Principles and examples of drag reduction in civil airliners

Abstract

Civil aviation has grown rapidly over the past hundred years as demand from air travellers has increased. Since the mid to late 20th century, there have been recurring global energy crises due to political and economic upheavals. In this international context, airlines have tended to operate less draggy, more fuel efficient aircraft in order to maximise profits through fuel cost savings . To this end, aircraft manufacturers have historically tried a variety of methods to address the issue of drag reduction.This paper highlights the importance of three drag reduction methods utilized on modern subsonic airliners by introducing their basic principle and evaluating their effectiveness based on previous research and typical experiments. This paper summarizes and analyzes different approaches to reduce drag in civil aviation. It first investigates the principle behind frictional, induced, and profile drag in theoretical aspects. It then discusses in detail the biomimicry microstructure based on shark skin and its uniqueness on aircraft fuselages surface to reduce frictional drag, the split scimitar winglet and its ideal performance to reduce induced drag when compared with other wingtip devices with different cant angles. The newly introduced adaptive lifting surface changes the wings geometric configuration momentarily, and its ability to reduce profile drag at different stages of flight. This paper also comprehensively compares both the benefits and potential compromises of these drag reduction methods.