Longitudinal static stability of a blended wing-body unmanned aircraft with canard as longitudinal control surface / Rizal E. M. Nasir, Wahyu Kunjoro and Wirachman Wisnoe

Blended wing-body (BWB) aircraft, while having good aerodynamic efficiency,
is hampered with issues related to its flight stability and control. To ensure
longitudinal stability, a control canard is incorporated on Baseline-II E-2 BWB
design. Mathematical representations of aerodynamic characteristics and stickfixed
trim flight stability, and analyses on the influence of some parameters to trim
flight of this BWB aircraft with a control canard are highlighted and discussed.
Baseline-II E-2 BWB aircraft is statically stable in longitudinal direction.
However, this is true only for flight within low angles of attack. Mathematical
models of trim flight parameters established here produces plots that have good
agreement with plots of trim flight parameters found directly from wind tunnel
experiments. Large static margin demands large positive canard angle for trim
flight while agility can be achieved by moving the CG closer to aircraft’s neutral
point. The best static margin for Baseline-II E-2 BWB is chosen based on the
best lift-to-drag ratio attainable during trim flight.