Identifying Disturbance Sources in Shear Flows Using the Degenerate Unmixing Estimation Technique

摘要

Disturbance source identifcation is important in laminar to turbulentrnrow transition and in active row control applications. A novel method isrnpresented for blind disturbance source separation (BSS) from a limitedrnnumber of measured mixtures of sources, in which the mixing proces-rnses are unknown beforehand. The method is based on an adaptationrnof the Degenerate Unmixing Estimation Technique (DUET) for use inrnshear row applications. DUET can discover any number of sources byrnusing only two sensors, which renders it very eu000bective relative to otherrnBSS techniques. A theoretical framework is developed for separating Nsrndisturbance sources generated in a boundary layer using two sensors byrnusing DUET. Linear stability theory for Blasius boundary is employedrnto model the downstream propagation of small disturbances. Numeri-rncal and experimental proofs of concept are provided, that demonstraternthe power of the new method. Employing two sensors to separate up tornthree disturbances generated from Ns sources, the numerical simulationsrninclude 2D Tollman-Schlichting waves and 2D wave-packet disturbances.rnWind tunnel experiments involving boundary layer row over a rat platernwere carried out, in which two hot-wire anemometers were used to se-rnparate disturbances generated by two disturbance generators: a singlerndielectric barrier discharge (SDBD) plasma actuator and a loudspeaker.