SGER: Feasibility Study of a Molecular Based Approach for the Plannar Mapping of the Pressure Field within Flows

Michigan State University, East Lansing MI

Investigators

Abstract

ABSTRACT PROPOSAL NO.: CTS-0649744 PRINCIPAL INVESTIGATORS: M. KOOCHESFAHANI INSTITUTION: MICHIGAN STATE UNIVERSITY This is an exploratory research project aimed at development of a molecular-based approach for planar, whole-field mapping of the pressure field in gas flows. The method is built on concepts behind Molecular Tagging Velocimetry (MTV) using phosphorescent molecular tracers. Instead of avoiding the detrimental quenching effects of oxygen in MTV applications, we take advantage of it in order to determine the oxygen concentration and, therefore, the local pressure in oxygen-containing gas flows. The working principle of the proposed pressure measurement approach, referred to as Molecular Tagging Manometry (MTM), is quite similar to that of pressure sensitive paints (PSP), i.e. the quenching of phosphorescence by oxygen. In PSP, the phosphorescent molecule (i.e. lumophore) is embedded in a coating that is painted on the surface of interest. In MTM, however, the lumophore is premixed in the fluid itself and its quenching by oxygen leads to a procedure to map the pressure field in the flow. The basic theoretical framework for the method is developed. However, the essential experimental complications and limitations of the approach are completely unknown and difficult to predict. As such, the exploratory work is somewhat risky. Should this project meet with success, its potential broader impact on the field can be significant. It will offer a methodology for capturing the whole-field pressure distribution within the body of a flow, a capability that has so far remained elusive.