# externalWallHeatFluxTemperature in turbulence models

 Register Blogs Members List Search Today's Posts Mark Forums Read

 June 27, 2012, 06:40 externalWallHeatFluxTemperature in turbulence models #1 New Member   Join Date: Mar 2010 Posts: 21 Rep Power: 7 I wish to apply a nonuniform heat-transfer-coefficient boundary coefficient to a wall. I have used the following boundary condition for temperature: my-boundary { type externalWallHeatFluxTemperature; K basicThermo; KName none; Ta 300; value 300; gradient 0; h nonuniform List .... } If I specify 'h' with units [W/m2/K] I get far too much heat leaving the boundary. I'm having trouble following the units through externalWallHeatFluxTemperatureFvPatchScalarField. C 00210 q = (Ta_ - *this)*h_; I think this implies [q] = [K - K]*[W/m2/K] = [W/m2]. Then... 00224 if (q[i] > 0) //in 00225 { 00226 this->refGrad()[i] = q[i]/K(*this)()[i]; 00227 this->refValue()[i] = 0.0; 00228 this->valueFraction()[i] = 0.0; 00229 } 00230 else //out 00231 { 00232 this->refGrad()[i] = 0.0; 00233 this->refValue()[i] = KDelta[i]*q[i] + patchInternalField()()[i];00234 this->valueFraction()[i] = 1.0; 00235 } For the heat input case, I see [refGrad]=[W/m2] / [W/m/K] = [K/m], which is good. For the heat output case, I think the units of kDelta are [W/m/K]*[1/m]=[W/m2/K] based on mesh.surfaceInterpolation.c and 00202 scalarField KDelta(K(*this)*patch().deltaCoeffs()); Doesn't this imply the units of refValue are [refValue] = [W/m2/K] * [W/m/K] + [K] ? Is this a bug or have I mis-understood something? Thanks, irw Last edited by irw; June 27, 2012 at 09:17.

 July 20, 2013, 05:29 #2 New Member   sebastian n Join Date: Nov 2012 Posts: 17 Rep Power: 4 Hi foamers, first i want to say that i am interested in getting the problem solved from the first post "If I specify 'h' with units [W/m2/K] I get far too much heat leaving the boundary" too. Can anyone explain the question from the first post? My question deals with the problem how to read out data for Ta from a .dat file; is it in general possible? type externalWallHeatFluxTemperature; K solidThermo; // solidThermo or lookup q uniform 1000; // Heat flux / [W/m2] Ta uniform 300.0; // Tambient temperature /[K] h uniform 10.0; // Heat transfer coeff /[W/Km2] value uniform 300.0; // Initial temperature / [K] KName none; Can i combine this type with: { type uniformFixedValue; uniformValue tableFile; tableFileCoeffs { fileName "inlet.dat"; outOfBounds warn; } } Thank you very much!

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post philippose OpenFOAM Running, Solving & CFD 30 August 4, 2010 10:26 gmwsy FLUENT 3 June 19, 2009 06:08 Wen Long Main CFD Forum 3 May 15, 2009 09:52 spatialtime CFX 4 April 24, 2009 05:25 Sima Baheri Phoenics 0 January 6, 2007 05:08

All times are GMT -4. The time now is 15:25.