# sonicTurbDyMEngineFoam

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 January 29, 2013, 04:23 Opening soon the exhaust valve "sonicTurbDyMEngineFoam" #1 Senior Member   Sasan Ghomi Join Date: Sep 2012 Location: Iran - Tehran Posts: 185 Rep Power: 6 Hi every body, I have a problem with a case for coldFlow in an internal combustion engine (sonicTurbDyMEngineFoam )....the exhaust valve opens early (about 0.005 (s) ).Can any one help me???? How do I correct it??? thanks, Sasan Last edited by sasanghomi; January 29, 2013 at 06:28.

 January 29, 2013, 05:35 #2 Super Moderator   Bruno Santos Join Date: Mar 2009 Location: Lisbon, Portugal Posts: 9,679 Blog Entries: 39 Rep Power: 103 Greetings Sasan, Can you please provide more information? The reason I ask is because you're not providing enough information, as indicated in this thread: How to give enough info to get help Best regards, Bruno PS: don't mind about the other post with strange characters, it was just a spammer... __________________ OpenFOAM: FAQ | Getting started Forum: How to get help, to post code/output and forum guide What am I doing/planning: blog/wiki Read this before sending me PM

January 29, 2013, 07:16
Opening soon the exhaust valve "sonicTurbDyMEngineFoam"
#3
Senior Member

Sasan Ghomi
Join Date: Sep 2012
Location: Iran - Tehran
Posts: 185
Rep Power: 6
Hi wyldckat ,
Thank you very much.
I am running a case that it simulates the cold flow in an internal combustion engine.
The solver is sonicTurbDyMEngineFoam.The rotational velocity is (rpm=1500), So the total time for a cycle of the engine is 0.08(s).I expect that the exhaust valve opens at 0.06(s)
but when I plot the mass flow versus time at the exhaust port I saw that the exhaust valve opened at 0.055(s).How do I can correct this problem???please any one help me....

The engineGeometry is as below :

