Cavity Flow

Data Evaluation

The HDF5 data format can be read by almost any data analysis tool, sch as MATLAB (external page http://ch.mathworks.com/help/matlab/ref/hdf5read.html)
We prefer Python and developed the pyFlowStat module. It can be used to easily read and plot the PIV data. However, a sample MATLAB code is provided below.

The module is found here: external page https://github.com/ETH-BuildingPhysics/pyFlowStat

Make sure to install the Python HDF5 library: external page http://www.h5py.org/

If you don't have a python distribution installed already, the Anaconda distribution is a good place to start: external page http://continuum.io/downloads
It includes the editor Spyder, a programm similar to the MATLAB use interface.

Sample python code:

from pyFlowStat import SurfaceFunctions
from pyFlowStat import SurfacePlotter

import matplotlib.pyplot as plt

import h5py

hdf5filename=r'Cavity2D_Spire05m_TR600Hz.h5'
h5file=h5py.File(hdf5filename)

#To load all frames, uncomment these two lines
#slist=SurfaceFunctions.loadSurfaceList_hdf5(hdf5filename,keyrange='full',createDict=False)
#s0=slits[0]

#To load one frame
s0=SurfaceFunctions.loadSurface_hdf5(h5file,0,keyrange='full')

h5file.close()

fig=plt.figure()
ax=plt.subplot(1,1,1)
im=SurfacePlotter.PlotField(ax,s0,'Uy',vmin=-1.0,vmax=1.0,cmap='RdYlBu')
cb=plt.colorbar(im)
cb.set_label('Uy [m/s]')
ax.set_xlabel('x [mm]')
ax.set_ylabel('y [mm]')
plt.show()