Alternative Laminar Flow Techniques

摘要

This paper describes some alternative ways to achieve areas of low-drag laminar flow. These include restoring laminar flow on swept leading edges with simple boundary layer scraper devices, exploiting pressure differences along and across aircraft surfaces, attaching an external porous laminar skin to avoid piercing load-bearing structure and avoiding the need for a powered suction system by the use of suction-hoods. Test results and example calculations are shown and it is suggested that these techniques may be suitable for new-build aircraft or for retro-fitting to many of the existing 20,000 airliners.