Fluid flow and species transport around a scaffold Centro Interdipartimentale di Fluidodinamica e Idraulica & Department of Energy & Technology, University of Udine, Italy F. Beux, M. Campolo, A. Soldati Centro Interdipartimentale di Fluidodinamica e Idraulica University of Udine - Italy Prepared for VIVABIOCELL

Problem The flow field controls: Conditions for cell adhesion and growth Transport of nutrients 34 mm 6 mm Φ= 4 mm Q=4 cm 3 /min Re=21 Water

Objects A. Evaluate the flow conditions inside the bioreactor to: Establish the actual throughput Verify the flow homogeneity (possibility to feed nutrients/remove catabolites, presence of dead regions) Quantify the shear distribution (relevant for cellular growth) B. Identify possible design modification to improve performances

Computational domain ¼ overall domain About FV > 10 FV

1. Results: pressure drop & power Maximum pressure drop in small connecting pipes (increase diameter if P is too high) ∆p= 160 Pa P=10 -5 W

2. Results: flow field homogeneity (in-out)

2. Results: flow field homogeneity (corner)

2. Results: velocity in volume Maximum velocity in small connecting pipes Minimum velocity in the flow diffuser

3. Results: shear scaffold wall p= 8e-5÷0.03 Pa

3. Results: shear stress statistics

Average shear stress variation along scaffold

Concluding remarks 1.In-Out pressure drop depends on number and diameter of connecting pipes 2.Flow homogeneity con be improved by changing the angular position of inlet/outlet connecting pipes (45°) 3.Possibility to evaluate transport (and reaction) of species