Virtual flight test techniques to predict a blended-wing-body aircraft in-flight departure characteristics

As one of the promising configurations of the next generation of commercial aircraft,research on departure characteristics of the Blended-Wing-Body(BWB)is of great signification to safe flight limits.A three-degree-of-freedom(3-DOF)virtual flight test in a wind tunnel has been implemented for a candidate configuration to predict the departure characteristics.The support mechanism,the test model and the control law of the virtual flight test are introduced.In order to show the relationship between virtual flight test and actual flight test,the similarity criterion is also given.In open loop,the model has mild oscillations in the longitudinal and lateral directions,which are stable in closed-loop.The effect of flight control has been verified in virtual flight and actual subscale flight test.The analysis of system identification results indicate that the model has a good response to the excitation signal,and the response is in reasonable agreement with the flight test.Finally,the virtual flight departure test results are compared with the flight test.It shows that there is a good correspondence between the angle of attack and the elevator deflection at departure.This gives promising evidence of the practicability of virtual flight testing to predict departure of a BWB.