Liquid Film Thickness Measurements by Means of Internally Reflected Light

1995 ◽  
Author(s):  
Lawrence W. Evers ◽  
Kenneth J. Jackson
Keyword(s):  
Film Thickness ◽  
Liquid Film ◽  
Liquid Film Thickness ◽  
Reflected Light ◽  
Thickness Measurements

Fluorescence and Fiber-Optics Based Real-Time Thickness Sensor for Dynamic Liquid Films

2009 ◽  
Vol 132 (3) ◽  
Author(s):  
T. W. Ng ◽  
A. Narain ◽  
M. T. Kivisalu
Keyword(s):  
Film Thickness ◽  
Liquid Film ◽  
Fiber Optics ◽  
Calibration Procedure ◽  
Liquid Films ◽  
Flow Dynamics ◽  
Liquid Film Thickness ◽  
Fiber Optic Technology ◽  
Thickness Measurements ◽  
Film Flows

To overcome the limitations/disadvantages of many known liquid film thickness sensing devices (viz. conductivity probes, reflectance based fiber-optics probes, capacitance probes, etc.), a new liquid film thickness sensor that utilizes fluorescence phenomena and fiber-optic technology has been developed and reported here. Measurements from this sensor are expected to facilitate better understanding of liquid film dynamics in various adiabatic, evaporating, and condensing film flows. The sensor accurately measures the instantaneous thickness of a dynamically changing liquid film in such a way that the probe does not perturb the flow dynamics in the proximity of the probe’s tip. This is achieved by having the probe’s exposed surface embedded flush with the surface over which the liquid film flows, and by making arrangements for processing the signals associated with the emission and collection of light (in distinctly different wavelength windows) at the probe’s flush surface. Instantaneous film thickness in the range of 0.5–3.0 mm can accurately (with a resolution that is within ±0.09 mm over 0.5–1.5 mm range and within ±0.18 mm over 1.5–3.0 mm range) be measured by the sensor described in this paper. Although this paper only demonstrates the sensor’s ability for dynamic film thickness measurements carried out for a doped liquid called FC-72 (perfluorohexane or C6F14 from 3M Corporation, Minneapolis, MN), the approach and development/calibration procedure described here can be extended, under similar circumstances, to some other liquid films and other thickness ranges as well.

On liquid‐film thickness measurements with the atomic‐force microscope

1991 ◽  
Vol 95 (1) ◽  
pp. 706-708 ◽  
Author(s):  
Mikel L. Forcada ◽  
Mario M. Jakas ◽  
Alberto Gras‐Martí
Keyword(s):  
Film Thickness ◽  
Liquid Film ◽  
Atomic Force Microscope ◽  
Liquid Film Thickness ◽  
Atomic Force ◽  
Thickness Measurements

Liquid film thickness measurements on a plate based on brightness curve analysis with acute PLIF method

2021 ◽  
Vol 136 ◽  
pp. 103549
Author(s):  
Tianyu Li ◽  
Tianyou Lian ◽  
Bingyao Huang ◽  
Xiaoyuan Yang ◽  
Xunchen Liu ◽  
...  
Keyword(s):  
Film Thickness ◽  
Liquid Film ◽  
Curve Analysis ◽  
Liquid Film Thickness ◽  
Thickness Measurements ◽  
Brightness Curve

Fluorescence and Fiber-Optics Based Real-Time Thickness Sensor for Dynamic Liquid Films

2007 ◽  
Author(s):  
T. W. Ng ◽  
A. Narain
Keyword(s):  
Film Thickness ◽  
Liquid Film ◽  
Fiber Optics ◽  
Calibration Procedure ◽  
Liquid Films ◽  
Flow Dynamics ◽  
Liquid Film Thickness ◽  
Fiber Optic Technology ◽  
Thickness Measurements ◽  
Film Flows

To overcome the limitations/disadvantages of many known liquid film thickness sensing devices (viz. conductivity probes, reflectance based fiber-optics probes, capacitance probes, etc.), a new liquid film thickness sensor that utilizes fluorescence phenomena and fiber-optic technology has been developed and reported here. Measurements from this sensor are expected to facilitate better understanding of liquid film dynamics in various adiabatic, evaporating, and condensing film flows. The sensor accurately measures the instantaneous thickness of a dynamically changing liquid film in such a way that the probe does not perturb the flow dynamics in the proximity of the probe’s tip. This is achieved by having the probe’s exposed surface embedded flush with the surface over which the liquid film flows, and by making arrangements for processing the signals associated with the emission and collection of light (in distinctly different wavelength windows) at the probe’s flush surface. Instantaneous film thickness in the range of 0.5 to 3.0 mm can accurately (with a resolution that is within +/− 0.09 mm over 0.5 to 1.5 mm range and within +/− 0.18 mm over 1.5 to 3.0 mm range) be measured by the sensor described in this paper. Although this paper only demonstrates the sensor’s ability for dynamic film thickness measurements carried out for a doped liquid called FC-72 (perfluorohexane or C6F14 from 3M Corporation), the approach and development/calibration procedure described here can be extended, under similar circumstances, to some other liquid films as well.

Study on Liquid Film Thickness of Accelerated Slug Flow in Micro Tubes

2014 ◽  
Author(s):  
Kenshiro Muramatsu ◽  
Youngjik Youn ◽  
Youngbae Han ◽  
Keishi Yokoyama ◽  
Yosuke Hasegawa ◽  
...  
Keyword(s):  
Film Thickness ◽  
Liquid Film ◽  
Slug Flow ◽  
Liquid Film Thickness

Experimental comparison of the spray atomization of heavy and light fuel oil at different temperatures and pressures for pressure-swirl injector

2021 ◽  
pp. 095765092199437
Author(s):  
Elyas Rostami ◽  
Hossein Mahdavy Moghaddam
Keyword(s):  
Film Thickness ◽  
Liquid Film ◽  
Diesel Fuel ◽  
Temperature Increase ◽  
Liquid Film Thickness ◽  
Fuel Oil ◽  
Spray Angle ◽  
Breakup Length ◽  
Fuel Atomization ◽  
Mean Diameter

In this study, the atomization of heavy fuel oil (Mazut) and diesel fuel at different pressures is compared experimentally. Also, the effects of temperature on the Mazut fuel atomization are investigated experimentally. Mass flow rate, discharge coefficient, wavelength, liquid film thickness, ligament diameter, spray angle, breakup length, and sature mean diameter are obtained for the Mazut and diesel fuel. Fuels spray images at different pressures and temperatures are recorded using the shadowgraphy method and analyzed by the image processing technique. Error analysis is performed for the experiments, and the percentage of uncertainty for each parameter is reported. The experimental results are compared with the theoretical results. Also, Curves are proposed and plotted to predict changes in the behavior of atomization parameters. Diesel fuel has less viscosity than Mazut fuel. Diesel fuel has shorter breakup length, wavelength, liquid film thickness, and sature mean diameter than Mazut fuel at the same pressure. Diesel fuel has a larger spray angle and a larger discharge coefficient than Mazut fuel at the same pressure. As the pressure and temperature increase, fuel atomization improves. The viscosity of Mazut fuel is decreased by temperature increase. As the fuel injection pressure and temperature increase, breakup length, wavelength, liquid film thickness, and sature mean diameter decrease; also, spray angle increases.

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