Particle velocity measurement in powder gas jets of coaxial powder nozzles for laser material deposition

2021 ◽  
Vol 33 (1) ◽  
pp. 012019
Author(s):  
Jonathan Schaible ◽  
Luis Andrea Hau ◽  
David Weber ◽  
Thomas Schopphoven ◽  
Constantin Häfner ◽  
...  
Keyword(s):  
Particle Velocity ◽  
Velocity Measurement ◽  
Laser Material ◽  
Gas Jets ◽  
Material Deposition ◽  
Particle Velocity Measurement

scholarly journals Particle Velocity Measurement In Swirl Flow, Laboratory Studies

1970 ◽  
Vol 8 (1) ◽  
pp. 1-14
Author(s):  
Hari Prasad Neopane ◽  
Bhola Thapa ◽  
Ole Gunnar Dahlhaug
Keyword(s):  
Particle Velocity ◽  
Velocity Measurement ◽  
Guide Vane ◽  
Critical Diameter ◽  
Swirl Flow ◽  
Operating Conditions ◽  
Francis Turbine ◽  
Laboratory Studies ◽  
Test Rig ◽  
Particle Velocity Measurement

This paper presents the laboratory studies of particle velocity measurement in highly swirl conditions similar to turbine flow in curved path. It includes a brief description of the developed test rig, concept of critical diameter of particle inside a Francis turbine and experimental analysis. When a particle is flowing in swirl flow, drag force and centrifugal force are two major forces influencing the particle equilibrium. The equilibrium of these two forces provides a critical diameter of the particle. While, a particle larger than the critical diameter move away from the centre and hit the wall, a particle smaller than the critical diameter flows along with the water, and ultimately sinks. For critical diameter, the particle continues to rotate in the turbine. Different shapes and sizes of particles were tested with the same operating conditions and found that triangularly shaped particles were more likely to hit the suction side of the guide vane cascade. Furthermore, this study supports the concept of separation of particles from streamlines inside the test rig, which led to the development of an operating strategy for a Francis turbine processing sediment-laden water. This study also permitted experimental verification of the size and the shape of a particle as it orbits in the turbine, until either the velocity components are changed or the particle became smaller.DOI: http://dx.doi.org/10.3126/kuset.v8i1.6034 KUSET 2012; 8(1): 1-14

Powder Particle Velocity Measurement in Electrothermal Chemical Spraying Device

2000 ◽  
Author(s):  
L. Rabani ◽  
S. Wald ◽  
G. Appelbaum ◽  
D. Zoler
Keyword(s):  
Powder Particle ◽  
Particle Velocity ◽  
Velocity Measurement ◽  
High Speed ◽  
Diagnostic System ◽  
Rotating Disk ◽  
Coating Technology ◽  
Spot Center ◽  
Parallel Disks ◽  
Particle Velocity Measurement

Abstract A powder velocity diagnostic system in ElectroThermal Chemical Spray (ETCS) coating technology has been developed. The powder velocity is a crucial variable that influences the coating quality. However, non-of the existing methods is suitable for the velocity measurement in the special conditions of the ETCS technology. The proposed diagnostic system is based on a familiar technique called Double Rotating Disk. It measures the powder particle time-of-flight between two parallel disks. The disks are rotated by a high-speed motor. The front disk has holes distributed on its circumference. Particles passing a hole are deposited on the second disk. The displacement between the position of the deposited particles spot center and projection of the hole center on the second disk is inversely proportional to the velocity. The method allows the measurement of particle velocity with accuracy better than 10%. The results are in a good agreement with theoretical model predictions. The method is able, also, to observe the powder deposition rate and the particles spatial distribution inside the powder cloud according to their dimensions as a function of time during the coating process.

scholarly journals Comparison of particle velocity measurement techniques in a fluidized bed operating in the square-nosed slugging flow regime

2016 ◽  
Vol 296 ◽  
pp. 45-52 ◽  
Author(s):  
Sina Tebianian ◽  
Kristian Dubrawski ◽  
Naoko Ellis ◽  
Ray A. Cocco ◽  
Roy Hays ◽  
...  
Keyword(s):  
Flow Regime ◽  
Fluidized Bed ◽  
Particle Velocity ◽  
Velocity Measurement ◽  
Measurement Techniques ◽  
Particle Velocity Measurement
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