How to filter out the noise?

hi,

I am using Vetrino II to collect the velocity profile behind a rotating propeller.

I try to use the method proposed by Goring and Nikora (2002. JHE, ASCE) to filter out the noise.

The mean velocity profile looks good, however, i am not sure the turbulence intensity is ok or not.

Please check the attachment, which contains the measuremnt result.

Please have a look when you are free.

Dino

Hi Dino,

  I'd recommend taking a look at some literature for help in dealing with this. A good start is here: Hurther, D., & Lemmin, U. (2001). A correction method for turbulence measurements with a 3D acoustic Doppler velocity profiler. Journal Of Atmospheric And Oceanic Technology, 18(3), 446–458.

I've looked at the shape you are seeing in the turbulence profiles, and I'm fairly well convinced it is not due primarily to noise. This leaves probe calibration (i.e. the physical geometry of the probe head not quite matching the calibrated geometry) and some intricacies of where and what the Vectrino II is measuring as the best explanations for the shape.

I'm working on trying to figure this out, but I unfortunately have another project which is taking precedence right now.

P.J.