AN ASYMPTOTIC INVESTIGATION OF THE NON-STATIONARY MODES OF INSTABILITY ON A ROTATING-DISK IN THE PRESENCE OF A LARGE MAGNETIC FIELD STRENGTH

摘要

Asymptotic solutions for stationary and non-stationary modes for the upper and lower branch disturbances assuming large scale magnetic fields are investigated. A triple deck structure which governs the lower branch modes for a large scale magnetic field is displayed. The wavenumbers and waveangle calculated from the eigenrelations a≈2.62m~(5/4)r~(-1/2), β≈0.78 m~(1/4)r~(1/2), φ = 0.298m~-~1r, to be consistent with the numerical results for large scale magnetic fields.