Code:
```/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM Extend Project: Open Source CFD        |
|  \\    /   O peration     | Version:  1.6-ext                               |
|   \\  /    A nd           | Web:      www.extend-project.de                 |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
version     2.0;
format      ascii;
class       dictionary;
object      engineGeometry;
}

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

conRodLength    conRodLength [0 1 0 0 0 0 0] 0.147;

bore            bore [0 1 0 0 0 0 0] 0.092;

stroke          stroke [0 1 0 0 0 0 0] 0.075;

clearance       clearance [0 1 0 0 0 0 0] 0.015;

rpm             rpm [0 0 -1 0 0 0 0] 1500;

engineTopoChangerMesh  simpleEngineTopoFvMesh;

// Between -deformAngle and deformAngle the piston motion is done
// using deformation and not layering
deformAngle     10;

valvePosTol     1e-4;

layeredMesh     yes;
checkMesh       yes;

piston
{
patch               piston;

coordinateSystem
{
type            cartesian;
origin          (0 0 0);
axis            (0 0 1);
direction       (0 1 0);
}

minLayer        0.0005;
maxLayer        0.001;
}

valveSplitPoint     (0.003 0 0);    // For the converter
// Two-valve engine valves are split on x
// Four valve engines are split into 4 quadrants in the x-y plane

valves
(
intakeValve
{
// Valve coordinate system
coordinateSystem
{
type            cylindrical;
origin          (-0.025 0 0);
axis            (0 0 1);
direction       (0 1 0);
}

// Patch  and zone names
bottomPatch             valve1;
poppetPatch             valve2;
stemPatch               valveStem1;

curtainInPortPatch      valveCurtainPort1;
curtainInCylinderPatch  valveCurtainCyl1;

detachInCylinderPatch   valveDetachCyl1;
detachInPortPatch       valveDetachPort1;

detachFaces
(
2593
2595
2597
2599
2601
2603
2605
2607
2609
2611
2613
2615
2617
2619
2621
2623
2625
2627
2629
2630
);

// Vertex on edge of the step.  For the converter
stemEdge            (-0.04 0 -0.0075);

// Valve diameter
diameter            0.03;

// Minimum valve lift
minLift             0.00025;

// Layer thickness
minTopLayer         0.0005;
maxTopLayer         0.001;

minBottomLayer      0.0005;
maxBottomLayer      0.001;

// Lift Profile
liftProfileFile "intakeLiftProfileFile";
}

exhaustValve
{
// Valve coordinate system
coordinateSystem
{
type            cylindrical;
origin          (0.025 0 0);
axis            (0 0 1);
direction       (0 1 0);
}

// Patch  and zone names
bottomPatch             valve3;
poppetPatch             valve4;
stemPatch               valveStem2;

curtainInPortPatch      valveCurtainPort2;
curtainInCylinderPatch  valveCurtainCyl2;

detachInCylinderPatch   valveDetachCyl2;
detachInPortPatch       valveDetachPort2;

detachFaces
(
4854
4856
4858
4860
4862
4864
4866
4868
4870
4872
4874
4876
4878
4880
4882
4884
4886
4888
4890
4891
);

// Vertex on edge of the step.  For the converter
stemEdge           (0.04 0 -0.0075);

// Valve diameter
diameter            0.03;

// Minimum valve lift
minLift             0.00025;

// Layer thickness
minTopLayer         0.0005;
maxTopLayer         0.001;

minBottomLayer      0.0005;
maxBottomLayer      0.001;

// Lift Profile
liftProfileFile "exhaustLiftProfileFile";
}

);

// ************************************************************************* //```
An image of the case is attached.

Thanks,
Sasan.

Attached Images
 engine.jpg (12.0 KB, 48 views)

 January 29, 2013, 09:18 #4 Senior Member   Join Date: Oct 2009 Posts: 136 Rep Power: 9 The exhaust will open when the lift exhaust valve lift exceeds 0.0025 as specified in your dictionary. So it depends on your valve lift profile. cheers peter sasanghomi likes this.

 January 29, 2013, 09:39 #5 Senior Member   Sasan Ghomi Join Date: Sep 2012 Location: Iran - Tehran Posts: 185 Rep Power: 6 Thanks for your reply peter, Can you give me any sources about describtion of minimum valve lift and valve lift profile?? Can you explain them?? thanks, Sasan. sasanghomi@yahoo.com Last edited by sasanghomi; January 30, 2013 at 03:37.

 October 4, 2016, 20:11 #6 New Member   EngineJob Join Date: Jun 2016 Location: Brazil Posts: 2 Rep Power: 0 hi, i have a problem with this solver too. The error is: Code: ``` --> FOAM FATAL ERROR: found boundary face in valve detach definition for valve 1. This is not allowed. Detach faces: 24 ( 12316 12317 12318 12319 12320 12321 12322 12323 12324 12325 12326 12327 12328 12329 12330 12331 12332 12333 12334 12335 12336 12337 12338 12339 ) nInternalFaces: 12190 From function void simpleEngineTopoFvMesh::addZonesAndModifiers() in file simpleEngineTopoFvMesh/addSimpleEngineTopoFvMeshModifiers.C at line 188.``` Searching for this function i have found it: Code: ```// Create a detach zone if ( valves_[valveI].detachInCylinderPatchID().active() && valves_[valveI].detachInPortPatchID().active() && valves_[valveI].detachFaces().size() > 0 ) { Info<< "Adding detach boundary for valve " << valveI + 1 << endl; const vectorField& areas = Sf().internalField(); const labelList& df = valves_[valveI].detachFaces(); boolList flip(df.size(), false); const vector& pistonAxis = piston().cs().axis(); forAll (df, dfI) { if (isInternalFace(df[dfI])) { if ((areas[df[dfI]] & pistonAxis) > 0) { flip[dfI] = true; } } else { FatalErrorIn ( "void simpleEngineTopoFvMesh::" "addZonesAndModifiers()" ) << "found boundary face in valve detach definition" << " for valve " << valveI + 1 << ". This is not allowed. Detach faces: " << df << " nInternalFaces: " << nInternalFaces() << abort(FatalError); } }``` probably i have some problems with the mesh, right ? How do i do the mesh at the detach zone ?

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