Application of a Fiber Optic Probe to High Void Fraction Air/Water Flow

2008 ◽  
Author(s):  
A. J. Pertzborn ◽  
W. C. Smith
Keyword(s):  
Size Distribution ◽  
Water Flow ◽  
Void Fraction ◽  
Droplet Size ◽  
Fiber Optic ◽  
Droplet Size Distribution ◽  
Spray Nozzle ◽  
Fiber Optic Probe ◽  
Flow Measurements ◽  
Optic Probe

Successful development of CFD models for droplet flows is aided by knowledge of the droplet size distribution in the flow, but current instrumentation for measuring droplet size is limited. In an attempt to improve the quality of data collected, fiber optic probe (FOP) technology was investigated. A spray nozzle injected water droplets into an air stream to create a high void fraction droplet flow. Measurements were acquired with the spray nozzle at two different locations upstream of the FOP position. Mean droplet velocity measurements were acquired using laser Doppler velocimetry (LDV) at the FOP position. The droplet size distribution at the probe location was determined by using both the FOP and LDV measurements. The initial results indicate that FOP technology can successfully measure the droplet size distribution in a high void fraction air/water flow and it should be further developed for this application.

Measurements of void fraction and bubble properties on a stepped chute using a fiber-optic probe

2005 ◽  
Vol 32 (4) ◽  
pp. 636-643 ◽  
Author(s):  
M K EL-Kamash ◽  
M R Loewen ◽  
N Rajaratnam
Keyword(s):  
Void Fraction ◽  
Bubble Size ◽  
Fiber Optic ◽  
Air Entrainment ◽  
Bubble Velocity ◽  
Fiber Optic Probe ◽  
Sample Rate ◽  
Optic Probe ◽  
Bubble Sizes ◽  
Stepped Chute

This paper presents results from an experimental laboratory study conducted to investigate the use of a fiber-optic probe for measuring void fraction, bubble sizes, and bubble velocities in the highly aerated flow generated over a stepped chute. The accuracy of the measurements was verified by comparing the discharge measured by using a magnetic flow meter with the integrated discharge computed from the time averaged void fraction and bubble velocity measurements. At a sample rate of 20 kHz the average errors in the void fraction, bubble velocity, and bubble size were estimated to be 1%, 5%, and 6%, respectively. Increasing the data sample rate reduces the errors in the bubble size and velocity. It was concluded that this fiber-optic probe is well suited for making measurements of the void fraction, bubble sizes, and bubble velocities in a unidirectional two-phase flow.Key words: stepped chute, jet flow, air entrainment, fiber-optic probe, air bubble.

Synthesis, performance and growth mechanism of silver nanoparticle coated SERS fiber probe

2019 ◽  
Vol 107 (3) ◽  
pp. 305
Author(s):  
Mengmei Geng ◽  
Yuting Long ◽  
Tongqing Liu ◽  
Zijuan Du ◽  
Hong Li ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Absorption Spectrum ◽  
Reaction Time ◽  
Growth Mechanism ◽  
Fiber Optic ◽  
Fiber Optic Probe ◽  
Visible Absorption ◽  
Fiber Probe ◽  
Surface Enhanced Raman ◽  
Optic Probe

Surface-enhanced Raman Scattering (SERS) fiber probe provides abundant interaction area between light and materials, permits detection within limited space and is especially useful for remote or in situ detection. A silver decorated SERS fiber optic probe was prepared by hydrothermal method. This method manages to accomplish the growth of silver nanoparticles and its adherence on fiber optic tip within one step, simplifying the synthetic procedure. The effects of reaction time on phase composition, surface plasmon resonance property and morphology were investigated by X-ray diffraction analysis (XRD), ultraviolet-visible absorption spectrum (UV-VIS absorption spectrum) and scanning electron microscope (SEM). The results showed that when reaction time is prolonged from 4–8 hours at 180 °C, crystals size and size distribution of silver nanoparticles increase. Furthermore, the morphology, crystal size and distribution density of silver nanoparticles evolve along with reaction time. A growth mechanism based on two factors, equilibrium between nucleation and growth, and the existence of PVP, is hypothesized. The SERS fiber probe can detect rhodamin 6G (R6G) at the concentration of 10−6 M. This SERS fiber probe exhibits promising potential in organic dye and pesticide residue detection.

MODELING DROPLET SIZE DISTRIBUTION NEAR A NOZZLE OUTLET IN AN ICING WIND TUNNEL

2006 ◽  
Vol 16 (6) ◽  
pp. 673-686 ◽  
Author(s):  
Laszlo E. Kollar ◽  
Masoud Farzaneh ◽  
Anatolij R. Karev
Keyword(s):  
Wind Tunnel ◽  
Size Distribution ◽  
Droplet Size ◽  
Droplet Size Distribution ◽  
Nozzle Outlet
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