Radio Controlled Engine Flow Bench

[49-1183904562]

Mike,

Based on your input above your bench is acting like it has a big leak on the test side.

What setup testing Leak etc have you done??

Rick

[Mike Rappold]

Made some progress tonight. Turns out the reference point I was using for "level" on the mamometers was not truely level. This threw off the measurements for the 3" rise on both. I reset and now both manometers read much closer to the digitil hand held manometer.

Still need some guideance on the incline and how its rise relates to the orifice pressure drop design pressure. Thoughts??

Bruce,
I made a test piece plate with a 0.449 diameter. This matches the orifice plate in bench. Will test tomorrow. I do not fully follow your comments in a previous post though. You mention setting the test pressure at 3" and then the incline at 100%. Do you mean to adjust the incline to what ever angle will allow it to read 100% to match the 3" test pressure?


Tom Vaught,
On the commerical benches, you mention that the pickups for the orifice plates are located within a 1/2" of the OD. Does it matter if the pickup points end faces the orifice? Or should it open up to the chamber area? I would think it should not make a difference but thought I would ask befoere i change my pickup point location.


Thanks in advance.
Mike

[bruce]

[Mike Rappold]

I have made progress since last post. A couple of items done:

- I tried a different location for the test pressure pickup on top of the bench. It does not seem to matter for my bench if it is on the top corner or the lower bottom corner. I get the same readings. The flucuations are minor in both spots.

- I added another location for the differential pressure pickup. The new location is about 3/8" off the orifice plate wall and about 2" from the OD of the orifice. This point gives a slightly different reading than the far corners of the bench. Still testing on this one to see which location appears to be better.

- I think I solved my differential pressure vs. incline height question. I beleive the formula I orginally used to calculate the cfm of a 2 stroke engine was incorrect. It made the flow too low. I used another formula that produced a higher cfm required and thus a larger orifice. When I made a larger orifice plate and tried again tonight, the incline was more in line with what was expected - about 3" for 100% of my desired max flow.

Next steps are to tweak the orifice plate size, make up a same size test plate, and begin testing.

Mike