Early History:
The phenomena of photoluminescence and oxygen quenching have been studied for many years. Peterson and Fitzgerald
were the first to propose the use of these phenomena as a flow visualization tool in 1980. They described an
experiment in which a surface was covered with a fluorescent dye that was then excited by a blue light. Once the
flow was turned on, either nitrogen or oxygen was injected into the flow through a static pressure tap on the
surface.
When nitrogen was injected, a bright streak of luminescence was observed downstream of the tap, due to decreased
oxygen quenching. When oxygen was injected, the increased oxygen quenching resulted in a dark streak downstream of
the tap. Unfortunately, the PSP used in this experiment was not very conducive to accurate and practical
experimental use. The oxygen sensitivity of the dye and the oxygen permeability of the binder were both
relatively low. In addition, the PSP layer was thick, rough, and didn't adhere to the surface very well.
Application of PSP:
The first research into PSP as a practical surface pressure field measurement was conducted during the early to
mid-1980s in the former Soviet Union at TsAGI/Moscow in cooperation with Moscow University. For a number of years,
the efforts of the Soviets in PSP research were not well known in the west, as the information was limited in its
distribution. In 1990, the existence of the Soviet PSP technology was revealed to a great extent through an
advertisement in Aviation Week & Space Technology magazine. This exposure was the start of a commercialization
effort towards the west.
In the United States, the feasibility of using PSP for surface pressure field measurement was demonstrated in 1989
at the NASA Ames Research Center using a coating developed at the University of Washington. Since then, research
has continued at NASA Ames, along with programs aimed specifically at aircraft development being conducted at
Boeing and McDonnell-Douglas Aerospace (which has since been acquired by Boeing). Other centers of PSP research
include the NASA Langley Research Center and the United States Air Force Arnold Engineering and Development
Center (AEDC).
