Hackthon Problems   CHIMAD Team  5 Karim  Ahmed  (INL)  and  Sudipta Biswass (Purdue) Under  supervision  of   Daniel  Schwen and  Larry  Aagesen (INL)   

Multiphysics Object-Oriented Simulation Environment (MOOSE)   Ø MOOSE is a massively parallel finite element framework suitable for solving multiphysics problems. Ø MOOSE is a winner of the 2014 R&D 100 award. MOOSE currently meets all Nuclear Quality Assurance Level 1 (NQA-1) requirements. Ø MOOSE is now open source software that can be downloaded freely from GitHub. Ø MOOSE has built-in time and mesh adaptivity, it is dimension agnostic and automatically parallel. An  illustration  of  the   anatomy  of  MOOSE.   

Weak  form  of  the  kinetic  equations   1 2 1 2 ( , ,...., ,...., ) , , ( , ,...., ,...., ) , 1, 2.... . ( , ) , ( , ) , 0, , ( , ) , 0, , p c p c c f c c c c t f c F L L p t f c c c c t t α α α η α α α α η η η µ κ µ η η η η δ κ η α α δη η µ φ φ κ φ κ φ φ µ φ µ φ η φ ∂ = − ∇ ∂ ∂ = ∇⋅ ∇ ∂ ∂ ⎡ ⎤ ∂ = − = − − ∇ ∀ = ⎢ ⎥ ∂ ∂ ⎣ ⎦ ∂ ⎛ ⎞ − − ∇ ∇ + < ∇ ⋅ > = ⎜ ⎟ ∂ ⎝ ⎠ ∂ ⎛ ⎞ + ∇ ∇ − < ∇ ⋅ >= ⎜ ⎟ ∂ ⎝ ⎠ ∂ ⎛ ∂ M n M M n , ( , ) , 0 , 1, 2.... . f L L L p η α η α α φ κ η φ κ η φ α α η ⎛ ⎞ ∂ ⎞ + + ∇ ∇ − < ∇ ⋅ > = ∀ = ⎜ ⎟ ⎜ ⎟ ∂ ⎝ ⎠ ⎝ ⎠ n Strong  form Varitional  (Weak)  form 

Implementation  in  MOOSE Ø Linear Lagrange discretization of the kinetic equations employing four-node quadrilateral elements in 2D Ø The time integration was carried out via a second-order Backward Differentiation Formula (BDF2). Ø The nonlinear system is solved using the Newton method; where in each nonlinear iteration the linear system is solved iteratively using a Krylov method (GMRES). Ø The T and sphere meshes were created using CUBIT 

Prob1-­‐Periodic  BC Phase  fraction   increases  with  time.   Total  free  energy   decreases  with  time.   

Prob1-­‐Zero-­‐flux  BC 

Prob1-­‐Sphere Total  free  energy   decreases  with  time.   

Implementation  in  MOOSE Ø Used DerivativeParsedMaterial and Parsed kernels to model free energy and implement CH equation Ø For Problem 2 developed material to implement free energy and all it’s derivatives w r.t concentration and order parameters Ø Developed an action to create kernels for all the order parameters 

Prob2-­‐Free  energy Due  to  Numerical  Instabilities   solution  had  convergence  issues 

Prob2-­‐Periodic 

Prob2-­‐No  Flux 

Prob2-­‐ T  mesh