A yaw control method for tailless flying wing aircraft under low speed condition

The yaw of a tailless flying wing aircraft (TFWA) is usually controlled with a split drag rudder or spoiler slot deflector. The yaw control mechanism of the split drag rudder is different from that of the traditional rudder in that the former's rudder effect is nonlinear as the deflection varies. The split drag rudder may produce control reversal when the TFWA has large angle of attack, causing directional oscillation and a flight accident. Therefore we use the CFD method to analyze the control characteristics of the split drag rudder of a certain miniature TFWA and propose a method for dynamically controlling the biased deflection of the split drag rudder based on the angle of attack feedback, which is then verified through nonlinear numerical simulations and flight tests. The simulation and test results and their analysis show preliminarily that our method can reduce the nonlinearity and control reversal of the split drag rudder and enhance the yaw control performance of the TFWA under the low speed condition.