Fluorescent particles enable visualization of the flow patterns of gases at slow velocities. Through a transparent section in the gas line, a camera views the visible light emitted by the particles carried by the gas stream. Fine definition of the particle tracks are obtained at slow camera shutter speeds

Wilson, A. J.

English

NASA Technical Reports Server

July 1968	 Brief 68-10259 
NASA TECH BRIEF 
NASA Tech Briefs are issued to summarize specific innovations derived from the U.S. space program, 
to encourage their commercial application. Copies are available to the public at 15 cents each 
from the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Fluorescent Particles Enable Visualization of Gas Flow 
A simple method has been devised to provide a 
visual representation of the flow patterns of gases at 
velocities that are too slow for characterization by 
Schlieren photography. To apply this method, a trans-
parent section is first coupled into the gas line where 
the flow is to be observed. The gas stream is then 
infused with a commercially available, finely divided 
material that fluoresces under ultraviolet light (2537 
Angstroms). The ultraviolet light is directed into one 
side of the transparent section and a camera with high-
speed black and white ifim is set up to view the visible 
light emitted by the fluorescent particles carried by the 
gas stream. The observations are made in a darkened 
area (ambient lighting extinguished). Additionally, an 
ultraviolet blocking filter is used on the camera lens 
to eliminate any background reflections so as to ensure 
that the photographic image is due only to the fluores-
cent particles in the gas stream. Fine definition of the 
particle tracks (gas flow patterns) are obtained at slow 
(0.2- to 0.5-second) camera shutter speeds.
Notes: 
1. This method is a refinement of the photographic 
method of gas flow visualization using opaque-
particle tracers in conjunction with a continuous 
front light source and a strobe light, as described 
in Tech Brief 66-10668. 
2. Details may be obtained from: 
Technology Utilization Officer 
Marshall Space Flight Center 
Huntsville, Alabama 35812 
Reference: B68-10259 
Patent status: 
No patent action is contemplated by NASA. 
Source: A. J. Wilson
of North American Rockwell Corporation

under contract to

Marshall Space Flight Center
(MFS-14583) 
Category 02 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19680000259 2020-03-12T06:12:14+00:00Z


Fluorescent particles enable visualization of gas flow

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