Hi Alexander,
<[EMAIL PROTECTED]> writes:
> dunno if that's your problem, but the usage of assert seems to be mistaken
> here.
>
> Asserting for (dI < dO) means assuring that state. Only if (dI < dO)
> evaluates to false, your message is given. But then the message "Inlet
> smaller than outlet!" suggests the opposite to me. Unless you mean
> "Inlet should be smaller than outlet."
Your are right! I got a bit confused, I'm sorry. Anyway, a problem
(bug) remains still: Instead of giving the assertion text (Inlet smaller
than outlet) OM calculates some values and gives no warning/error
message what so ever instead it says:
>>> runScript("model.mos")
"true
true
record
resultFile = "Idiot.Test_res.plt"
end record
Thanks for your support
Dieter
>
> Greetings
> Alexander
>
>
> -----Ursprüngliche Nachricht-----
> Von: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Im Auftrag von dieter
> Gesendet: Dienstag, 3. Juni 2008 22:03
> An: Modelica Association
> Betreff: Problem with "assert"
>
> Hi,
>
> unfortunately there seems to be another bug: When I'm running below
> model with
>
> simulate( Idiot.Test, stopTime = 6000/60,numberOfIntervals=50);
>
> it gives me some 50 result steps, so far so good. But when I just
> comment out the (here logically irrelevant) assert function below, OM
> gives me only 2 result steps!
>
> 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 = 5e-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 = 4e5;
> 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;
> Real qqq;
> 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;
> qqq = qq / q;
> inPort.flowrate = if q < qt then 0 else qq;
> end PumpStage;
>
> model Test
> parameter Real pressure = ambientPressure;
> inner Fluid fluid(viscosity = 3.3e-3, density = 850);
> Nozzle nozzle;
> Ambience ambience;
> PressureBoundary pressureBC( p = 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, pressureBC.port);
> end Test;
> end Idiot;
