# Measure dynamci pressure

 Register Blogs Members List Search Today's Posts Mark Forums Read

 April 16, 2007, 01:51 Measure dynamci pressure #1 eric Guest   Posts: n/a Dear Friends, Is it possible to know the direction and the magnitude of the airflow by a Pitot tube. How to know the Direction?? Thank you in advance. Best Regards Eric

 April 16, 2007, 10:14 Re: Measure dynamci pressure #2 ag Guest   Posts: n/a Rotate the tube until you measure the largest total pressure?

 April 16, 2007, 10:17 Re: Measure dynamci pressure #3 Eric Guest   Posts: n/a Thank you for your response. Could you tell me which book or paper I can find that? Mang thanks.

 April 16, 2007, 12:11 Re: Measure dynamci pressure #4 Mani Guest   Posts: n/a It is quite difficult to obtain an accurate measure for the direction of flow with a single pitot probe. The pitot probe is quite insensitive towards angle (which is actually a desired property, as you typically want to get an accurate total pressure measurement without knowing the exact flow angle). A single proble will give you an angle with no less than plus/minus 5 degrees error, typically. This may be good enough, depending on your application. If you need higher accuracy, any book on flow measurements will help you to find suitable devices and techniques to measure angles. For example, a five-hole probe makes use of total and static pressures measured on a typically spherical head to determine flow angles.

 April 16, 2007, 21:09 Re: Measure dynamci pressure #5 Eric Guest   Posts: n/a Many Thanksă€‚

 May 3, 2007, 08:38 Re: Measure dynamci pressure #6 eric Guest   Posts: n/a Dear Mr.Mani, Thank you for your reply in detail. As in my case, the total pressure and the angle of the fluid had been measured by other people with one hole Pitot tube. The angle of the dynamic pressure is decided by rotating the Pitot tube, is it right? And what is the relation between that angle and the velocity(x,y,z dorections) gotten by CFD? Thank you in advance. I am badly needed it for my paper. Thank you very much. Eric