ESDU 89014 D-2004 Normal force@ pitching moment and side force of forebody-cylinder combinations for angles of attack up to 90 degrees and Mach numbers up to 5.
Item No. 89014 provides a simple empirical means of estimating the normal force and pitching moment of axisymmetric forebody-cylinder combinations for angles of attack up to 90 degrees and Mach numbers up to 5. Although derived using wind-tunnel test data for cylinders with tangent-ogive and cone forebodies (with and without blunting) and secant-ogive and ellipsoid forebodies@ the method is expected to give reasonable estimates for any axisymmetric forebody-cylinder combination with a smooth forebody shape. The method requires as inputs the normal-force-curve and pitching moment-curve slopes at zero angle of attack@ which may be taken either from test data or calculated using Item No. 89008@ and simple geometrical parameters which may be obtained from Item No. 77028. The use of the method is illustrated by a worked example. The effects of boat-tailed may be estimating using Item No. 87033. The calculation procedure is programmed in ESDUpac A9034@ see Item No. 90034. At high angles of attack at subsonic and transonic Mach numbers@ asymmetric vortex flow may occur on the leeward side of the body. This phenomenon@ which is known to depend on such minor factors as small imperfections at the nose@ has the effect of producing an out-of-plane force distribution that can result in large side forces and yawing moments. The Item considers this subject by providing a description of asymmetric vortex flow and the resulting forces@ including effects of Reynolds number and forebody blunting. A discussion of Mach number effects is also given@ together with an envelope of maximum side force.
ESDU 89014 D-2004 history
2004ESDU 89014 D-2004 Normal force@ pitching moment and side force of forebody-cylinder combinations for angles of attack up to 90 degrees and Mach numbers up to 5.