looking at the results related to the real catheter, the flow velocity in this area was almost zero (see Figure 3.25 ). This is the zone were the biofilm start to develop and consequently block the catheter. Flow field parameters changes in this particular location could influence the biofilm growth. However, form Figure 3.27 related to streamlines applied to the experimental fluid domain, it is possible to see a recirculation zone just above the inlet point level so this area was considered during this stage. Figure Catheter fixed DESIGN F2 used for the simulations – FIXED DESIGN F3 The third geometry proposed was aimed at analysing the effect of the areas above the points where the urine enters the catheter and the velocity magnitude are very small. The tip of the catheter was removed and there was no more space available for the flow above the inlets. This zone was considered with a wall condition. The hypothesis behind this choice was that the cut would not make a big difference on the flow behaviour, but it could substantially reduce the available space for biofilm encrustation and development. The recirculation zone was considered small enough and negligible for this first case of study. The other tip details, such as either the eyelet shape or their position, were not modified. In Figure 4.24 the FIXED DESIGN F3 is shown. Figure - Catheter FIXED DESIGN F3 utilised for the simulations. The catheter tip was cut up to the inlet level to see how this change would affect the flow behaviour FIXED DESIGN F4 In the fourth design, the area above the inlet sections, which was the main focus of FIXED DESIGN F2 and F3 was left as the original geometry. As shown in Chapter 2 the sections located in this area showed a really small flow-field
looking at the results related to the real catheter, the flow velocity in this area was almost zero (see Figure 3.25 ). This is the zone were the biofilm start to develop and consequently block the catheter. Flow field parameters changes in this particular location could influence the biofilm growth. However, form Figure 3.27 related to streamlines applied to the experimental fluid domain, it is possible to see a recirculation zone just above the inlet point level so this area was considered during this stage. Figure – Catheter fixed DESIGN F2 used for the simulations FIXED DESIGN F3 The third geometry proposed was aimed at analysing the effect of the areas above the points where the urine enters the catheter and the velocity magnitude are very small. The tip of the catheter was removed and there was no more space available for the flow above the inlets. This zone was considered with a wall condition. The hypothesis behind this choice was that the cut would not make a big difference on the flow behaviour, but it could substantially reduce the available space for biofilm encrustation and development. The recirculation zone was considered small enough and negligible for this first case of study. The other tip details, such as either the eyelet shape or their position, were not modified. In Figure 4.24 the FIXED DESIGN F3 is shown. Figure - Catheter FIXED DESIGN F3 utilised for the simulations. The catheter tip was cut up to the inlet level to see how this change would affect the flow behaviour FIXED DESIGN F4 In the fourth design, the area above the inlet sections, which was the main focus of FIXED DESIGN F2 and F3 was left as the original geometry. As shown in Chapter 2 the sections located in this area showed a really small flow-field
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