myimagelib.corrLib.energy_spectrum

myimagelib.corrLib.energy_spectrum(pivData, d=8.25)

Compute energy spectrum (E vs k) from pivData.

Parameters

• pivData – piv data

• d – sample spacing. This is the distance between adjacent samples, for example, velocities in PIV. The resulting frequency space has the unit which is inverse of the unit of d. The default unit of d is um.

Returns

energy spectrum, DataFrame (k, E)

Edit

10192020

add argument d as sample spacing

11112020

add area constant, see details here

11302020

The energy spectrum calculated by this function shows a factor of ~3 difference when comparing int E(k) dk with v**2.sum()/2