Numerical Analysis of the Flow in an Annular-Conical Passage

The purpose of this paper is to bring new insights into the flow phenomena in an annular-conical passage, which—as previously disclosed experimentally—forms a toroidal-vortex street. The two-dimensional, time dependent Navier-Stokes equations are solved with an explicit finite-difference scheme based on the Marker and Cell method. Solutions are obtained for four different cone apex angles (β = 60, 90, 120, and 180 deg). For each apex angle three cases of different passage spacing are computed. The Reynolds number ranges from Re = 100 ˜ 5000. The stress is put on the initiation and subsequent development of the toroidal-vortex street. Critical Reynolds number for several parameter settings is determined and compared with experimental results.