Table of Contents
Final System Pugh ChartThe two designs that were proposed in the preliminary detailed design review are compared in the pugh chart below. Based on the results of this pugh chart, the four solenoid design was chosen.
FeasibilityThe calculations below show the various mechanical and electrical properties that need to be analyzed to determine if solenoid technology is a possible solution for active actuation. The first property that was determined was the orifice area of the outlet valve. This will influence the amount of actuation the solenoid valve will need to achieve in order to create an opening large enough to empty the vessel at the determined frequency. From these first two calculations, it has been concluded that the solenoid can actuate the distance necessary to achieve the outlet orifice area.
The next two calculations were force calculation. When the solenoid valves are closed, there is a total pressure that will be experienced at the top surface area of the poppets. The total force of pressure and the total electric force of each solenoid were compared in order to determine if the solenoid can produce sufficient amount of force to hold the poppets shut. From these calculations, it has been concluded that a single poppet can remain shut against the force of pressure. There will be four poppets in total to emulate similar passive valve systems.
The solenoid will be limited by a mechanical factor, that is the space between the solenoid housing and the poppet slot of the bottom valve assembly. Calculations were made of various gauge wires to obtain the ideal amount of windings, thickness, and current draw. There is also an electrical constraint which is power. While power consumption is not a problem, heat generation will be. The amount of windings will determine the total electrical resistance of an individual solenoid which will affect the total current draw and power with a constant voltage. It was concluded that 2000 windings for each solenoid will produce ~5 W power. With four solenoids total, the maximum calculated current draw will be ~1 A. The dots that represent 2000 windings are marked by a green pentagon on the graphs. 32 gauge wire was chosen as ideal for our application since it retains a thread-like flexibility, and has a lower resistance than higher gauge wires.
The calculation below shows how an O-Ring with the selected dimensions will be able to create a seal. Because the recommended compression for an O-Ring is between 30% and 40%, the calculations show that with the given parameters, the O-Ring falls within the recommended amount of compression, and then shows what the remaining dimensions should be by calculating them.
Drawings & Schematics
Bill of Material (BOM)
Risk Assesment (Blue denotes new risks). Potential risks added this phase include potential magnetic interference between solenoids and sensitivity in simulation results