Simulating and Characterizing Water Flows Inside Hydroentangling Orifices

Abstract

The hydroentangling technique uses cone-capillary orifice nozzles to direct high-energy water jets against loose fiber webs. This study simulates the effects of orifice configuration on the water-jet properties. An axisymmetric steady-state model is considered for this two-phase system. The turbulent water jet is simulated using a realizable k - ε model, and the behaviors of cone-up and cone-down geometries are investigated. The simulation reveals that the water jet produced by a cone-up orifice keeps contact with the walls all the way through the orifice and may undergo cavitation to reduce the water-jet intact length and damage to the orifice surface. In contrast, the cone-down geometry can form a constricted water jet that is enveloped by an air gap, which separates the water from the orifice surface and therefore prevents cavitation. The results are in excellent agreement with previous experimental studies.