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The numerical solution of steady, three-dimensional, inviscid, supersonic flows is applied to the calculation of Magnus forces on spinning cones at angle of attack. The Magnus force is made up of several contributions; the contribution due to the asymmetrical boundary-layer displacement-thickness interaction with the inviscid flow field is considered here. Three-dimensional, laminar boundary-layer solutions for the spinning cone were obtained by methods described in Part I of this paper. The displacement-thickness contribution to the Magnus force is calculated by solving the complete inviscid flow field over body shapes obtained by adding the three-dimensional displacement thickness to the cone radius. The gas dynamic equations are solved by applying MacCormack's second-order shock-capturing finite-difference technique. Special precautions had to be taken in both finite differencing and in applying the surface boundary conditions to maintain enough significant digits in the pressure calculation, since the Magnus force is as small as one part in three hundred of the normal force for some cases considered. The displacement-thickness contribution to the Magnus force, along with three other contributions described in Part I of this paper, are summarized here in Part II. The considerable cancellation effect observed among the four contributions shows that all of the components must be included if accurate predictions of the Magnus force are to be obtained. (Author), See also Part 1, AD-A013 518.

A detailed investigation of the laminar boundary layer flow over a spinning right circular cone at small angle of attack has shown that there are at least four significant forces contributing to the Magnus force on the cone. In order to calculate these forces a novel numerical method has been developed which can calculate these small forces over a wide range of flow parameters. The flow conditions have a large influence on the relative magnitude of the Magnus force components and there can be significant cancelling of the various components. An investigation has also been carried out to show that boundary layer calculations are valid at small angles of attack and that 'boundary region' techniques are not needed until moderate angle of attack. (Author)

The Combined Rocket-Warhead (CROW) is a concept for an artillery round in which the steel chamber of the propulsion unit is surrounded with a high-explosive. This Division was asked to demonstrate that a total impulse of 400 lbfsec could be delivered within the envelop restrictions and with less than a 200 F temperature increase on the external surface of the motor tube. Internal-burning-star and slottedtube grain designs were considered but an analysis of propellant strains at low temperature showed the slotted-tube grain to be superior. A plastisol nitrocellulose composite propellant (RH-P-340) containing 7% inert plasticizers was used for experimental firings. Thermal insulation and case protection were provided by an asbestos-phenolic material. Seventee CROW motors were fired; all ballistic data and pressure-time curves were satisfactory. The temperature at critical points were measured with thermocouples. Temperatures which could be expected in a thin-wall flight-weight motor were estimated. A computer program was used to analyze the effects of wall thickness and external insulation. Results of these analytical studies and experimental tests defined the insulation thickness required to hold the maximum temperature increase of the CROW motor to less than 200 F. (Author)