Catheter fluidics suite
Pressure / flow / Reynolds for a catheter lumen. Hagen-Poiseuille (laminar) and Darcy-Weisbach (turbulent), with regime detection. Solve from pressure or from flow rate, on circular or oval lumens.
Laminar (Re < 2300): Hagen-Poiseuille for circular lumens; analytic extension for oval lumens.
Turbulent (Re > 4000): Darcy-Weisbach with Blasius friction factor.
Reynolds: Re = ρ·v·Dh / η, with Dh = 4·A/P hydraulic diameter.
Hagen-Poiseuille — laminar pressure drop in cylindrical channels (1838-1840).
Darcy-Weisbach — pressure drop in pipe flow with Blasius friction factor.
Reynolds transition criteria — laminar < 2300, turbulent > 4000.
Fluid properties at 37 °C (saline, water, iodinated contrasts).
Newtonian assumption. Real blood and high-viscosity contrasts are non-Newtonian — viscosity drops with shear rate. Treat results as upper bounds for contrast media at low flow.
Rigid walls assumption. Compliant catheters expand under pressure, increasing effective Dh — actual flow can be slightly higher than predicted.
The hydraulic-diameter approach for oval/free shapes is approximate (10–20 %) outside circular geometries — validate experimentally for safety-critical lumens.
Protobrix · Lumen sizing, balloon profile, infusion-rate trade-offs. From concept to small-series.
Need help on lumen sizing?
Hydraulic predictions are first-order. Real catheter fluidics depend on non-Newtonian effects (blood, contrast), wall compliance and end effects — validate against bench measurements.
Lumen sizing, infusion-rate trade-offs, balloon inflation profile? Our catheter engineers can help — from concept to small-series.
Request received.
We'll get back to you within 1 business day.
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Catheter fluidics suite
Pressure / flow / Reynolds for a catheter lumen. Hagen-Poiseuille (laminar) and Darcy-Weisbach (turbulent), with regime detection. Solve from pressure or from flow rate, on circular or oval lumens.
Laminar (Re < 2300): Hagen-Poiseuille for circular lumens; analytic extension for oval lumens.
Turbulent (Re > 4000): Darcy-Weisbach with Blasius friction factor.
Reynolds: Re = ρ·v·Dh / η, with Dh = 4·A/P hydraulic diameter.
Hagen-Poiseuille — laminar pressure drop in cylindrical channels (1838-1840).
Darcy-Weisbach — pressure drop in pipe flow with Blasius friction factor.
Reynolds transition criteria — laminar < 2300, turbulent > 4000.
Fluid properties at 37 °C (saline, water, iodinated contrasts).
Newtonian assumption. Real blood and high-viscosity contrasts are non-Newtonian — viscosity drops with shear rate. Treat results as upper bounds for contrast media at low flow.
Rigid walls assumption. Compliant catheters expand under pressure, increasing effective Dh — actual flow can be slightly higher than predicted.
The hydraulic-diameter approach for oval/free shapes is approximate (10–20 %) outside circular geometries — validate experimentally for safety-critical lumens.
Protobrix · Lumen sizing, balloon profile, infusion-rate trade-offs. From concept to small-series.
Need help on lumen sizing?
Hydraulic predictions are first-order. Real catheter fluidics depend on non-Newtonian effects (blood, contrast), wall compliance and end effects — validate against bench measurements.
Lumen sizing, infusion-rate trade-offs, balloon inflation profile? Our catheter engineers can help — from concept to small-series.
Request received.
We'll get back to you within 1 business day.
Leaving without a result? In one line — what were you looking for?
Thanks for using the tool. Two quick things that help us:
Suggested text copied — paste it into your LinkedIn post.
Thank you.
Noted — this helps us improve.
