4)Howwillyouisolate a piece of the completephysical system?5)Where will the computational domainbegin and end?Do wehave boundary condition information?Can the boundary condition types accommodate thatinformation?Can we extend the domain to a point where reasonable data exists?)Canitbesimplified orapproximated asa2Doraxi-symmetricproblem?26/253
26/253 4) How will you isolate a piece of the complete physical system? 5) Where will the computational domain begin and end? 6) Can it be simplified or approximated as a 2D or axi-symmetric problem? • Do we have boundary condition information? • Can the boundary condition types accommodate that information? • Can we extend the domain to a point where reasonable data exists?
2.Identify the Domain We Will Model1)How will weisolate a pieceof thecompletephysical system?Cyclone2) Where will the computational domain begin andRiserend?Aretheboundary condition types appropriate?Do we have boundary conditioninformation atthese boundaries?Is the domainappropriate?L-valveGas3)Can it be simplified or approximated as a 2D oraxisymmetricproblem?Example:CycloneSeparator27/253
27/253 2.Identify the Domain We Will Model 1) How will we isolate a piece of the complete physical system? Example: Cyclone Separator 2) Where will the computational domain begin and end? 3) Can it be simplified or approximated as a 2D or axisymmetric problem? Gas Riser Cyclone L-valve Gas Are the boundary condition types appropriate? Do we have boundary condition information at these boundaries? Is the domain appropriate?
3.Design and Create the Grid1）Canweuseaquad/hex（四边形的/六面体的）gridorshouldweuseatri/tet（三角形/四面体）gridorhybridgrid?Howcomplexisthegeometryand flow?2) What degree of grid resolution is required in each region ofthe domain?TriangleQuadrilateral三角形四边形Is the resolution sufficient for the geometry?.Can we predict regions with high gradients?.Will we use adaption to add resolution?TetrahedronHexahedron四面体六面体3)Do wehave sufficientcomputer memory?How many cells are required?Prism/wedgePyramidHow many models will be used?金字塔五面体28/253
28/253 3.Design and Create the Grid 2) What degree of grid resolution is required in each region of Triangle the domain? 三角形 Quadrilateral 四边形 Tetrahedron 四面体 Pyramid 金字塔 Hexahedron 六面体 1) Can we use a quad/hex (四边形的/六面体的) grid or should we use a tri/tet (三角形/四 面体) grid or hybrid grid? 3) Do we have sufficient computer memory? Is the resolution sufficient for the geometry? Can we predict regions with high gradients? Will we use adaption to add resolution? How many cells are required? How many models will be used? How complex is the geometry and flow? Prism/wedge 五面体
nodecellcenterfacecellnodessimple 2DgridSome basic gridedgeterminologycellfacesimple3D grid29/253
29/253 Some basic grid terminology
Mesh TerminologyCellControl volumeCell centerLocation where cell data is storedFaceBoundary of a cell (2D or 3D)EdgeBoundary of a face (3D)NodeGrid pointCell threadGrouping of cellsFace threadGrouping of facesNode threadGrouping of nodesDomainA grouping of node, face, and cell threads30/253
30/253 Cell Control volume Cell center Location where cell data is stored Face Boundary of a cell (2D or 3D) Edge Boundary of a face (3D) Node Grid point Cell thread Grouping of cells Face thread Grouping of faces Node thread Grouping of nodes Domain A grouping of node, face, and cell threads Mesh Terminology