Integrated System Build & Test with Customer Demo
Table of Contents
March 28th - April 13th, 2017
Team Vision for System Level Demo with CustomerSummarize:
The primary goal of this stage is to complete the system to a functional level where actual and meaningful data can be collected as originally designed. The subsystems should all work together as a unit and all hardware and software should display a level of reliability and usability. Specifically, we intend to be able to produce acceleration data and FFT frequency analyses of poppet valve movement within the valve manifold assembly. Furthermore, there should be characterization of frequencies when comparing poppet valves with different springs or with more or less wear.
During this phase we continued working on our technical paper and poster. We received the correct pressure regulator valve for the backpressure tank. We also updated our bill of materials with the mufflers. The solenoid valve timing was adjusted to have closer results to the actual compressor. More preliminary tests were done to look at the frequency spectrum of a few different valve timing configurations. Once we received the mufflers and attachments, they were installed on our system and they successfully reduced the noise of our rig. O-ring grease was applied to prevent the o-rings from falling out of place during assembly and disassembly. Brackets to hold the pressure regulator were machined and incorporated into our system. A leak was discovered in a quick-release connection and it was fixed. Solutions to the problem of SignalExpress averaging data for the FFT before the equilibrium cycle were explored. Dr. Kolodziej approved setting the program to run twice; the first time including the non-equilibrium data, and the second time starting at equilibrium. Dr. Kolodziej also found our threaded studs in his office so we installed those with lock-tight and they functioned successfully.
Test Results Summary
The last of the testing procedures could not be done until the pressure cycle was nearly finalized and accelerometers were attached to the pressure vessel.
The goal of this test was to ensure that external vibrations would not alter the vibration data associated with the poppet valves. No observable differences could be detected when running tests with people walking by. However, during testing we saw a big spike in the accelerometer reading during the intake of air. Upon further investigation it was concluded that the air rushing into the tank must be hitting the valve manifold side of the pressure vessel causing the spike.
To reduce the spike in the accelerometer readings, one of the mufflers purchased was placed inside of the pressure vessel on the intake orifice.
As seen in the picture, the muffler only has slits on its side which redirects the air away from direct contact into the valve manifold assembly. Accelerometer data was taken before and after to show the effect of the muffler.
As shown above, the muffler reduced the vibrations' spike by nearly 5 times. This will allow easier analysis of the vibrations during which the poppet valves are active because the amplitude of the vibrations during that time are lower than during the initial intake. It's also worth noting that the muffler did not hinder performance in either pressure increase or timing.
Functional Demo Materials
Weekly progress reports between March 28th and April 13th can be found here.