scholarly journals Optical and Energetic Investigation of an Advanced Corona Ignition System in a Pressure-Based Calorimeter

2020 ◽  
Vol 197 ◽  
pp. 06019
Author(s):  
Valentino Cruccolini ◽  
Gabriele Discepoli ◽  
Federico Ricci ◽  
Carlo Nazareno Grimaldi ◽  
Alessio Di Giuseppe
Keyword(s):  
Thermal Energy ◽  
High Speed ◽  
Operating Conditions ◽  
High Speed Camera ◽  
Ignition System ◽  
Excited Species ◽  
Electrode Voltage ◽  
Correct Determination ◽  
Speed Up

In recent years, radio-frequency corona igniters have been extensively studied for their capability to ensure an effective ignition also in lean or diluted mixtures. Corona ignition is volumetric, with streamers coming from a star-shaped electrode. During the discharge, many radicals and excited species, able to speed up the combustion onset, are generated. At the same time, corona igniters are able to release a considerable amount of thermal energy inside the combustion chamber. The correct determination of such energy is crucial to evaluate the effectiveness of the ignition. In this work, corona discharge is experimentally evaluated inside an optical vessel. In this apparatus, the released thermal energy is measured by means of pressure-based calorimetry, and at the same time the natural luminosity of the streamers is recorded with a high-speed camera. The goal is to find a relationship between thermal energy release and streamers luminosity. Tests are performed using nitrogen as medium, at different pressure levels inside the vessel. The peak electrode voltage is varied to characterize the igniter behaviour in different operating conditions. The results of this work can be used to quantify the corona ignition capabilities to involve a wide amount of medium while releasing a high amount of thermal energy. A repeatability evaluation of streamer evolution is investigated as well.

scholarly journals Crack Propagation Velocity Determination by High-speed Camera Image Sequence Processing

2020 ◽  
Author(s):  
Frank Liebold ◽  
Ali A. Heravi ◽  
Oliver Mosig ◽  
Manfred Curbach ◽  
Viktor Mechtcherine ◽  
...  
Keyword(s):  
Crack Propagation ◽  
High Speed ◽  
Vector Fields ◽  
Displacement Vector ◽  
Image Sequence ◽  
High Speed Camera ◽  
Sequence Processing ◽  
Image Sequence Processing ◽  
Propagation Velocities

The determination of crack propagation velocities can provide valuable information for a better understanding of damage processes of concrete. The spatio-temporal analysis of crack patterns developing at a speed of several hundred meters per second is a rather challenging task. In the paper, a photogrammetric procedure for the determination of crack propagation velocities in concrete specimens using high-speed camera image sequences is presented. A cascaded image sequence processing which starts with the computation of displacement vector fields for a dense pattern of points on the specimen’s surface between consecutive time steps of the image sequence chain has been developed. These surface points are triangulated into a mesh, and as representations of cracks, discontinuities in the displacement vector fields are found by a deformation analysis applied to all triangles of the mesh. Connected components of the deformed triangles are computed using region-growing techniques. Then, the crack tips are determined using principal component analysis. The tips are tracked in the image sequence and the velocities between the time stamps of the images are derived. A major advantage of this method as compared to established techniques is in the fact of its allowing for spatio-temporally resolved, full-field measurements rather than point-wise measurements and that information on crack width can be obtained simultaneously. To validate the experimentation, the authors processed image sequences of tests on four compact-tension specimens performed on a split-Hopkinson tension bar. The images were taken by a high-speed camera at a frame rate of 160,000 images per second. By applying to these datasets the image sequence processing procedure as developed, crack propagation velocities of about 800 m/s were determined with a precision in the order of 50 m/s.

