Flow in an Annular-Conical Passage.

Abstract

An experimental study has been conducted on the flow behavior in an annular-conical passage. Experiments are carried out for three different cone apex angles (β=60°, 90°, 120°). For each apex angle two cases of different passage spacing are studied. The emphasis is placed on the transition from laminar to self-sustained oscillating flow regime in which the critical Reynolds number is investigated in relation to the apex angle and passage spacing. It is found that the critical Reynolds number depends on both the cone apex angle and passage spacing. For the self-sustained oscillating regime the Strouhal number is evaluated also with respect to both the passage spacing and cone apex angle and the dependence of the Strouhal number on the Reynolds number is determined.