Several very practical obstacles presently keeping both riblets and hybrid laminar flow control (HLFC) form inservice applications have been reviewed. For riblets, proving economic viability is a major challenge that will requires an order of magnitude reduction in the time to apply them relative to the best application times demonstrated to date. And, this reduced application time must he achievable by non-specialized workers. In addition, the airlines must be convinced that riblets will retain their full performance benefits for five years with minimal additional attention required. Then, to make the total riblet drag reduction worth pursuing, it will be necessary that riblets can be used on wings and tails without adversely impacting flight characteristics which can effect operating economics. Practical challenges needing to be overcome for HLFC include the definition/development of a practical/effective wing ice protection system compatible with HLFC that does not adversley impact performance characteristics, and devising a means to overcome the performance deficiencies and risk incurred by the requirement to use a Krueger-type leading-edge device (in lieu of a slat). Further, it will be necessary to demonstrate that HLFC can be effectively used in the wing root area and in areas on the wing influenced by the installation of VHBPR engines, plus wind-tunnel-testing techniques must be conclusively demonstrated to the airlines. The final challenge for HLFC is to overcome all of the foregoing obstacles without having to resort to a full-up prototype program prior to launching a production aircraft program.
Some practical aspects of viscous drag reduction concepts
Einige anwendbare Gesichtspunkte von plastischen Widerstandsverminderungs-Konzepten
SAE Technical Papers ; 1-12
1991
12 Seiten, 8 Bilder, 18 Quellen
Conference paper
English
SOME PRACTICAL ASPECTS OF VISCOUS DRAG REDUCTION CONCEPTS
SAE Technical Papers | 1991
|Viscous Drag Reduction in Aeronautics
British Library Online Contents | 1994
|