Preliminary studies of the initial segments of the trajectory of a shell shot load fired from a 12 calibre shotgun

2016 ◽  
Vol 292 ◽  
pp. 78-81
Author(s):  
Grzegorz Bogiel ◽  
◽  
Krzysztof Ćwik ◽  
Keyword(s):  
High Speed ◽  
High Speed Camera ◽  
Forensic Examination ◽  
The Creation ◽  
Determination Of Parameters

12 calibre guns and ammunition can be subjected to forensic examination, often there is a need to determine the distance a shot was fired. The article presented a new way to carry out such studies and focused on visualization and the determination of parameters forming a fired, shot cluster. The examination uses a high-speed camera and software for the analysis of the recorded films. As a result of the research dimensions and speed of the creation of a cluster of fired shot were achieved.

Determination of frequencies of oscillations of cloud cavitation on a 2-D hydrofoil from high-speed camera observations

2016 ◽  
Vol 28 (3) ◽  
pp. 369-378 ◽  
Author(s):  
Patrik Zima ◽  
Tomáš Fürst ◽  
Milan SedláŘ ◽  
Martin Komárek ◽  
Rostislav Huzlík
Keyword(s):  
High Speed ◽  
High Speed Camera ◽  
Cloud Cavitation

scholarly journals NUMERICAL SIMULATION OF COOLING JET FROM HYDROGEN AND DEUTERIUM AS APPLICABLE TO INSTALLATIONS ON RECEIVING CRYOGENIC MONODISPERSE TARGETS

2019 ◽  
Vol 46 (1) ◽  
pp. 8-18
Author(s):  
A. V. Bukharov ◽  
A. F. Ginevsky ◽  
E. V. Vishnevsky
Keyword(s):  
High Speed ◽  
Low Pressure ◽  
Numerical Calculations ◽  
Liquid Jets ◽  
Temperature Changes ◽  
Working Chamber ◽  
Pressure Area ◽  
Speed Up ◽  
Determination Of Parameters

Objectives. Development of a model and carrying out numerical calculations for the cooling of thin jets of Hydrogen and Deuterium as applicable to installations on receiving cryogenic monodisperse targets.Methods. To achieve this purpose, the model of cryogenic jet outflow into the low pressure area was created and using PHOENICS software the temperature change of the surface and the interior of a jet over time for various external parameters is investigated through the numerical method.Result. The dependences of temperature changes of liquid Hydrogen and Deuterium jets along the jet surface and along the radius depending on the jet diameter, speed, initial jet temperature and pressure in the working chamber of installations for receiving cryogenic monodisperse targets were carried out.Conclusion. The principal possibility of creating high-speed cryogenic monodisperse targets is shown. According to the calculations, at input of thin liquid jets of Hydrogen or Deuterium with a speed up to 100 m/s into the working chamber with low pressure, jets at a distance of up to 1 mm do not have time to freeze and can be broken into monodisperse drops. Drops are cooled due to evaporation and become granules. The developed model, the program for determination of parameters of steady monodisperse disintegration of liquid cryogenic streams and results of numerical calculations can be used during creation of units for receiving high-speed cryogenic monodisperse targets.

scholarly journals Palm H-FAME Production through Partially Hydrogenation using Nickel/Carbon Catalyst to Increase Oxidation Stability

2018 ◽  
Vol 156 ◽  
pp. 03004
Author(s):  
Elsa Ramayeni ◽  
Bambang Heru Susanto ◽  
Dimas Firlyansyah Pratama
Keyword(s):  
Oxidation Stability ◽  
Acid Methyl Ester ◽  
Operating Conditions ◽  
Injection System ◽  
Empirical Measure ◽  
Partial Hydrogenation ◽  
Carbon Catalyst ◽  
Pump System ◽  
Speed Up

One of the methods to improve the oxidation stability of palm biodiesel is through partially hydrogenation. The production using Nickel/Carbon catalyst to speed up the reaction rate. Product is called Palm H-FAME (Hydrogenated FAME). Partial hydrogenation breaks the unsaturated bond on FAME (Fatty Acid Methyl Ester), which is a key component of the determination of oxidative properties. Changes in FAME composition by partial hydrogenation are predicted to change the oxidation stability so it does not cause deposits that can damage the injection system of diesel engine, pump system, and storage tank. Partial hydrogenation is carried out under operating conditions of 120 °C and 6 bar with 100:1, 100:3, 100:5, 100:10 % wt catalyst in the stirred batch autoclave reactor. H-FAME synthesis with 100:5 % wt Ni/C catalyst can decrease the iodine number which is the empirical measure of the number of unsaturated bonds from 91.78 to 82.38 (g-I2/100 g) with an increase of oxidation stability from 585 to 602 minutes.

