Related Experiment Video
Updated: Jun 11, 2026
10:53
Simultaneous Measurement of Turbulence and Particle Kinematics Using Flow Imaging Techniques
Published on: March 12, 2019
Simultaneous velocity and pressure measurements using luminescent microspheres
Fletcher Kimura1, Jesse McCann, Gamal E Khalil
1Department of Chemistry, University of Washington, Seattle, Washington 98195, USA.
The Review of Scientific Instruments
|July 2, 2010
Summary
Researchers developed novel pressure-sensitive microspheres (PrSBeads) for precise 2D oxygen and pressure mapping in gas flows. These microspheres also enable simultaneous velocity measurements, advancing aerodynamic flow analysis.
Area of Science:
- Aerodynamics
- Optical Measurement Techniques
- Materials Science
Background:
- Quantitative oxygen and pressure measurements in dynamic gaseous flows are crucial for understanding complex aerodynamic phenomena.
- Existing methods often lack the spatial resolution or simultaneous multi-parameter measurement capabilities required for detailed flow analysis.
Purpose of the Study:
- To introduce and validate pressure-sensitive microspheres (PrSBeads) for simultaneous, quantitative, two-dimensional measurements of oxygen concentration and pressure in gaseous flows.
- To demonstrate the capability of PrSBeads in conjunction with digital particle image velocimetry (DPIV) for concurrent velocity measurements.
Main Methods:
- Modified rapid lifetime determination technique was employed for oxygen sensing using aerosolized PrSBeads.
- A charge-coupled device with a double image frame (DIF) feature was utilized for spatially resolved pressure measurements.
- Digital particle image velocimetry (DPIV) was applied for instantaneous velocity determination of airborne PrSBeads.
Main Results:
- PrSBeads achieved point measurement precisions of 0.1%-1% for oxygen concentration.
- Spatially resolved pressure measurements showed improved accuracy with larger pixel binning (0.003-0.005 atm error).
- Demonstrated ability to resolve oxygen gradients and measure instantaneous pressure changes, alongside simultaneous velocity measurements at 6.4 Hz.
Conclusions:
- PrSBeads are validated as a versatile tool for simultaneous, quantitative measurement of oxygen, pressure, and velocity in aerodynamic flows.
- The technique offers high precision and spatial resolution, enabling detailed characterization of complex gas dynamics.
- This advancement provides a novel approach for in-situ analysis in various fluid dynamics applications.
Related Concept Videos
01:25Fluorescence and Phosphorescence: Instrumentation
Fluorometers and spectrofluorometers are two types of instruments used for measuring molecular fluorescence. These instruments differ in how they select excitation and emission wavelengths and the type of light sources they utilize. Fluorometers use absorption interference filters to choose excitation and emission wavelengths. The excitation source in a fluorometer is typically a low-pressure mercury vapor lamp that emits intense lines distributed throughout the ultraviolet and visible regions.
01:14Photoluminescence: Applications
Photoluminescence offers a wide range of applications due to its inherent sensitivity and selectivity. This technique allows for both direct and indirect analyses of the analyte. Direct quantitative analysis is possible when the analyte exhibits a favorable quantum yield for fluorescence or phosphorescence. However, an indirect analysis may be feasible if the analyte is not fluorescent or phosphorescent, or if the quantum yield is unfavorable. Indirect methods include reacting the analyte with...