pitot tube questions

user-9274568 · Post by **user-9274568** » Wed Jun 15, 2005 4:13 pm

When probing a port. As an example, do you lay your pitot on the roof or floor or do you leave it off some? Or do you basically find the air path and record that number? Thanks Guys

Chad

shawn · Post by **shawn** » Wed Jun 15, 2005 9:01 pm

I know that i'll take and divide the port up into "quadrants".Depending on how large the port is, larger being more sections,i'll start just inside the port opening at the top left of the roof.The pitot will be just off of the roof the port to get it out of any boundry layer disturbances that would be there.From there i move my way across the port to the top right.The ammount of readingss I may take will again depend on port size.I'll then move down the left side port wall, again just past the opening, and start moving from left to right again. If i was taking readings from 3 points across and 3 points down, when i started my second set of readings i would be half way down the port wall, horizontally.The next point would be "hovering" in the middle of the port, and the third up against the right side port wall.I don't know if i've explained that very well, but hope that's what your looking for?
shawn

Post by **ou812** » Wed Jun 15, 2005 11:17 pm

I check the floor all the way from the port opening to the short turn apex. I leave the tube upright, to try and not disturb the air while probing. I also check at and after the push rod pinch for air speed keeping the tube upright to check bottom to half way up and then turn it upside down to get the middle to top. then I set the top of the pitot tube against the roof, and work from port opening to guide boss measuring the middle of the port airspeed. I will also check the corners of the st apex and then down from the apex to find where the fastest part of the port is.
Brian

shawn · Post by **shawn** » Thu Jun 16, 2005 2:30 am

I guess I could have finished my post. I do the same thing as Brian. After checking the port opening I'll do the same thing woking my way towards the valve. Usually checking the opening,the pinch,between the pinch and the short turn,and at the short turn apex.Sorry for leaving that part out. Typing this out on my Blackberry I get in too much of a rush.

Shawn