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Running Simulation - Convergence Monitoring - Mass Flow
Mass flow rates are located in directories according to patchMassFlow function object setup in system/flux.fun. Simple script plotFlowRate.gp can plot the mass flow rates during the computation:
set grid
set xlabel "iterations"
set ylabel "mass flow"
set key box above
#set yrange [20:100]
plot "./patchMassFlows_massFlowInlet/0/massFlow" \
using 1:(-$2) with lines title "spiral inlet", \
"./patchMassFlows_massFlowOutlet/0/massFlow" \
with lines title "drafttube outlet", \
"./patchMassFlows_massFlowMXP1_spiral/0/massFlow" \
using 1:($2+$3+$4+$5+$6+$7+$8+$9) with lines title "spiral outlet", \
"./patchMassFlows_massFlowMXP1_rotor/0/massFlow" \
using 1:(-($2+$3+$4+$5+$6+$7+$8+$9)) with lines title "rotor inlet", \
"./patchMassFlows_massFlowMXP2_rotor/0/massFlow" \
using 1:($2+$3+$4+$5+$6+$7+$8+$9) with lines title "rotor outlet", \
"./patchMassFlows_massFlowMXP2_drafttube/0/massFlow" \
using 1:(-($2+$3+$4+$5+$6+$7+$8+$9)) with lines title "drafttube"
reread
pause mouse
Run the script:
# gnuplot plotFlowRate.gp
Figure: Water turbine CFD, mass flow monitoring plot example.
Previous: Potential of a homogeneous Up: Notes on gravitational potential Next: Center of mass of
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Hydrostatic pressure
Let us consider an incompressible fluid at rest in the presence of a homogeneous gravitational field so it is supported by walls of some, possibly open, vessel. Inside a volume of the fluid there is the well known hydrostatic pressure, let us denote it by 
. Assume the fluid has one free8.6 part of its boundary, i.e. one part of its surface forms a level, i.e. plane or its part. Let us denote by 
a position vector8.7 of an arbitrary point of this plane. Hence for 
holds
Notice the relation (![[*]](https://www.cfdsupport.com/wp-content/uploads/2022/02/crossref.png "Node105 27")
) is valid inside the volume of the fluid only. If we need to extend its domain, it is necessary to assure zero values for outside of the volume of the fluid. For instance, this is satisfied naturally, if we consider 
a constant scalar field but vanishing outside the volume of the fluid.
. Assume the fluid has one free8.6 part of its boundary, i.e. one part of its surface forms a level, i.e. plane or its part. Let us denote by a position vector8.7 of an arbitrary point of this plane. Hence for holds
Notice the relation () is valid inside the volume of the fluid only. If we need to extend its domain, it is necessary to assure zero values for outside of the volume of the fluid. For instance, this is satisfied naturally, if we consider a constant scalar field but vanishing outside the volume of the fluid.
Previous: Potential of a homogeneous Up: Notes on gravitational potential Next: Center of mass of