Fire Suppression Sprays
We made the first measurements of a fire sprinkler spray in the presence of a fire. The results have been implemented in NIST’s fire simulation code. The image at left shows the experimentally-measured velocity field of a fire sprinkler spray. (No longer an active area of research.) See publications here.
Turbulent Boundary Layers
We have contributed to advances in the calibration methods for hot-wire anemometry, the application of hearing aid microphones to measure wall pressure in turbulent boundary layers, the analysis of microphone resolution in wall pressure measurement, and the details of axisymmetric turbulent boundary layers on cylinders in axial flow.(No longer an active area of research.) See publications here.
Physical Acoustics
Acoustic measurements have the potential to provide a fingerprint for the composition of gas mixtures. The speed of sound in a gas mixture is directly related to the molecular weight of the component gases. Molecular relaxation and the classical mechanisms of viscosity and heat conduction cause the absorption of sound in a mixture of gases. We developed the first model for acoustic attenuation in multi-component gases based on quantum mechanics, kinetic theory of gases, and acoustics in order to exploit these characteristics to explore acoustic sensors to measure gas composition. We have developed a prototype gas sensor based on acoustics for NASA and explored acoustic propagation in the atmospheres of several planets. The image at left from the European Space Agency shows the Huygens probe descending to Titan, a moon of Saturn for which we have estimated the acoustic properties. (No longer an active area of research.) See publications here.