A Compact, Self -Contained System for Boundary Layer Measurements in Flight

A small, lightweight, self -contained research instrument capable of providing direct measurements of the flow near a surface in flight has been developed and tested. The instrument consists of a motorized stage to which a measurement probe is attached, circuitry for timing a nd powering the stage motion, a data logger with sensors and memory, and a battery with power conditioni ng circuitry. The entire instrument is contained within a fairing, weighs well under one pound, and can be affixed directly to a n aircraft surface with structura l adhesive tape. No connection to the aircraft systems or mechanical penetration of the surfac e is required . After a flight, dat a is downloaded to a laptop computer for display and analysis. The system has been successfully tested , both in a wind tunnel , and during three flights on an aircraft wing . It is now available for application to low -spe ed flight research where detailed, local boundary layer measurements are needed.