Development of Acoustic Based, Multi-tasking Sensing and Actuation Capabilities for Gas Turbines

Abstract

Abstract : This program is developing acoustic techniques for non-intrusive sensing and actuation of gas flows. Controlling and/or monitoring the degree of mixing between constituents of a multi-component media is a key problem in a variety of applications. Monitoring such mixing processes necessarily requires capabilities for quantification of the level of mixedness. However, quantification of molecular mixedness levels, as opposed to macro-scale entrainment, is difficult. Under this program, we have demonstrated the use of acoustic absorption measurements to characterize an average level of molecular mixedness between gases across the wave propagation path. This report presents the results of example calculations and experiments demonstrating the feasibility of this technique and the significant sensitivity of acoustic absorption levels upon gas mixedness; e.g., measurements reported here show acoustic amplitude differences of up to a factor of ten between identical gas mixtures whose only difference is the level of mixedness of their constituent gases.