Concentration measurements in fluid media

Quantitative flow field measurements are made available through a variety of intrusive and non-intrusive probe and particle tracking techniques. Flow visualization is another tool used to analyze fluid motions but data is limited to qualitative analysis.; Efforts to extract vector field information from scalar field data have shown promise but these methods require the scalar field to exhibit non-zero gradients and typically solution of the conservation equation requires velocity gradients to be calculated. The ability to write additional conservation equations for a second and third conserved scalar produces a properly determined system to solve for three velocity components.; Concentration is a scalar quantity that can be determined using the Beer-Lambert law for light transmission. Single component concentration measurements have been used in conjunction with flow visualization to generate a fully resolved four dimensional scalar field. However, the Beer-Lambert law is not applicable in situations where multiple compounds are present in mixture because of overlapping absorption spectra among flow tracers. This research provides a foundation for measurement of multi-component concentration scalar field in a tertiary mixture. This may provide a means for vector field calculation avoiding the need for velocity gradient calculations.; Fluorescent emission of fluorescein and rhodamine B dye is combined with colorimetry to quantify the primary color light response of a mixture and ultimately individual component concentrations. A third primary color response is elicited by inclusion of milk into mixture test samples. White milk particles scatter the blue wavelengths present in the incident argon ion laser light.; A CCD camera and digital imaging is used to correlate red, green and blue light responses of dyes and milk to concentration. This data initiates an extensive calibration of the dyes when taken in mixture.; Results show concentrations of a three component mixture are attainable but accuracy is limited to the incident light plane. Concentration measurements at points further along the light path requires an integration to track changes in available light. Due to deviations in the concentration measurement, the integration accuracy quickly deteriorates.; To illustrate the application of a multiple component scalar field, a numerical simulation and experimental results are provided.