NATURAL LAMINAR-FLOW RESEARCH FOR SUBSONIC TRANSPORT AIRCRAFT IN THE FRG

This paper gives a survey of the work going on in the Federal Republic of Germany in the field of Natural Laminar Flow (NLF). Measuring techniques for the detection of laminar/ turbulent transition and for the measurement of other quantities of interest are first described. Basic experiments, which are designed to clarify the nature of different types of instabilities in laminar flow, are explained next. A survey is then given of theoretical and semi-empirical methods for transition prediction, followed by flight tests and qualification of wind tunnels. The paper concludes with an example of the design of a laminar engine nacelle.