Tom584
Mechanical
- Feb 9, 2000
- 12
I'm attemping to model the air pressure distribution around a spherical telescope dome due to wind.<br>
<br>
Air flow through the dome improves "seeing". By modeling the air pressure distribution at given wind speeds, we may be able to optomize the dome to improve air flow and seeing.<br>
<br>
I have used the measured air pressure distribution about a smooth sphere as presented in most fluids books; however, ASHRAE Fundamentals and the load calculation manual use a different Pressure coefficient distribution in that once separation occurs Cp remains negative. The ASHRAE methods are for calculation of infiltration on rectangular or square structures.<br>
<br>
Does anyone have any experiences to share related to the above discussion? The big question is, does the Cp ever really go positive after separation occurs? Is there any papers or studies out there about such a problem? What is the magnitude of a negative Cp at 180° to the wind? <br>
<br>
I do have the option of collecting data using our dome, but the time required to collect such data is not small and presently we do have the equipment.<br>
<br>
Thanks to all who respond. <br>
<br>
<p>Tom Worthington<br><a href=mailto
worthi@astro.as.utexas.edu>pworthi@astro.as.utexas.edu</a><br><a href= > </a><br>
<br>
Air flow through the dome improves "seeing". By modeling the air pressure distribution at given wind speeds, we may be able to optomize the dome to improve air flow and seeing.<br>
<br>
I have used the measured air pressure distribution about a smooth sphere as presented in most fluids books; however, ASHRAE Fundamentals and the load calculation manual use a different Pressure coefficient distribution in that once separation occurs Cp remains negative. The ASHRAE methods are for calculation of infiltration on rectangular or square structures.<br>
<br>
Does anyone have any experiences to share related to the above discussion? The big question is, does the Cp ever really go positive after separation occurs? Is there any papers or studies out there about such a problem? What is the magnitude of a negative Cp at 180° to the wind? <br>
<br>
I do have the option of collecting data using our dome, but the time required to collect such data is not small and presently we do have the equipment.<br>
<br>
Thanks to all who respond. <br>
<br>
<p>Tom Worthington<br><a href=mailto
worthi@astro.as.utexas.edu>pworthi@astro.as.utexas.edu</a><br><a href= > </a><br>