《CFX5.5培训资料》（英文版）Geometry

CFX! Geometry 5.5V5.5.1H

CFX 5.5 V5.5.1H © 2001AEA Technology 3-1

CFX! Introduction Main objective: Build a viable domain(B-rep solids, cutout solids, simple solids) B-rep (boundary representation solids are composed of simple and/or trimmed surfaces Simple(parametric) solids have cubic topology Multiple solids must connect at whole faces Surface and face congruency and parameterization must be kept in mind or the mesh quality will suffer CFX5.5V5.5.1H o 2001AEA Technology

CFX 5.5 V5.5.1H © 2001AEA Technology 3-2 l Main Objective: Build a viable domain (B-rep solids, cutout solids, simple solids) l B-rep (Boundary Representation) solids are composed of simple and/or trimmed surfaces l Simple (Parametric) solids have cubic topology l Multiple solids must connect at whole faces l Surface and face congruency and parameterization must be kept in mind or the mesh quality will suffer

CFX释 Global model tolerance The global model tolerance is the criterion used to evaluate if there is a gap between two geometric entities Default tolerance is 0.005 This is an absolute geometric value(i.e. 1 m cube is accurate to 0.5 cm) A sensible override depends on model size and units For roughly unit geometry the default is reasonable For large geometry in mm a larger value is recommended and vice versa A sensible guide is 1/100 the length of the shortest edge length. CFX5.5V5.5.1H o 2001AEA Technology

CFX 5.5 V5.5.1H © 2001AEA Technology 3-3 l The Global Model tolerance is the criterion used to evaluate if there is a gap between two geometric entities. l Default tolerance is 0.005. l This is an absolute geometric value (i.e. 1 m cube is accurate to 0.5 cm). l A sensible override depends on model size and units. - For roughly unit geometry the default is reasonable. - For large geometry in mm a larger value is recommended, and vice versa. l A sensible guide is 1/100 the length of the shortest edge length

CFX! Geometric Entity: Point Geometry is constructed from the following entities Point(Cyan) CFX-Build creates points automatically when constructing curves. surfaces and solids N B. It is not necessary to construct higher order entities starting with lower order entities 3-4 5.5V5.5.1H

CFX 5.5 V5.5.1H © 2001AEA Technology 3-4 l Geometry is constructed from the following entities: - Point (Cyan). > CFX-Build creates points automatically when constructing curves, surfaces, and solids. N.B. It is not necessary to construct higher order entities starting with lower order entities

CFX! Geometry Entity: Curve · Curve( ellow) A Curve is a general vector function of a single parametric variable. It can have many types of mathematical forms 5.5V5.5.1H

CFX 5.5 V5.5.1H © 2001AEA Technology 3-5 l Curve (Yellow) - A Curve is a general vector function of a single parametric variable. It can have many types of mathematical forms x1

CFX! Geometry Entity: Parametric Surface Parametric surface(Green) a parametric surface is a general vector function of two parametric variables. It can have many types of mathematical forms Parametric surfaces typically have 4 sides P2 Plre 12 P3 5.5V5.5.1H

CFX 5.5 V5.5.1H © 2001AEA Technology 3-6 Geometry Entity: Parametric Surface l Parametric surface (Green) - A parametric surface is a general vector function of two parametric variables. It can have many types of mathematical forms - Parametric surfaces typically have 4 sides

CFX! Geometric Entity: Trimmed Surface Trimmed surface(Magenta) a trimmed surface may have any number of outer bounding edges and can have any number of inner boundaries(holes) 5.5V5.5.1H

CFX 5.5 V5.5.1H © 2001AEA Technology 3-7 l Trimmed surface (Magenta) - A trimmed surface may have any number of outer bounding edges and can have any number of inner boundaries (holes)

CEX! Geometric Entity: Parametric Solid Parametric solid( Blue) Parametric solids are general vector functions of three parametric variables Parametric solids are topologically hexahedral 5.5V5.5.1H

CFX 5.5 V5.5.1H © 2001AEA Technology 3-8 l Parametric solid (Blue) - Parametric solids are general vector functions of three parametric variables - Parametric solids are topologically hexahedral

CFX Geometric Entity: B-rep Solid B-rep solid (white) General solid defined by a set of parametric or trimmed surfaces, which completely enclose it Typically, in CFX-5 the final geometry will be a B-rep solid 5.5V5.5.1H

CFX 5.5 V5.5.1H © 2001AEA Technology 3-9 l B-rep solid (White) - General solid defined by a set of parametric or trimmed surfaces, which completely enclose it - Typically, in CFX-5 the final geometry will be a B-rep solid

CFX! Geometric Entities Single Function Composite of more than one Function C urve Chained curve Parametic Suface Trimmed Suface Parametric Sold B-rep Solid 5.5V5.5.1H

CFX 5.5 V5.5.1H © 2001AEA Technology 3-10