Measurement of Size and Velocity of Arbitrarily Shaped Particles by LDA Based Shadow Image Technique

Morikita, Hiroshi; Hishida, Koichi; Maeda, Masanobu

doi:10.1007/978-3-642-79965-5_24

Cited by 10 publications

(12 citation statements)

References 7 publications

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“…Figure 5 is a scatter diagram of the relationship between the size and velocity of flying liquid droplets, which were sprayed out from the RAC nozzle, as measured using a shadow Doppler particle analyzer (SDPA). 14) The measurement conditions were a rotational speed of the air turbine of 50,000 min À1 , a shaping air pressure of 0.4 MPa, a flow rate of 100 ml/min, and a distance from the surface of the wafer and the end of the cup to the measuring point of 10 mm. Figure 6 shows the velocity distribution, which had mean of 65.7 m/s and a standard deviation of 11.4 m/s.…”

Section: Trial System and Characteristics Of Flying Liquid Dropletsmentioning

confidence: 99%

Silicon Wafer Cleaning Using New Liquid Aerosol with Controlled Droplet Velocity and Size by Rotary Atomizer Method

Seike¹,

Miyachi

Shibata³

et al. 2010

Jpn. J. Appl. Phys.

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Numerical experiments on two-dimensional convection with or without a vertical magnetic field reveal a bewildering variety of periodic and aperiodic oscillations. Steady rolls can develop a shearing instability, in which rolls turning over in one direction grow at the expense of rolls turning over in the other, resulting in a net shear across the layer. As the temperature difference across the fluid is increased, two-dimensional pulsating waves occur, in which the direction of shear alternates. We analyse the nonlinear dynamics of this behaviour by first constructing appropriate low-order sets of ordinary differential equations, which show the same behaviour, and then analysing the global bifurcations that lead to these oscillations by constructing one-dimensional return maps. We compare the behaviour of the partial differential equations, the models and the maps in systematic two-parameter studies of both the magnetic and the non-magnetic cases, emphasizing how the symmetries of periodic solutions change as a result of global bifurcations. Much of the interesting behaviour is associated with a discontinuous change in the leading direction of a fixed point at a global bifurcation; this change occurs when the magnetic field is introduced.

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Section: Trial System and Characteristics Of Flying Liquid Dropletsmentioning

confidence: 99%

Silicon Wafer Cleaning Using New Liquid Aerosol with Controlled Droplet Velocity and Size by Rotary Atomizer Method

Seike¹,

Miyachi

Shibata³

et al. 2010

Jpn. J. Appl. Phys.

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“…Provided that the traj ectory li es within the a pprox imate angle range stated above, the SDY sig nal can also yield the angle of th e trajec to ry re lati ve to the ax is of the photodiode array [ 16]. By analys ing the measured ve locity o nto a Cartesian syste m, it was possible to derive two-d ime nsional ve locity info rmat io n form an effectively sing le channe l o ne-di me ns ional velocimeter with a tolerance no t exceed in g I 0% in th e mean, and 15 % in th e rms, ve loc ity and less than I 0% in the angle estimati o n. Following Figure 4b the in stant aneous velocity components u, v in a cartesian co-ord in ate system were obtained fro m:…”

Section: Measurement Strategymentioning

confidence: 99%

“…where ni was the nlllnber of measurements in size class i and A is the effective cross-section of the SDV probe volume which is a non-m onoton ic function with size, di: for its calcul ation, the reader is refened to Morikita et a !. [ 16].…”

Section: ~20mentioning

confidence: 99%

Shadow Doppler Velocimetry for Simultaneous Size and Velocity Measurements of Irregular Particles in Confined Reacting Flows

Maeda¹,

Morikita²,

Prassas³

et al. 1997

Part & Part Syst Charact

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We report the application of the Shadow Doppler Velocimeter (SDV) for spatial precise, simultaneous measurement of the size and velocity to assess the particle retention performance of a laboratory, 1/6 scale, 10 kW vertically‐fired atmospheric model of the pressurised pulverised‐coal furnace of Reichert et al. [1]. The SDV is based on the imaging of a conventional LDV probe volume onto a linear photodiode array and has the advantage over other sizing methods for irregular particles that it is tolerant of the optical misalignment and fouling which are inevitable when passing laser beams through windows in such furnaces. The size and two components of velocity of burning coal particles were measured in the present geometry which has 172 mm furnace diameter and 40 mm lateral exit duct diameter and a calculated exit bulk velocity of 4 m/s, evaluated at 300 K. The Sauter mean diameter of the particles is, within the experimental error, uniform at about 40 μm in the vertical profile normal to the axis of the exhaust pipe, 34.5 mm upstream of the exit. Coal particle velocities in the near‐exit region are directed towards the exit, closely following the gas‐phase velocities. Both these observations imply that particle retention efficiency due to streamline curvature is low and extrapolation suggests that there will be even less at large scales.

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“…The images of the particles are processed and analyzed at high particle velocities to find velocity, shape, orientation, and size of particles, regardless of their shape (spherical or nonspherical) and optical property such as refractive index and particle emissivity. The principle of the Shadow Doppler Particle Analyzer was given in detail by Morikita et al (1994Morikita et al ( , 1995, and the application of the SDPA continues to be an area of research. The objective of this study was to develop a laboratory in-line optical probe for the simultaneous determination of particle shape, size, and velocity in a solid particle-laden process flow.…”

Section: Introductionmentioning

confidence: 99%

Optical Probe for the In-Line Determination of Particle Shape, Size, and Velocity

Petrak

Rauh

2006

Particulate Science and Technology

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A laboratory optical probe was developed to simultaneously determine the following particle characteristics: circularity, particle projection area, equivalent diameter of a circle, length of the particle outline or perimeter, maximum chord length, aspect ratio, and particle velocity. Using the projection area and the perimeter, the particle shape factor circularity can be determined. The aspect ratio was approximated by the ratio of the equivalent diameter to the maximum chord length. The basic measuring principle is multi-point scanning of the particle shadow image by a line of optical fibers. In addition, the particle velocity can be measured by a differential spatial filter of optical fibers. These fibers are step index fibers with a core diameter of 64 mm and cladding of 70 mm. The shadow image of a single particle was generated by a parallel laser beam. The uncertainty of the measured circularity and aspect ratio was investigated by using metal wires with diameters of 0.12 to 0.5 mm as test particles with known circularity and aspect ratio. The standard deviations were 1.9% for the circularity and 15.5% for the approximated aspect ratio. In addition, the optical probe system was investigated by measurements of solid particles with different shapes. As an example, the results of sand, marjoram seed, and metallic oxide particles are shown. Using 1000 sand particles, the correlation between equivalent diameter and particle velocity could be demonstrated. The presented configuration of the optical probe is applicable in the size range of 0.1 to 0.9 mm and up to a particle velocity of 5 m=s.

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Measurement of Size and Velocity of Arbitrarily Shaped Particles by LDA Based Shadow Image Technique

Cited by 10 publications

References 7 publications

Silicon Wafer Cleaning Using New Liquid Aerosol with Controlled Droplet Velocity and Size by Rotary Atomizer Method

Silicon Wafer Cleaning Using New Liquid Aerosol with Controlled Droplet Velocity and Size by Rotary Atomizer Method

Shadow Doppler Velocimetry for Simultaneous Size and Velocity Measurements of Irregular Particles in Confined Reacting Flows

Optical Probe for the In-Line Determination of Particle Shape, Size, and Velocity

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