Browse Prior Art Database

Air-Flow Visualization Using the Photoluminescence of Infrared-Sensitive Phosphor

IP.com Disclosure Number: IPCOM000120981D
Original Publication Date: 1991-Jul-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 77K

Publishing Venue

IBM

Related People

Crawforth, L: AUTHOR [+3]

Abstract

Disclosed is a technique based on the photoluminescence of infrared (IR)-sensitive phosphor to quantitatively determine air-flow velocity of extended regions in two dimensions. The novelty of this invention resides in the use of IR-sensitive phosphor, which may be turned on and off, to define an initial pattern in the flow at an initial time. The properties of the phosphor allow the flow-induced distortions of the initial pattern to be measured at a later, selected time.

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This is the abbreviated version, containing approximately 53% of the total text.

Air-Flow Visualization Using the Photoluminescence of Infrared-Sensitive
Phosphor

      Disclosed is a technique based on the photoluminescence
of infrared (IR)-sensitive phosphor to quantitatively determine
air-flow velocity of extended regions in two dimensions. The novelty
of this invention resides in the use of IR-sensitive phosphor, which
may be turned on and off, to define an initial pattern in the flow at
an initial time. The properties of the phosphor allow the
flow-induced distortions of the initial pattern to be measured at a
later, selected time.

      The IR-sensitive phosphor that is seeded into the flow belongs
to a special class of photoluminescent material that has a delayed
effect (Quantex Photonic Products, Rockville, MD).  When illuminated
with visible light, the material stores electrons in traps for very
long periods of time. The trapped electrons can be released at will
by illuminating the material with infrared radiation.  This causes
the material to fluoresce in the visible with a wavelength anywhere
from 500 to 650 nm depending on the specific material used.  The
phosphor may be obtained in sufficiently small particles (< 1 micron)
so that they effectively follow the flow.  The photoluminescent
material is well suited for quantitative flow measurements in that it
may be selectively charged and discharged, thus allowing flow
properties to be measured by two-dimensional time of flight
techniques.  The time- of-flight flow measurement tec...