FLAT SPIN OF AXISYMMETRICAL BODIES

Experimental results are analyzed to develop an understanding of the n ow physics causing fiat spin of axisymmetric bodies, which is a key to the development of the capability for the prediction of the nat spin of advanced aircraft. The flow phenomenon sustaining the flat spin mot ion is the now separation asymmetry due to the moving wall effect at l ocally critical flow conditions on the body, which is made possible by the presence of three-dimensional now effects. Body roughness and mic roasymmetry play important roles in extending the range of ambient now conditions at which nat spin can develop.