Negative x axis result
 

Wonder if anyone has any thoughts on these results (pic below). Bit of background first. This is for a rather nippy fixed wing I've been developing. MTOW about 25kg, 1.3m nose to tail and a wingspan (delta) of 1.1m. Has a Kingtech 320 turbine. As CFD is not my area of expertise, these results just seem "wrong". In essence, I've had CFD performed and my interpretation is the results indicate massively reduced drag at increased angle of attack - even going negative (i.e. the x axis goes from around a sensible 50N at 0 degrees AoA to a negative value). On discussion there was some suggestions raised about vortex creation and such, but something just seems not to add up. Many thanks for any suggestions! Oh, and these runs are at 100m/s...