Techniques have been developed for measuring the
temperature, stable species concentrations, and atomic
radical concentrations during a transient combustion
event. They combine the features of direct sampling with
two spectroscopic techniques to produce relatively simple
diagnostic techniques to obtain time-resolved
measurements. In this study, a transient event was
When trace quantities of an alkali element are added to a flame,
its optical and electrical properties change significantly. Addition of
alkali seed to both premixed and diffusion flames has been used in the
development of two new techniques, one for flame temperature measurement
and the other for enhanced mixing....
A continuous process for the production of ceramic materials has been studied.
This method reacted metal and oxidizer in a diffusionally controlled process,
demonstrated by reacting a magnesium particle stream and hot water vapor. Many small
rich hydrogen/air diffusion flames provide an atmosphere of hot water vapor, hydrogen,
A resonantly-coupled α-Stirling (RCAS) cooler was designed and constructed.
Tests on air and helium were performed with constant driving displacement over a range
of frequencies. The effects of changing driving amplitude and charged pressure were
The use of stainless steel bellows in place of pistons eliminated the problem of...
A phase sensitive measurement technique that permits the simultaneous determination
of two independent thermal properties of thin dielectric films is presented. Applying the technique results in a film's thermal diffusivity and effusivity, from which the thermal conductivity and specific heat can be calculated. The technique involves measuring a specimen's front...
A computational model for a resonantly coupled alpha free-piston Stirling cooler
is presented. The cooler consists of two isothermal working spaces for compression and
expansion connected by a regenerator consisting of a stack of narrow parallel channels.
The regenerator is assumed to have a linear temperature distribution along its axial...
A miniature reciprocating expander is being developed as part of a larger program
to develop a heat actuated heat pump for portable applications. By utilizing the higher
energy density of liquid hydrocarbon fuels relative to batteries, a heat actuated heat pump
would be able to provide cooling for much longer...
The use of a permeable membrane to mechanically constrain a film of water with an area of 12 cm² and a thickness of 150 μm in a gas/liquid contactor was investigated. The membrane separated the vapor and liquid phases, and a stiffener
plate made from a gas-permeable material was used...
A unique channel surface enhancement technique via diffusion-bonding a layer of
conductive fine wire mesh onto the heating wall was developed and used to
experimentally study flow boiling enhancement in parallel microchannels. Each
channel was 1000 μm wide and 510 μm high. A dielectric working fluid, HFE
7000, was used...
Hot engine exhaust and industrial process exhaust represents a resource that is often rejected to the environment without further utilization. This resource is prevalent in the transportation and industrial process sectors, but stationary engine-generator systems also typically do not utilize this resource. Engine exhaust is considered high grade heat and...