INSTABILITY OF THE NON-ISOTHERMAL FLOW BETWEEN A ROTATING AND A STATIONARY DISKS

Abstract

Both theoretical linear stability analysis and the direct numerical simulation are performed to study the transition flow between rotating discs. This paper reports about the three-dimensional spiral and annular patterns computed with a high-order (spectral) numerical method in the B¨odewadt layer of a cylindrical rotor/stator cavity. The characteristic parameters of these boundary layer instabilities are compared with the theoretical results and interpreted in terms of type I and type II generic instabilities. The absolute instability regions are theoretically identified and the critical Reynolds numbers of the convective/absolute transition in both layers are given. The absolute or convective nature of the flows is determined by examining the branch-points singularities of the dispersion relation.

Keywords

• instability and transition in rotating flows
• convective and absolute instability