Changes between Version 31 and Version 32 of Tutorial/ParticleImageVelocimetry


Ignore:
Timestamp:
Jan 21, 2015, 2:31:12 PM (6 years ago)
Author:
vaillant1p
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • Tutorial/ParticleImageVelocimetry

    v31 v32  
    8686The parameters '''[num_Dx]''' and '''[num_Dy] '''define the mesh of the measurement grid, in pixels. Reduce them to get more vectors, but keep in mind that the spatial resolution is limited by the size of the correlation box.
    8787
    88 The PIV operation is conveniently visualised by pressing the button '''[!TestCiv1]''' in the GUI civ. Then the image appear in a new GUI '''view_field''', in which the mouse motion displays the correlation function, which appears in a secondary window, see figure. The resulting vector is shown as a line pointing to the correlation maximum. The corresponding correlation and search boxes are shown in the image. Let us run again PIV with [!CorrBoxSize]=[25 25] and [!SearchBoxSize]=[33,33], limiting ourselves to CIV1, and visualisae the result with '''uvmat'''. Many black vectors (F=-2) are obtained, showing that the search domain is too small, so that the correlation maximum is constrained by the limited search interval. Repeat the operation with [https://servforge.legi.grenoble-inp.fr/projects/soft-uvmat/search?q=wiki%3ASearchBoxSize SearchBoxSize]=[35,33], then the arrows are not black anymore.
     88The PIV operation is conveniently visualised by pressing the button '''[!TestCiv1]''' in the GUI civ. Then the image appear in a new GUI '''view_field''', in which the mouse motion displays the correlation function, which appears in a secondary window, see figure. The resulting vector is shown as a line pointing to the correlation maximum. The corresponding correlation and search boxes are shown in the image. Let us run again PIV with '''[!CorrBoxSize]'''=[25 25] and '''[!SearchBoxSize]'''=[33,33], limiting ourselves to CIV1, and visualisae the result with '''uvmat'''. Many black vectors (F=-2) are obtained, showing that the search domain is too small, so that the correlation maximum is constrained by the limited search interval. Repeat the operation with '''[!SearchBoxSize]'''=[35,33], then the arrows are not black anymore.
    8989
    9090= Masks =