Numerical and experimental study of the flow converging at or emerging from the apex of a conical surface for near zero Re values.

The results of a numerical and experimental study of the steady state flow in the vicinity of a conical nozzle in the injection and withdrawal processes for near zero Re values are presented. The flow was numerically solved for nozzles with aperture angles of 90, 105, 120 and 135 degrees at Re values of 0.01, 0.1, 1.0 and 10.0. Numerical solutions were obtained by applying a sharp interface immersed boundary method to a streamfunction-vorticity formulation in cylindrical coordinates discretized in finite differences. The velocity distribution was experimentally measured using the PIV technique for aperture angles of 90 and 135 degrees and for Re 0.01. Results are presented in the form of velocity fields, streamline plots, contour levels of the streamfunction and plots of the streamline separating the main and surrounding flows. A comparison of the results of both studies, when the geometry and flow regime are equivalent, is presented.