# alpha or alpha1 in interFoam & interDyMFoam

 User Name Remember Me Password
 Register Blogs Members List Search Today's Posts Mark Forums Read

 September 8, 2009, 06:45 alpha or alpha1 in interFoam & interDyMFoam #1 New Member   T Somerville Join Date: May 2009 Posts: 10 Rep Power: 17 From the damBreak tutorial of version 1.5, fvSchemes looks like: gradSchemes { default Gauss linear; grad(U) Gauss linear; grad(gamma) Gauss linear; } divSchemes { div(rho*phi,U) Gauss limitedLinearV 1; div(phi,gamma) Gauss vanLeer; div(phirb,gamma) Gauss interfaceCompression; } Now, I was under the impresssion that gamma was replaced by alpha1 in version 1.6. Yet, here is the same excerpt from v1.6 damBreak tutorial, which contains alpha and alpha1: gradSchemes { default Gauss linear; grad(U) Gauss linear; grad(alpha1) Gauss linear; } divSchemes { div(rho*phi,U) Gauss limitedLinearV 1; div(phi,alpha) Gauss vanLeer; div(phirb,alpha) Gauss interfaceCompression; } and it isn't even consistent - take a look at the same excerpt from interDyMFoam v1.6 gradSchemes { default Gauss linear; grad(U) Gauss linear; grad(alpha) Gauss linear; } divSchemes { div(rho*phi,U) Gauss upwind; div(phi,alpha) Gauss vanLeer; div(phirb,alpha) Gauss interfaceCompression; } So what is the difference between alpha and alpha1. Am I misunderstanding something, or is this a bug? Cheers, Tracy.

 September 9, 2009, 02:54 #2 Senior Member   Join Date: Mar 2009 Posts: 854 Rep Power: 22 alpha1 is the phase fraction of phase 1 in a multi-phase system, alpha in the control dictionaries refers to any phase. The reason for the "inconsistency" is to ensure that the discretisation schemes are the same for all phases. H nepomnyi likes this.

 September 9, 2009, 21:23 #3 New Member   T Somerville Join Date: May 2009 Posts: 10 Rep Power: 17 Thank you. But the "inconsistency" refers to the line grad(alpha1) Gauss linear; in the controlDict of the interFoam tutorial, compared to the line grad(alpha) Gauss linear; in the controlDict of the interDyMFoam tutorial. I'm assuming from your reply that they should both be grad(alpha)?

 September 10, 2009, 02:51 #4 Senior Member   Join Date: Mar 2009 Posts: 854 Rep Power: 22 Ahh OK, I missed that, it should be grad(alpha1) in both cases but as the scheme is set the same as the default it won't make any difference. I will correct this in 1.6.x. Thanks H

 Tags alpha, alpha1, gamma, interdymfoam, interfoam

 Thread Tools Search this Thread Search this Thread: Advanced Search 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 Off Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post azman OpenFOAM Running, Solving & CFD 3 June 7, 2022 04:21 francesco_b OpenFOAM Running, Solving & CFD 9 July 25, 2020 06:36 sxhdhi OpenFOAM Running, Solving & CFD 3 May 5, 2009 21:58 Heiko Gerhauser Main CFD Forum 17 July 25, 2001 14:40 Liaqat Khan Siemens 1 October 27, 2000 04:44

All times are GMT -4. The time now is 08:47.

 Contact Us - CFD Online - Privacy Statement - Top