M.Sc Thesis

M.Sc StudentDetinis Igor
SubjectSide Forces on a Spinning Cone due to Momentum Addition
DepartmentDepartment of Aerospace Engineering
Supervisor RESEARCH PROFESSOR E Daniel Weihs
Full Thesis text - in Hebrew Full thesis text - Hebrew Version


Injection of jets is a common method for creating side forces by means of momentum addition on bodies moving with supersonic speed. 

The current research presents an alternative method for creating side forces by ejection of solid spherical pellets instead of lateral jets from finite, circular, rotating and non rotating cones, moving at supersonic speed at zero angle of attack.

The research focused on the evaluation of forces acting on the cone as a result of the asymmetrical pressure field created on the cone surface resulting from shock waves around the sphere, and it's interaction with the cone surface. This pressure field causes a significant increase of side forces, above those due to pure sphere ejection mechanical reaction.

A simplified physical model for the problem of the pressure signature on the cone surface due to shock wave around the sphere interaction with the cone surface was defined.

The solution for the simplified model is based on Taylor-Maccoll equation for the flow field around the cone, equation of motions for the spherical pellet with drag coefficient equal to that of sphere in the non uniform flow field formed around the cone and the interactions effects of the shock wave around the sphere and the cone surface.

Based on the solution the sphere trajectory, components of the pressure force acting on the cone due to the pressure signature on the cone surface induced by the shock wave formed around the sphere and the impulse components obtained by the time integration of that pressure force components calculated. In addition we compared between the case of spherical pellet ejection and jet injection.  

The results show that the spherical pellet ejection can be an attractive alternative to jet injection, for rotating cones.