DNDSR Ideas

Next Step:

• [x] wrap mesh for better access
• [ ] check dist topo and comm with a global BFS data
• [x] start CFV methods
• [x] check on general json parsing
• [x] octree and periodic bc ~~(using CGAL)~~ using nanoflann
• [x] mesh reader: CGNS abutting interface with 1-to-1 face
• [x] CFV limiters
• [x] Euler Solver
• [x] Facial Value output in Euler Solver
• [x] kdtree for euler solver's wall dist finding
• [ ] mesh: automatic global refinement
• [ ] reorganize comm strategy and communication callings
• [x] more bases in CFV
• [x] more functional in CFV
• [x] fully serial mesh partitioning
• [ ] try scotch?
• [x] serialization of euler solver
• [x] restarting of euler solver
• [x] data post-process utility (with VTK?)
• [ ] wrap the mesh and vfv into iterator or range based for
• [ ] wrap array into iterator or range based for
• [ ] wrap derived arrays into iterator or range based for

About Periodic:

• periodic is defined with bnd faces
• periodic makes faces 2x duplicate, and nodes 8x duplicate max

steps in doing periodic ?:

at least in serial reader:

meshinfo:

• coordSerial
• cell2nodeSerial
• bnd2nodeSerial
• cellElemInfoSerial
• bndElemInfoSerial
• bnd2cellSerial

well, when we have this, we need to add something:

• 1. detect face-to-face_donor
• 2. decide node de-duplication, and get new set of nodes_deduplicated
• 3. alter cell2node/bnd2node to point to correct nodes_deduplicated
• 4. coord now stores nodes_deduplicated
• partitioned:
• 5. use faceID to detect cells that are affected by periodic, record them
• 6. mask any mesh->coord[iNode] queries
• 7. in cfv, mask any coord-related (center, quadrature...) queries

the intention is to make topology unique and complete, treating faces with periodic like the inner ones

to ease cell2node query, in parallel:

• create appended physcial_coord
• for affected cells, convert cell2node(pointing to local) to point to physcial_coord (with minus meaning the physical_coord indices) (need a new adj state)
• create means of inverting the process (to get original cell2node(pointing to local) topo)
• when printing vis files, physcial_coord should be appended, and cell2node need to point to those, and coord data on physical_coord should copy those of original coord
• mesh serialization state should be unaffected by periodic (not pointing to appended, or the physical_node_to_actual_node mapping should also be serialized)

findings:

if the periodic mesh is 2xN cell (3x(N+1)nodes), the current face interpolation makes wrong face findings (with less faces created than needed;); this thing could be ignored for now?

new rules:

periodic donor and main must be non-adjacent (not sharing nodes) (main-donor node mapping each pair is not identical) [reasoning: if periodicity needs this, means singularity point, replace this point with a small face with sym condition]

then, record cell2nodePi, and face2nodePi, to augment cell2node ..., and:

nodePi: bit1-bit2-bit3, means [if peri1][if peri2][if peri3]

in the sense of peri-duplicated mesh, node in a cell is different when both cell2node(iCell,ic2n) and cell2nodePI(iCell,ic2n) are different; so use both cell2node and cell2nodePi for inner-cell coord calculation

in the sense of de-duplicated mesh, cell2node(iCell,ic2n) is unique, and points to a coord;

to get interpolate face, the faces are the same when both are true:

• face2node are the same,
• face2nodePi are collaborating: the xor (face2nodePiL_if2n, face2nodePiR_if2n) are the same

face2nodePi are got from the first cell, like face2node faceAtr are got from the first cell, (for de-duplicated faces, could be periodic-donor or main)

to query face-coords in cell, check is is periodic, if donor, face2cell[1] needs the face to trans-back; if main, face2cell[1] needs the face to trans; face2cell[0] is always good

to query other cell-coord through face, if face is periodic main, if cell is face2cell[0] then other cell needs trans back; cell is face2cell[1] then other cell needs trans

About Exporting Static Interfaces

Use pybind11?

Array objects for exporting:

• MPI Top interface
• Adj array (non uniform)
• 3d coord array
• UDof array
• URec array
• Eigen Vec / Mat / Mats array ?
• Rec Matrices array ?

About Increasing Performance:

• using vectorized Riemann solver / face flux
• using face - single - dissipation Riemann Solver
• 4-cached DBV
• SGS init with last du
• start with lower order
• CFL adapt
• RCM? reordering

mesh elevator

• could just use serial
• parallel: need some control on bnd-bnd / node-bnd
• geometrical edge detection: 1. each node has set of norms on bnds; 2. on edge: see if norms of a endpoint is close to normal to the edge(or else dispose of it), which means filtering out those deviates the edge norm too much
• rbf field: nodes include original bnd nodes and new bnd nodes