scholarly journals Crack Propagation Velocity Determination by High-speed Camera Image Sequence Processing

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4415
Author(s):  
Frank Liebold ◽  
Ali A. Heravi ◽  
Oliver Mosig ◽  
Manfred Curbach ◽  
Viktor Mechtcherine ◽  
...  
Keyword(s):  
Crack Propagation ◽  
High Speed ◽  
Vector Fields ◽  
Displacement Vector ◽  
Image Sequence ◽  
High Speed Camera ◽  
Sequence Processing ◽  
Image Sequence Processing ◽  
Propagation Velocities

The determination of crack propagation velocities can provide valuable information for a better understanding of damage processes of concrete. The spatio-temporal analysis of crack patterns developing at a speed of several hundred meters per second is a rather challenging task. In the paper, a photogrammetric procedure for the determination of crack propagation velocities in concrete specimens using high-speed camera image sequences is presented. A cascaded image sequence processing which starts with the computation of displacement vector fields for a dense pattern of points on the specimen’s surface between consecutive time steps of the image sequence chain has been developed. These surface points are triangulated into a mesh, and as representations of cracks, discontinuities in the displacement vector fields are found by a deformation analysis applied to all triangles of the mesh. Connected components of the deformed triangles are computed using region-growing techniques. Then, the crack tips are determined using the principal component analysis. The tips are tracked in the image sequence and the velocities between the time stamps of the images are derived. A major advantage of this method as compared to the established techniques is in the fact that it allows spatio-temporally resolved, full-field measurements rather than point-wise measurements. Furthermore, information on the crack width can be obtained simultaneously. To validate the experimentation, the authors processed image sequences of tests on four compact-tension specimens performed on a split-Hopkinson tension bar. The images were taken by a high-speed camera at a frame rate of 160,000 images per second. By applying the developed image sequence processing procedure to these datasets, crack propagation velocities of about 800 m/s were determined with a precision in the order of 50 m/s.

Spatiotemporal Distribution of Soot Temperature for Flames Using Optical Pyrometry Under Unsteady Inlet Airflow Conditions

2016 ◽  
Vol 139 (5) ◽  
Author(s):  
Arda Cakmakci ◽  
Michael Knadler ◽  
Jong Guen Lee
Keyword(s):  
Temperature Fluctuation ◽  
High Speed ◽  
Flame Temperature ◽  
Temperature Response ◽  
Operating Conditions ◽  
Local Temperature ◽  
Soot Temperature ◽  
High Speed Camera ◽  
Unsteady Combustion ◽  
Inlet Velocity

Two pyrometric tools for measuring soot temperature response in fuel-rich flames under unsteady inlet airflow conditions are developed. High-speed pyrometry using a high-speed color camera is used in producing soot temperature distributions, with its results compared with those of global soot temperature response measured using a multiwavelength pyrometer. For the former, the pixel red, green, and blue (RGB) values pertaining to respective bandwidths of red, green, and blue filters are used to calculate temperature and for the latter, the emission from whole flame at 660 nm, 730 nm, and 800 nm is used to measure temperature. The combustor, running on jet-A fuel, achieves unsteady inlet airflow using a siren running at frequencies of 150 and 250 Hz and with modulation levels (root mean square (RMS)) 20–50% of mean velocity. Spatiotemporal response of flame temperature measured by the high-speed camera is presented by phase-averaged with average subtracted images and by fast Fourier transform (FFT) at the modulation frequencies of inlet velocity. Simultaneous measurement of combustor inlet air velocity and flame soot temperature using the multiwavelength pyrometer is used in calculating the flame transfer function (FTF) of flame temperature response to unsteady inlet airflow. The results of global temperature and temperature fluctuation from the three-color pyrometer show qualitative agreement with the local temperature response measured by the high-speed camera. Over the range of operating conditions employed, the overall flame temperature fluctuation increases linearly with respect to the inlet velocity fluctuation. The two-dimensional map of flame temperature under unsteady combustion determined using a high-speed digital color camera shows that the local temperature fluctuation during unsteady combustion occurs over relatively small region of flame and its level is greater (∼10% to 20%) than that of overall temperature fluctuation (∼1%).

