gas represents a further step towards cleaner and more efficient internal combustion engines (ICE). However, the injector design and its characterization, either experimentally or from numerical simulation, is challenging because of the complex fluid dynamics related to gas compressibility. In this work, the underexpanded flow of methane from an outward-opening poppet-valve injector has been experimentally characterized by Schlieren and Shadowgraph high-speed imaging. The jet evolution was also followed through Mie-scattering imaging using n-heptane droplets as a tracer. The investigation has been performed at ambient temperature and pressure and different nozzle pressure ratios (NPR) ranging from 10 to 17. The gaseous jet has been characterized in terms of its macroscale parameters.
Technical Paper

Optical investigation of mixture formation in a small bore DISI engine by laser induced exciplex fluorescence (LIEF)

2019-08-15
2019-24-0133
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 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. The emerging trends towards long-stroke engine design and hybridization make the use of small bore diameters in future gasoline engines a realistic scenario.
Technical Paper

Optical evaluation of directly injected methane using a newly developed highly repetitive laser diagnostics system

2019-08-15
2019-24-0134
New certification procedures like WLTP and RDE, as well as more stringent emission regulations in general, demand for further improvements in engine research and development. In order to meet the challenges of reducing pollutants while maintaining high performance and high efficiency many different approaches are discussed. Beside various concepts for new combustion strategies and alternative fuels, gaining detailed knowledge about the ongoing processes inside engines and combustion chambers during the different operation modes is of major importance. With their influence on combustion and emission formation, fuel injection and mixture formation are playing an important role for further improvements in modern propulsion systems. With the help of optical measurement systems based on laser induced (exciplex) fluorescence (LIF/ LIEF), an advanced understanding of these mechanisms can be obtained.
Training / Education

Photography for Accident Reconstruction, Product Liability, and Testing

2019-08-12
Many technical projects, most vehicle and component testing, and all accident reconstructions, product failure analyses, and other forensic investigations, require photographic documentation. Roadway evidence disappears, tested or wrecked vehicles are repaired, disassembled, or scrapped, and components can be tested to failure. Photographs are frequently the only evidence that remains of a wreck, or the only records of subjects before or during tests. Making consistently good images during any inspection is a critical part of the evaluation process.
Training / Education

LIDAR and Infrared Cameras for ADAS and Autonomous Sensing

2019-08-06
This two-day seminar examines ADAS and autonomous vehicle technologies that have disrupted the traditional automotive industry with their challenges and potential to increase safety while attempting to optimize the cost of car ownership. LIDAR and Infrared camera sensing are seeing a rapid growth and adoption in the industry. However, the sensor requirements and system architecture options continue to evolve almost every six months. This course will provide the foundation to build on for these two technologies in automotive applications. It will include a demonstration model for LIDAR and Infrared camera.
Training / Education

Photogrammetry and Analysis of Digital Media

2019-06-26
Photographs and video recordings of vehicle crashes and accident sites are more prevalent than ever, with dash mounted cameras, surveillance footage, and personal cell phones now ubiquitous. The information contained in these pictures and video provide critical information to understanding how crashes occurred, and in analyzing physical evidence. This course teaches the theory and techniques for getting the most out of digital media, including correctly processing raw video and photographs, correcting for lens distortion, and using photogrammetric techniques to convert the information in digital media to usable scaled three-dimensional data.
Technical Paper

An Experimental Study on a Hot-Air-Based Anti-/De-Icing System for the Icing Protection of Aero-Engine Inlet Guide Vanes

2019-06-10
2019-01-2039
In the present study, an experimental investigation was conducted to characterize a hot-air-based anti-/de-icing system for the icing protection of aero-engine inlet guide vanes(IGVs). The experimental study was conducted in a unique icing research tunnel available at Iowa State University (i.e., ISU-IRT). A hollowed IGV model embedded with U-shaped hot-air flowing conduit was designed and manufactured for the experimental investigations. During the experiments, while a high-speed imaging system was used to record the dynamic ice accretion or anti-/de-icing process over the surface of the IGV model for the test cases without and with the hot-air supply system being turned on, the corresponding surface temperature distributions on the IGV model were measured quantitatively by using a row of embedded thermocouples.
Technical Paper

