Adrian Pop <[EMAIL PROTECTED]> writes:
Hi,
> This command actually works but it takes
> a lot of time (~34 minutes on my computer).
>> simulate(Idiot.Test,stopTime=6000/60,numberOfIntervals=20)
Oooh I see, I never had the patience 8-)
> I will need to have a look at this, but as far as
> I can see, the solver takes extremely small steps,
> that's why it takes a lot of time to run the
> simulation.
Strangely, it helps removing numberOfIntervals!
Good luck
Dieter
>
> Cheers,
> Adrian Pop/
>
> dieter wrote:
>> Hi,
>>
>> when I run the small model below with:
>>
>> simulate(Idiot.Test,stopTime=5000/60,numberOfIntervals=20)
>>
>> it produces a result file. But when I run it with:
>>
>> simulate(Idiot.Test,stopTime=6000/60,numberOfIntervals=20)
>>
>> the executable seems to stick in an infinite loop.
>>
>> I hope somebody can have a look at it or has some idea.
>>
>> Thanks
>> Dieter
>>
>> ------------------------------------------------------------
>> package Idiot
>> //import Modelica.Constants.*;
>>
>> final constant Real pi = 3.1415926;
>> final constant Real ambientPressure = 101325;
>>
>> connector Port
>> Real pressure;
>> flow Real flowrate;
>> end Port;
>> class Fluid "Water is the default" parameter
>> Real density = 1e3;
>> parameter Real viscosity = 1e-3;
>> end Fluid;
>>
>> partial model TwoPorts
>> outer parameter Fluid fluid;
>> Port inPort, outPort;
>> equation
>> inPort.flowrate + outPort.flowrate = 0;
>> end TwoPorts;
>>
>> partial model Conduit "generic flow resistance element"
>> extends TwoPorts;
>> parameter Real referenceDiameter = 8e-3 "may it be the in or
>> outPort diameter"; //protected
>> final parameter Real d = referenceDiameter; // final excludes them from
>> the GUI
>> final parameter Real A = pi/4 * d^2;
>> Real dp "pressure loss";
>> Real r,m, q, z;
>> Real lossFactor;
>> Real v "velocity";
>> Real Re "Reynolds No";
>> equation
>> r = fluid.density;
>> m = fluid.viscosity;
>> q = inPort.flowrate;
>> z = lossFactor;
>> v = q / A;
>> Re = v * d / ( m / r);
>> dp = z * r/2 * v^2;//genericPressureLoss(z, v, r);
>> inPort.pressure = outPort.pressure + dp;
>> end Conduit;
>>
>> model Nozzle "also usable for broken (deburred) inlet
>> opening" extends Conduit;
>> parameter Real inDiameter = 1e6; // "approximation of a broken (deburred)
>> inlet from ambience";
>> protected
>> final parameter Real dI = inDiameter;
>> final parameter Real dO = referenceDiameter;
>> //algorithm
>> equation
>> // assert( dI < dO, "Inlet smaller than outlet! Use a diffuser instead");
>> lossFactor = 1.04 - (dO/dI)^4; // loss factor includes the acceleration
>> work r/2 v^2
>> // 0.04 is from VDI Wärematlas 7th issue
>> // 0.05 from Dubbel 16th issue
>> // annotation (Documentation (info= "The nozzle is also a good
>> // approximation for deburred intakes z = 0.05, rounded intake: z = 0.005
>> // to 0.05, very sharp edged intakes: up to z = 0.5 (taken from VDI
>> // Wärmeatlas 7th issue)")); end Nozzle;
>>
>> model Ambience
>> Port port;
>> equation
>> port.pressure = ambientPressure;
>> end Ambience;
>>
>> model PressureBoundary
>> parameter Real p = 3e5;
>> Port port;
>> equation
>> port.pressure = p + ambientPressure;
>> end PressureBoundary;
>>
>> model PumpStage
>> // TODO: leakage! TwoPorts is tight!
>> extends TwoPorts;
>> parameter Real V = 0.8054e-6 "0.8054e-6 VDO, 2.05e-6: GKN";
>> parameter Real s = 0.03e-3 "tooth gap";
>> parameter Real b = 6e-3 "Stage breadth";
>> parameter Real l = 0.4e-3 "effective tooth gap length";
>> parameter Real e0 = 0.975 "volumetric efficiency at '0 bar'";
>> //protected
>> Real qt; // tooth leakage
>> Real n "revs";
>> Real m, dp, q, qq;
>> equation
>> m = fluid.viscosity;
>> n = time;
>> dp = outPort.pressure - inPort.pressure;
>> qt = b*s * dp*s^2 / ( 12*m*l);
>> q = e0*V*n;
>> qq = q - qt;
>> inPort.flowrate = if q < qt then 0 else qq;
>> end PumpStage;
>>
>> model Test
>> inner Fluid fluid(viscosity = 3.3e-3, density = 850);
>> Nozzle nozzle;
>> Ambience ambience;
>> PressureBoundary pressure;
>> PumpStage pump;
>> equation
>> connect( ambience.port, nozzle.inPort);
>> connect( nozzle.outPort, pump.inPort);
>> // connect(ambience.port, pump.inPort);
>> // connect( ambience.port, pump.inPort);
>> connect( pump.outPort, pressure.port);
>> end Test;
>> end Idiot;
