• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.6
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• pp.81-86
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• 2004

Between rolling airframe missile and swirling propulsion jet passing through convergent-divergent nozzle of the rocket motor, occur exchanges of angular momentum which result in the increase of roll speed of the missile. This phenomena in called jet roll damping. In the study jet roll damping was formulated from conservation equation of angular momentum. And the maximum value of the jet roll damping of KPSAM was estimated with assumed swirl velocity distribution at nozzle exit and compared with result of computation of axisymmetric compressible turbulent nozzle flow.

• Journal of Ship and Ocean Technology
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• v.8 no.4
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• pp.1-9
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• 2004

High lifting devices used for control purposes have received much attention in the marine field. Hydrofoils for supporting the hull, roll stabilizer fins for developing the motion damping performance, rudders for maneuverability are the well-known devices. In the present study, the ability of the rudder with flap to produce high lift was analyzed. The boundary layer control, one of the flow control techniques, was adopted. Especially, to build the blown flap, a typical and representative type of a boundary layer control, a flapped rudder was designed and manufactured so that it could eject the water jet from the gap between the main foil and the flap to the flap surface tangentially. And it was tested in the towing tank. Simultaneously, to know the information about the 2-dimensional flow field, a fin model with similar characteristics as the rudder model applicable for the motion control was made and tested in the cavitation tunnel. In addition, local flow measurements were carried out to obtain physical information, for example, a surface pressure measurement and flow visualization around the flap. And CFD simulation was used to obtain information difficult to collect from the experiment about the 2-dimensional flow.