ABSTRACT
This chapter provides the details of the flying-strut traverser, smoke generators, illumination and viewing of smoke, and application examples. Smoke is a widely recognized form of flow visualization that can produce very attractive results with wide appeal from many perspectives. The flying-strut traverser employs long slender strut elements with airfoil cross-sectional shapes that are continuously controlled in angle of attack to keep them aligned with the local flow direction. Each flying-strut element utilizes a mechanical trimming system that produces a coupling between the flapping and feathering motion of the strut elements. It is possible to develop a wind tunnel smoke generator using combustion, but several alternative methods have been developed which are much more convenient. The most common smoke generator for this application uses a vaporization—condensation reaction. The smoke generator was enclosed in a flying strut that extended into the test section through a small opening in the ceiling.
