Efficiency in dynamic flow visualization

ParaView Support
1

Hello everyone,
My goal is to visualize a dynamic flow simulation of a petroleum reservoir, to do that I use unstructured vtk grid format (.vtu) and to see the change in dynamic properties over time I use (.pvd). So I create several .vtu files, and combine them into a Collection using .pvd format.
It works, but it is not efficient and takes a lot of time to read each time step.
The main reason why it is not efficient is that my grid is static and it weights over 100Mb, while properties for each timestep weight only around 5 Mb, so to be more efficient I need to read only properties for each timestep, I don’t need to reread my static grid, because it does not change from timestep to timestep, but I don’t know how to do that, and currently it reads ~105 Mb for each timestep.

2

it seems I found the solution, here the example on two cells, and 3 timesteps, hope it will work on bigger models either

 <?xml version="1.0"?>
<VTKFile type="UnstructuredGrid" version="0.1" byte_order="LittleEndian">
<UnstructuredGrid TimeValues="0 1 2">
<Piece NumberOfPoints="16" NumberOfCells="2">
<PointData>
</PointData>
<CellData>
<DataArray type="Float64" Name="volume" Format="ascii" TimeStep="0">
.169 .222
</DataArray>
<DataArray type="Float64" Name="volume" Format="ascii" TimeStep="1">
.111 .222
</DataArray>
<DataArray type="Float64" Name="volume" Format="ascii" TimeStep="2">
.333 .144
</DataArray>
</CellData>
<Points>
<DataArray type="Float64" Name="Points" NumberOfComponents="3" format="ascii" RangeMin="0" RangeMax="2" TimeStep="0 1 2">
17.36998185	0	2799.574717
23.5622183	0	2802.517717
23.5622183	5	2802.517717
17.36998185	5	2799.574717
15.2236936	0	2804.090627
21.41593006	0	2807.033627
21.41593006	5	2807.033627
15.2236936	5	2804.090627
23.5622183	0	2802.517717
30.24098433	0	2805.874903
30.24098433	5	2805.874903
23.5622183	5	2802.517717
21.41593006	0	2807.033627
27.98874185	0	2810.338915
27.98874185	5	2810.338915
21.41593006	5	2807.033627
</DataArray>
</Points>
<Cells>
<DataArray type="Int64" Name="connectivity" format="ascii" RangeMin="0" RangeMax="15" TimeStep="0 1 2">
0 1 2 3 4 5 6 7
8	9	10	11	12	13	14	15
</DataArray>
<DataArray type="Int64" Name="offsets" format="ascii" RangeMin="4" RangeMax="8" TimeStep="0 1 2">
8 16
</DataArray>
<DataArray type="UInt8" Name="types" format="ascii" RangeMin="42" RangeMax="42" TimeStep="0 1 2">
12 12
</DataArray>
</Cells>
</Piece>
</UnstructuredGrid>
</VTKFile>