An Experimental Study on the Effects of the Layout of DBD Plasma Actuators on Its Anti-/De-Icing Performance for Aircraft Icing Mitigation

2019-06-10
2019-01-2033
Recently developed dielectric barrier discharge (DBD) plasma-based anti-icing systems have shown great potential for aircraft icing mitigation. In the present study, the ice accretion experiments were performed on to evaluate the effects of different layouts of DBD plasma actuators on their anti-/de-icing performances for aircraft icing mitigations. An array of DBD plasma actuators were designed and embedded on the surface of a NACA0012 airfoil/wing model in different layout configurations (i.e., different alignment directions of the plasm actuators (e.g., spanwise vs. streamwise), width of the exposed electrodes and the gap between the electrodes) for the experimental study. The experimental study was carried out in the Icing Research Tunnel available at Iowa State University (i.e., ISUIRT).
Technical Paper

A Parametric Study on the Thermodynamic Characteristics of DBD Plasma Actuation and Its Potential for Wind Turbine Icing Mitigation

2019-06-10
2019-01-2031
Wind turbine icing represents the most significant threat to the integrity of wind turbines in cold weather. Ice formation on wind turbine blades was found to cause significant aerodynamic performance degradation, resulting in a substantial drop in energy production. Recently developed Dielectric barrier discharge (DBD) plasma-based anti-/de-icing systems showed very promising effects for aircraft icing mitigation. In this present study, DBD plasma-based anti-/de-icing systems were employed for wind turbine icing mitigation. First, a comprehensive parametric study is conducted to investigate the effects of various DBD plasma actuation parameters on its thermodynamic characteristics. An infrared (IR) thermal imaging system is used to quantitatively measure the temperature distributions over the test plate under various test conditions.
Technical Paper

SLD and Ice Crystal Discrimination with the Optical Ice Detector

2019-06-10
2019-01-1934
In response to new safety regulations regarding aircraft icing, Collins Aerospace has developed and tested an Optical Ice Detector (OID) capable of discriminating among icing conditions appropriate to Appendix C and Appendix O of 14 CFR Part 25 and Appendix D of Part 33. The OID is a short-range, polarimetric lidar that samples the airstream up to ten meters beyond the skin of the aircraft. The intensity and extinction of the backscatter light correlate with bulk properties of the cloud, such as water content and phase. Backscatter scintillation (combined with the outside air temperature from another probe) signals the presence of supercooled large droplets (SLD) within the cloud-a capability incorporated into the OID to meet the requirements of Appendix O. Recent laboratory and flight tests of the Optical Ice Detector have confirmed the efficacy of the OID to discriminate among the various icing conditions.
Technical Paper

Wind Tunnel Measurements of Simulated Glaciated Cloud Conditions to Evaluate Newly Developed 2D Imaging Probes

2019-06-10
2019-01-1981
Instrumentation that has been used for characterization of mixed-phase and glaciated conditions in the past, like the OAP probes, are subject to errors caused by variations in diffraction on the images away from the object plane and by the discrete nature of their particle detection and sizing. Correction methods are necessary to consider their measurements adequate for high ice water content (IWC) environments judged to represent a significant safety hazard to propellers and turbofan engine operability and performance. For this reason, within the frame of EU FP7 HAIC project, instrumentation characterization and validation is considered a major element need for successful execution of flight tests campaigns. Clearly, instrumentation must be sufficiently reliable to assess the reproducibility of artificial clouds with high ice water content generated in icing tunnels.
Technical Paper

The North Dakota Citation Research Aircraft Measurement Platform

2019-06-10
2019-01-1990
The North Dakota Citation Research Aircraft is a Cessna Citation II twin-engine fan-jet aircraft modified to be an atmospheric research platform that has been used on many field projects since the 1970s. The typical sampling speed of the modified Citation II is 160 knots indicated air speed (IAS), with sampling at altitudes up to 12.1 km (40,000 ft). The Citation Research Aircraft was operated by the University of North Dakota (UND) for many years but is now operated by Weather Modification International (WMI) of Fargo, North Dakota. WMI and UND together provide a unique test facility that is capable of deploying a wide range of instrumentation. WMI has the experience to install the custom instrumentation required for a specific field project and the expertise to conduct the most demanding aircraft sampling, including thunderstorm in-situ measurements.
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