PIV Lung Model Test Setup December 14 th, 2012

Components Model Pump Pressure measurement Pressure control

Model – Silicone Block Positives: Will make index matching easier Robust Rapid prototyping material is fairly inexpensive ($10-20 per lb) We have step-by-step guide Negatives: Have not been able to find anyone who can rapid prototype in PVA for the dimensions of the 14 th generation Would need to be outsourced Possibly bubbles in silicone If outlets don’t lie in one plane, we would have to figure out a way to have the outlets extended to exit block Cost: 5 gal of Silicon=$1,719.96

Model – Rapid Prototype Positives: Able to create features with high resolution Could prototype additional features onto model Easier to access all sections of the model Possible to prototype all generations Easier to attach valves/sensors Negatives: Would need additional holding for index matching More delicate Cost: High (Due to intricacy of the part)

Model - Rapid Prototype Block Positives: Robust Could add connectors to the model at the outlets Easy for index matching Easier to rapid prototype that lung model or negative model since it is more structurally sound Negatives: Need a large rapid prototyping machine Cost: Most expensive out of all options

Model - Rapid Prototype w/ Wax Positives: Same positives as Silicon Block model Melts at 75 C, well within Sylguard’s 200 C Easier to rapid prototype because it is a solid negative Negatives: Only possible for Silicone Block Model Need a large rapid prototyping machine Have not found anyone to make a model as large as ours (jewelry) Cost: $75 per 500 mL of Wax

Model – Other thoughts Is it possible to scale model up as long as Reynold’s number is matched? Wouldn’t have to worry about small diameter sizes Is the army sending the model out to their own rapid prototyping company?

Pump – Positive Displacement Current options are gear pumps and flexible impeller pump Positives Can handle viscous liquids Can handle a variety of pressures given a specific flow rate Capable of lower flow rates Capable of bi-rotational operation Negatives Slip possible Issues with PIV particles being pumped correctly Cost Pumps are approximately $500

Pressure Measurement Force Pads –These devices would be an option for use with the silicon cast method A pressure tap would be used and this would be located on surface of casting to measure force applied by fluid Pros flexible, light, cheap (10-20 per unit) Cons may lack degree of accuracy needed, obstruct view through casting Cheapest data acquisition DAQ device is $279 NI USB > only 8 inputs NI USB Pressure Scanner provided by Wellin may be possibility

Pressure Control - Micro-low pressure valves seem to be the best option These can be purchased in multiple forms (2 way, 3 way) and have the capability of going down to an inner diameter of.25 mm Pros Only dollars per unit Can work sensing into device Can adapt to reverse flow Cons May obstruct flow Not precise

Customer Needs 1.Create model of a hollow lung using specified geometry up to the 14th generation. 2.Obtain flow field profiles using particle image velocimetry. 3.Obtain velocity field maps at 10 locations for 5 planes at each location. 4.Validate computational flow model. 5.Accommodate various image locations. 6.Simulate inhalation and exhalation at steady state. 7.Control flow at each airway outlet to mimic the boundary conditions of the computational model. 8.Monitor flow rate and pressure. 9.Accommodate imaging with no distortion. 10.Create Labview program to run experiment. 11.Write a procedure for the experiment. 12.Locate same image positions 13.Can switch between two models

Possible Specifications 1.Model Reynolds number must be within X% of lung Reynolds number 2.Pressure at intake must be equal to atmospheric pressure 3.Must match indexes of refraction within ±X 4.Must have less than X amount of bubbles per X 5.Model can be rotate 6.Model can be translated 7.Camera can be rotated 8.Camera can be translated 9.Must be able to locate the same point within 5mm 10.Models can be switched in under X hours 11.Must support X weight 12.Measure pressure withn X accuracy