Some time ago we began to apply finite element computer methods to extrusion problems and jet flow problems. In this paper we survey the progress that has been made by ourselves and others in the solution of these problems using computer methods. We also put forward a mechanism of swelling that became evident from the computer evidence. The object of our research is to understand the losses at inlet and exit, the shape of the extrudate (or the jet) and ultimately the stability of the flow in terms of basic parameters. In the present paper, we will concentrate on the exit problem only; some progress has been made with the inlet problem but it is a simpler problem than the exit one and we expect that when we understand the latter, then the former can be easily attacked. Although we are talking about extrusion here, it is believed that the methods and some of the results have relevance to other flow problems such as melt spinning, film-blowing and wire coating.
KeywordsShear Rate Deborah Number Dimensionless Group Elongational Viscosity Newtonian Case
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- 4.H.B. Phuoc and R.I. Tanner, Thermally-Induced Extrudate Swell, J. Fluid Mech. in press (1980).Google Scholar