On Some Recent Applications of the Coanda Effect to Acoustics

Abstract

Over the last quarter century or so, the Coanda principle has become increasingly used in a wide variety of applications, including industrial, medicine, maritime technology, and aerodynamics. In addition, its effect has been increasingly observed in the natural world. Devices employing this principle usually offer substantial flow deflection, and enhanced turbulence levels and entrainment compared with conventional jet flows. However, these prospective advantages are generally accompanied by other significant disadvantages such as jet flow detachment, a considerable increase in associated noise levels etc. In many cases, the reasons for this are not well understood. Consequently, in many cases, the full potential offered by the Coanda effect is yet to be completely realized. This paper discusses a variety of recent applications of the principle and describes attempts to understand some of the difficulties associated with it, particularly those related to increased noise levels.