Form 9.B Project Summary






Project Title:

Emission tomography for non-intrusive

three-dimensional measurements of

density, temperature, and chemical

composition in rocket engine plumes

Technical Abstract (Limit 200 words)

This proposal presents an economical instrument

for making global measurements of density,

temperature, and constituent concentration of

rocket engine plumes. This innovative technique is

based on collecting emitted flame radiation from a

large number of viewing angles; the irradiance

depends on the integrated effects of gas and

particulate temperature and species concentration

along the optical path. Using a large number of

intersecting optical paths allows the resulting set of

radiative transfer equations to be inverted to obtain

the spatial temperature profile of the flame or

plume. This emission tomography approach is

appealing because, unlike conventional

transmission tomography, neither probe beams nor

their associated optics are required. Therefore,

only simple optical access to the combustion

chamber is required to implement this technique.

Emission tomography can be used with both

stimulated and spontaneously emitted radiation,

and spectroscopic methods may be used to isolate

the concentration of one or more constituents. By

using two emission lines of a known species, the

temperature may be extracted by a simple two color

technique. Prior simulations and experiments

presented here illustrate that with simple optical

geometry and a single camera, the reaction zone of

a diffusion flame may be accurately identified; this

illustration applies equally well to temperature

measurement. Iterative algorithms are necessary to

account for self-absorption and refraction effects.

This technique may also be applied directly to other

gas phase processes.

Potential Commercial Applications (Limit 200 words)

The proposed instrument will provide three

dimensional density, temperature, and constituent

concentration measurements using spectroscopic

emission computed tomography. This instrument

will be useful in both research and industrial

monitoring applications, having applications in

areas requiring three dimensional measurement.

Significant applications include high temperature

gas dynamics, welding, plasma spray, and other gas

phase flows.

Name and Address of Principal Investigator (Name,

Organization Name, Mail Address, City/State/Zip)

Timothy D. Upton

Northeast Photosciences, Inc.

18 Flagg Rd.

Hollis , NH 03049

Name and Address of Offeror (Firm Name, Mail Address,


Paul Bagley

Northeast Photosciences, Inc.

18 Flagg Road

Hollis , NH 03049