Application of Circulation Control manoeuvre effectors for three axis control of a tailless flight vehicle

The application of Circulation Control manoeuvre effectors to a tailless flight vehicle enables the possibility of providing control of moments about three axes without use of conventional flapped control surfaces. This paper develops a low order design methodology for sizing CC effectors based on an extension to existing data sheet methods for estimating pitch and roll control from conventional flight controls. The method relies on input of experimental data for the 2d change in lift and change in pitching moment with blowing coefficient. There is ample data in the extensive CC literature enabling estimation of lift from CC, however there is little data that enables extraction of the pitching moment change due to CC. A case study is presented in which the provision of three axis control moments using CC is evaluated for a tailless 20Kg class gas turbine powered model aircraft. Wind tunnel experiments are used to demonstrate the validity of the aerodynamic design of the vehicle and the ability to produce control moments from CC sufficient to meet basic trim and manoeuvre requirements. The peak values of CC control gains achieved for δCL/δCμ and δCMoδ Cμ are 20 and 12 respectively. The control gain for δC D/δCμ for use as part of a 'thrust' based yaw control scheme from blowing from both upper and lower slots is low (approximately 1), however this is sufficient to trim the case study aircraft at 7 degrees of sideslip at cruise conditions with 10% mass flow bleed from the engine. Copyright © 2009 by Christopher Harley.