Hydromagnetic Stability of Spiral Flows

Abstract

In the present paper an attempt has been made to investigate the effects of the axial magnetic field and the axial currents on the stability of spiral flows of a non-dissipative system. A sufficient condition of stability is obtained when all the four components, namely, the swirl velocity, axial velocity, axial magnetic field and axial currents are present. In particular, the case, when the axial velocity is not present, is discussed in detail and it has been shown that the sufficient condition for stability obtained by Howard and Gupta is valid only for oscillatory modes and further the necessary condition for the existence of non-oscillatory neutral modes is obtained.