TE probe installation

I have been trying to understand just how a TE probe functions.

Is a TE probe plumbed as the only static source for a variometer or is it plumbed together with the static ports that are usually placed on the sides of a glider?

Thank you.

On Thursday, December 4, 2014 2:02:55 PM UTC-5, Jim Lewis wrote:
I have been trying to understand just how a TE probe functions.

Is a TE probe plumbed as the only static source for a variometer or is it plumbed together with the static ports that are usually placed on the sides of a glider?

Thank you.

Probe replaces static and provides a source to the variometer that is of the same magnitude as pitot pressure, but the opposite sign.
UH

http://www.nadler.com/sn10/Brozel_TE...n_20020510.pdf

Here is some help
Nick

On Thursday, December 4, 2014 12:13:40 PM UTC-8, Nick Kennedy wrote:
http://www.nadler.com/sn10/Brozel_TE...n_20020510.pdf

Here is some help
Nick

Thank you Nick, and thank you UH.

I have also read in several references, including Reichmann, that the TE venturi pressure must be -1. I do not understand what this means. Can you explain this without heavy math?

Thank you

On Thursday, December 4, 2014 7:47:08 PM UTC-5, Jim Lewis wrote:
On Thursday, December 4, 2014 12:13:40 PM UTC-8, Nick Kennedy wrote:
http://www.nadler.com/sn10/Brozel_TE...n_20020510.pdf

Here is some help
Nick

Thank you Nick, and thank you UH.

I have also read in several references, including Reichmann, that the TE venturi pressure must be -1. I do not understand what this means. Can you explain this without heavy math?

Thank you

This may help clarify things some (this doc is in early draft and may still have bugs) https://dl.dropboxusercontent.com/u/...xplainedV2.pdf
The -1 is based on what is experimentally measured for the flow around a cylinder.
JP

I am replacing my Cirrus fuselage probe with a new rail mounted probe. From my research it appears ILEC wants it turned up with the head in the same horizontal plane as the horizontal stabilizer. This will be the all moving stabilator on my Cirrus. Do you guys agree with this placement?

Lane
XF

On Friday, December 5, 2014 7:42:13 AM UTC-5, wrote:
I am replacing my Cirrus fuselage probe with a new rail mounted probe. From my research it appears ILEC wants it turned up with the head in the same horizontal plane as the horizontal stabilizer. This will be the all moving stabilator on my Cirrus. Do you guys agree with this placement?

Lane
XF

Sensing quality, assuming fin mounting is generally improved by being as high as possible above the wing root wake and well forward of the pressure field from the tail surfaces. "Well forward", from my experience, is at least 24 inches. I have found no improvement when going more than 36 inches forward and the improvement is fairly small above 24 inches.
UH

Thank you JP. I'll dig into the info today.

Forgive me for this simple-minded question. What pressure (static, dynamic, total) is provided to the variometer by the TE probe? I have read that a TE probe must create a pressure inverse but equal in maginitude to the dynamic pressure at the pitot. This confuses me. I thought the pitot 'receives' total pressure not just dynamic pressure.

I do understand that a variometer is a flow meter that responds to the flow of air between a capacity and the pressure sensed by the static ports. Does the TE probe provide this static pressure (offset by changes in dynamic pressure created by the glider varying airspeeds) or is the TE probe providing dynamic pressure to its side of the variometer?

I am trying to understand the TE process without being able to actually measure the pressures involved.

Thank you.

Without getting into the math (mainly because I don't remember any of
it), the TE probe delivers static pressure reduced by the suction effect
caused by the air flowing around the probe. Remember that the holes in
the TE probe are near the back and, according to Bernoulli (I think it
was), when the velocity increases around the probe the pressure is
reduced and vice versa.

On 12/5/2014 9:26 AM, Jim Lewis wrote:
Thank you JP. I'll dig into the info today.

Forgive me for this simple-minded question. What pressure (static, dynamic, total) is provided to the variometer by the TE probe? I have read that a TE probe must create a pressure inverse but equal in maginitude to the dynamic pressure at the pitot. This confuses me. I thought the pitot 'receives' total pressure not just dynamic pressure.

I do understand that a variometer is a flow meter that responds to the flow of air between a capacity and the pressure sensed by the static ports. Does the TE probe provide this static pressure (offset by changes in dynamic pressure created by the glider varying airspeeds) or is the TE probe providing dynamic pressure to its side of the variometer?

I am trying to understand the TE process without being able to actually measure the pressures involved.

Thank you.


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Dan Marotta

Thank you Dan. That helps a lot.