Passive flow control application for rotorcraft in transonic conditions

Abstract

Purpose

Helicopter rotor blades are usually aerodynamically limited by the severe conditions present in every revolution: strong shock wave boundary layer interaction on the advancing side and dynamic stall on the retreating side. Therefore, different flow control strategies might be applied to improve the aerodynamic performance.

Design/methodology/approach

The present research is focussed on the application of passive rod vortex generators (RVGs) to control the flow separation induced by strong shock waves on helicopter rotor blades. The formation and development in time of the streamwise vortices are also investigated for a channel flow.

Findings

The proposed RVGs are able to generate streamwise vortices as strong as the well-known air-jet vortex generators. It has been demonstrated a faster vortex formation for the rod type. Therefore, this flow control device is preferred for applications in which a quick vortex formation is required. Besides, RVGs were implemented on helicopters rotor blades improving their aerodynamic performance (ratio thrust/power consumption).

Originality/value

A new type of vortex generator (rod) has been investigated in several configurations (channel flow and rotor blades).

Citation

Tejero Embuena, F., Doerffer, P., Flaszynski, P. and Szulc, O. (2018), "Passive flow control application for rotorcraft in transonic conditions", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 28 No. 5, pp. 1080-1095. https://doi.org/10.1108/HFF-06-2017-0231