Investigation of Contact Characteristics of Long-Fiber Reinforced Plastic Gears Based on Observation With a High-Speed Camera

2010 ◽  
Author(s):  
Tomoki Otawa ◽  
Toshiski Hirogaki ◽  
Eiichi Aoyama
Keyword(s):  
Temperature Distribution ◽  
High Speed ◽  
Gear Tooth ◽  
Dynamic Contact ◽  
Operating Conditions ◽  
Back Surface ◽  
High Speed Camera ◽  
Contact Ratio ◽  
Contact State ◽  
Plastic Gears

We also observed the dynamic contact state of gear meshing in operating conditions with a high-speed camera. The temperature distribution when driving was measured by thermography. Contact ratio is often used to show contact state, but there are currently no reports that describe the dynamic contact ratio of FRP gears although there are some reports on plastic gears. We therefore considered a contact ratio formula based on a new contact model that the dynamic real deflections of the gear tooth. The temperature distribution measurement was done from the side and the upper surface of the gear. The characteristics of heat generation on the surface of each gear tooth were analyzed, and the temperature distribution was analyzed according to the time and each point of the tooth. (1) FRP gears over heated as a result of driving by the metal gear for a long time. The rise in temperature was rapid and was compounded by heat dissipated from the metal gear. (2) The pitch point of the FRP gear tooth had the highest temperature. The reason for this is that the hysteresis heating is large. It is not easy for the gear to dissipate heat. (3) The temperature rose as a result of hysteresis heating. At high torque, the back surface contact and deflection of the teeth also increased because the gear became viscoelastic.

scholarly journals DETERMINATION OF DYNAMIC LOADS IN TRANSMISSIONS TRACKED FOREST MACHINE WHILE OVERCOMING OBSTACLES

2017 ◽  
Vol 7 (1) ◽  
pp. 185-196
Author(s):  
Клубничкин ◽  
Vladislav Klubnichkin ◽  
Клубничкин ◽  
Evgeniy Klubnichkin ◽  
Бухтояров ◽  
...  
Keyword(s):  
High Speed ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Dynamic Loads ◽  
Pilot Studies ◽  
Torque Transmission ◽  
Characteristic Species ◽  
Final Drive

The theoretical analysis of dynamic phenomena in transmission tracked forest machine is much more difficult in the absence of experimental data on the effects of the input characteristic of the machine. The most characteristic species in the transmission effects that arise under real operating conditions allow to evaluate the results of experimental studies, they also provide an opportunity to assess the quality of theoretical studies. To determine the loading of the transmission in the experiment involves the measurement of a number of kinematic and power parameters characterizing the speed and stress state of the transmission. In the course of the research used a special measuring equipment made in Germany includes the high-speed digital telemetry system for strain "TEL1-PCM-HS" company KMT. This article describes how to determine the dynamic load transmission elements tracked forest machine LZ-5 in overcoming individual barriers in experimental studies (tests). The paper presents a program of pilot studies tracked forest machine. Presented curves change the time settings on the final drives and cardan shaft, depending on the speed of the engine and drive sprockets in overcoming obstacles GLZM with different gears. histograms were constructed on the distribution of the torque transmission shafts for various modes of overcoming obstacles in order to analyze the influence of operational factors on the magnitude of dynamic loads. The article presents the distribution curve of the moments on the driven shaft final drive to overcome obstacles tracked forest machine with a pack assortments in the volume of 12m3. It was noted that there are no less than 20 times the dynamic point values, which exceed the estimated time for the overcoming of obstacles. From the studies that the transmission level of at least dynamic forces having height obstacles.

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