[silencebreak]

Hey,

My Problem is as followed:
I've got a pipe with an inflowing fluid (water). I want to change with groovyBC the area of the inflow and the inflow velocity of the patch during the run on a time dependency.
Actually it's a "closing" of the inlet, so the area of my inflow is reduced over the time, but my flow rate needs to be constant so the velocity has to speed up.

I tried to make it more understandable with a drawing:


So my guess is to put the patches of the inflow in alpha.water and U with a groovyBC. Because of the circularity it's a bit difficult to do, but I think the definition in U could be right. My main problem is the definition of my alpha.water.
(actually I analyze the flow in both ways so my inflow is on patch outlet)

What I tried so far:
I made a dependency that on the patch outlet in alpha.water that every cell value between 0.5 and 1.1 should be used for my field U.

alpha.water

outlet
    {
        type            groovyBC;
        variables       "Oberkante=-1751.518895;Unterkante=-1765.558895;close=pos().z-0-(14.04*time()*1.0);";
valueExpression "(pos().z < close) ? 1 : 0";
        factionExpression "(pos().z < close) ? 1 : 0";
        value           uniform 1;

The Patch starts at the absolute coordinates on position "Oberkante" and ends on "Unterkante" on the z-achsis. So the movement is against the z-achsis down.

U

type            groovyBC;
        value           uniform (0 0 0);
        aliases         {alphaWater alpha.water;};
        variables       "alphaFromPatchOutlet{outlet}=alphaWater;neededPatchArea=alphaFromPatchOutlet*min(0.5,2);aHight=(0.001/((4/3)*14.04*time()*1.0*sqrt(2*7.02*14.04*time()*1.0-pow(14.04*time()*1.0,2))));";
        valueExpression "-normal()*aHight*alphaFromPatchOutlet";

I think I could ease the function in U it a little bit up with the integrate function?

For now the main problem is the definition of alpha.water for the patch outlet. Does anyone have a guess where the Problem in the definition could be?

Many thanks in advance,
Oli

[hr_nt]

Originally Posted by silencebreak

Hey,

My Problem is as followed:
I've got a pipe with an inflowing fluid (water). I want to change with groovyBC the area of the inflow and the inflow velocity of the patch during the run on a time dependency.
Actually it's a "closing" of the inlet, so the area of my inflow is reduced over the time, but my flow rate needs to be constant so the velocity has to speed up.

I tried to make it more understandable with a drawing:


So my guess is to put the patches of the inflow in alpha.water and U with a groovyBC. Because of the circularity it's a bit difficult to do, but I think the definition in U could be right. My main problem is the definition of my alpha.water.
(actually I analyze the flow in both ways so my inflow is on patch outlet)

What I tried so far:
I made a dependency that on the patch outlet in alpha.water that every cell value between 0.5 and 1.1 should be used for my field U.

alpha.water

outlet
    {
        type            groovyBC;
        variables       "Oberkante=-1751.518895;Unterkante=-1765.558895;close=pos().z-0-(14.04*time()*1.0);";
valueExpression "(pos().z < close) ? 1 : 0";
        factionExpression "(pos().z < close) ? 1 : 0";
        value           uniform 1;

The Patch starts at the absolute coordinates on position "Oberkante" and ends on "Unterkante" on the z-achsis. So the movement is against the z-achsis down.

U

type            groovyBC;
        value           uniform (0 0 0);
        aliases         {alphaWater alpha.water;};
        variables       "alphaFromPatchOutlet{outlet}=alphaWater;neededPatchArea=alphaFromPatchOutlet*min(0.5,2);aHight=(0.001/((4/3)*14.04*time()*1.0*sqrt(2*7.02*14.04*time()*1.0-pow(14.04*time()*1.0,2))));";
        valueExpression "-normal()*aHight*alphaFromPatchOutlet";

I think I could ease the function in U it a little bit up with the integrate function?

For now the main problem is the definition of alpha.water for the patch outlet. Does anyone have a guess where the Problem in the definition could be?

Many thanks in advance,
Oli

Hi did you manage to run the simulation with this condition ? I am looking at a similar situation where I want my inlet patch to pulsate alpha where the inlet produces gases for sometime and then produces no gas.