Absence of a term in adjointShapeOptimizationFoam outlet boundary conditions

robyTKD · April 8, 2013, 09:02

Hi Foamers,

I have a question about boundary conditions of adjointShapeOptimizationFoam. In particular, following Othmer's procedure in A continuous adjoint formulation for the computation of topological and surface sensitivities of ducted flows, boundary conditions for the Outlet are:

$q = \textbf{u} \cdot \textbf{v} + u_n v_n + \nu (\textbf{n} \cdot \nabla) u_n + \frac{\partial J_{\Gamma}}{v_n}$

$0 = v_n \textbf{u}_t + \nu (\textbf{n} \cdot \nabla) \textbf{u}_t + \frac{\partial J_{\Gamma}}{\textbf{v}_t}$

but I can't find $\nu (\textbf{n} \cdot \nabla) \textbf{u}_t$ and $\nu (\textbf{n} \cdot \nabla) u_n$ in adjointOutletPressureFvPatchScalarField.C and adjointOutletVelocityFvPatchScalarField.C.

Are they neglected because they are irrelevant or is simply the normal gradient of adjoint velocity forced to be null?

Best regards,
Roberto

Dome · April 10, 2013, 07:05

Hi Roberto!
I have exactly the same doubt, since in the code:

Code:

operator==((phiap/patch().magSf() - 1.0)*phip/patch().magSf() + (Up & Uap));

and

Code:

vectorField::operator=(phiap*patch().Sf()/sqr(patch().magSf()) + UtHat);

there isn't any "normal gradient" term.

Let's hope for some help

Domenico

fumiya · January 3, 2016, 01:13

Hi,

You can find how to implement these terms in the following document:

Description of adjointShapeOptimizationFoam and how to implement new objective functions
http://www.tfd.chalmers.se/~hani/kur...ortAdjoint.pdf

Best regards,
Fumiya

April 8, 2013, 09:02	Absence of a term in adjointShapeOptimizationFoam outlet boundary conditions	#1
robyTKD Member Roberto Pieri Join Date: Feb 2012 Location: Milan Posts: 57 Rep Power: 14	Hi Foamers, I have a question about boundary conditions of adjointShapeOptimizationFoam. In particular, following Othmer's procedure in A continuous adjoint formulation for the computation of topological and surface sensitivities of ducted flows, boundary conditions for the Outlet are: $q = \textbf{u} \cdot \textbf{v} + u_n v_n + \nu (\textbf{n} \cdot \nabla) u_n + \frac{\partial J_{\Gamma}}{v_n}$ $0 = v_n \textbf{u}_t + \nu (\textbf{n} \cdot \nabla) \textbf{u}_t + \frac{\partial J_{\Gamma}}{\textbf{v}_t}$ but I can't find $\nu (\textbf{n} \cdot \nabla) \textbf{u}_t$ and $\nu (\textbf{n} \cdot \nabla) u_n$ in adjointOutletPressureFvPatchScalarField.C and adjointOutletVelocityFvPatchScalarField.C. Are they neglected because they are irrelevant or is simply the normal gradient of adjoint velocity forced to be null? Best regards, Roberto samiam1000, Dome and Garry974 like this.

April 10, 2013, 07:05		#2
Dome New Member Domenico Sgrò Join Date: Dec 2012 Location: Milan, IT Posts: 2 Rep Power: 0	Hi Roberto! I have exactly the same doubt, since in the code: Code: operator==((phiap/patch().magSf() - 1.0)phip/patch().magSf() + (Up & Uap)); and Code: vectorField::operator=(phiappatch().Sf()/sqr(patch().magSf()) + UtHat); there isn't any "normal gradient" term. Let's hope for some help Domenico

January 3, 2016, 01:13		#3
fumiya Senior Member Fumiya Nozaki Join Date: Jun 2010 Location: Yokohama, Japan Posts: 266 Blog Entries: 1 Rep Power: 19	Hi, You can find how to implement these terms in the following document: Description of adjointShapeOptimizationFoam and how to implement new objective functions http://www.tfd.chalmers.se/~hani/kur...ortAdjoint.pdf Best regards, Fumiya sylvester likes this. __________________ [Personal] Blog: https://caefn.com/ Twitter: https://twitter.com/FumiyaNozaki SlideShare: http://www.slideshare.net/fumiyanozaki96

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