Pressure Control Subsystem

Comprised of…

-t hose splitter

-dual flow needle valve

-amplified voltage pressure transducer

-powered breadboard

Needle Valve

Chosen due to…

-high resolution therefor minor adjustments to flow can be made (5 turns)

-dual flow capability (allows inhale and exhale simulation)

-low profile for organization

-low cost (20$)

T Hose Splitter

Important to…

-separate static pressure from dynamic flow

-allow pressure readings to be taken parallel to flow increasing accuracy

-organize flow path from model to valve system

Amplified Pressure SensorWas chosen based on…

-accuracy (can measure static pressures +/- 1% with proper calibration)

-cost (65$ per sensor)

-compact design (no extensive cables or adaptation, plug into breadboard)

-easy to calibrate and characterize to increase accuracy

Breadboard ImplementationReasoning…

-keeps voltage sensors organized and setup compact

-allows user to adjust voltage getting applied to sensors easily

-flow from pressure control to daq device will be smooth

Pressure Control PathFluid will leave outlet

With steady state conditions fluid will separate due to splitter and apply static pressure on sensor

Flow will be adjusted with needle valve based on logger pro readout compared to desired conditionsBack to

pump

Calibration Technique

Fluke 718 series

-can use to apply very accurate known pressure

-output voltage can then be read and adjusted to create new curves accurately matching sensor performance

-acquired device through department