《CFX4培训》（英文版）Lecture 5 Constraints, Patches, Mesh and Analysis

AEATECHNOLoGY ENGINEERING SOFTWAR Lecture 5 CFX-Build Constraints Patches, Mesh and Analysis 5-1 CFX-4 CFX4.3V4.3.1H Introductory Training(Dec 1999

CFX-4 Introductory Training (Dec 1999) 5 -1 CFX-4.3 V4.3.1H Lecture 5 Constraints, Patches, Mesh and Analysis CFX-Build

AEATECHNOLoGY ENGINEERING SOFTWAR Steps in Model creation Geometry build wireframe using points, curves, surfaces and solids Constraints -define constraints for solids with area mismatch Patches define boundary conditions(inlet, outlet, walls) Mesh mesh all surfaces Analysis generate internal volume mesh and geo file 5-2 CFX-4 CFX4.3V4.3.1H Introductory Training(Dec 1999

CFX-4 Introductory Training (Dec 1999) 5 -2 CFX-4.3 V4.3.1H Steps in Model Creation - build wireframe using points, curves, surfaces and solids. - define constraints for solids with area mismatch. - define boundary conditions (inlet, outlet, walls). - mesh all surfaces. -generate internal volume mesh and geo file. Geometry Constraints Patches Mesh Analysis

AEATECHNOLOGY ENGINEERING SOFTWAR Constraints Parent Face used to specify an interface connection between adjacent block faces with unequal areas consistent mesh between two solids Which do not meet at a Whole face Child face 5-3 CFX-4 CFX4.3V4.3.1H Introductory Training(Dec 1999

CFX-4 Introductory Training (Dec 1999) 5 -3 CFX-4.3 V4.3.1H Constraints used to specify an interface connection between adjacent block faces with unequal areas. consistent mesh between two solids which do not meet at a whole face. Parent Face Child Face

Constraints There are 2 types of constraints in CFX Build Simple 2. Advanced Simple constraints-a single child face constrains the parent face. The child face must lie completely within the parent face Advanced constraints- One or more child faces constrain the parent face Edges on a child face may coincide with edges on the parent face 5-4 CFX-4 CFX4.3V4.3.1H Introductory Training(Dec 1999

CFX-4 Introductory Training (Dec 1999) 5 -4 CFX-4.3 V4.3.1H Constraints There are 2 types of constraints in CFX Build. 1. Simple 2. Advanced Simple constraints- A single child face constrains the parent face. The child face must lie completely within the parent face. Advanced constraints- One or more child faces constrain the parent face. Edges on a child face may coincide with edges on the parent face

AEATECHNOLoGY ENGINEERING SOFTWAR Creating Constraints ensure existence of aligned points specify corresponding Parent魂Ce parent/child origins Child Face define direction Parent origin points Child origin define direction ratios Parent First Direction determine if parent shape toggle is FIrst Direction RatIo necessary Second Direction Ratio d Use parent shape 5-5 CFX-4 CFX4.3V4.3.1H Introductory Training(Dec 1999

CFX-4 Introductory Training (Dec 1999) 5 -5 CFX-4.3 V4.3.1H Creating Constraints ensure existence of aligned points. specify corresponding parent/child origins. define direction points. define direction ratios. determine if parent￾shape toggle is necessary

AEATECHNOLoGY ENGINEERING SOFTWAR Parent/Child Points parent points any of four points 6 5 surrounding the parent face child points any of four points 8 surrounding the child face 5-6 CFX-4 CFX4.3V4.3.1H Introductory Training(Dec 1999

CFX-4 Introductory Training (Dec 1999) 5 -6 CFX-4.3 V4.3.1H Parent/Child Points parent points: - any of four points surrounding the parent face. child points - any of four points surrounding the child face. 1 2 3 4 6 5 7 8

Alignment of Points Ensure surface paths are aligned May need to rotate child surface Wrong Right 5-7 CFX-4 CFX4.3V4.3.1H Introductory Training(Dec 1999

CFX-4 Introductory Training (Dec 1999) 5 -7 CFX-4.3 V4.3.1H Alignment of Points Ensure surface paths are aligned. May need to rotate child surface. Wrong Right

Alignment of Directions occurs by specifying the points which represent the parent and child first direction parent and child directions must be similar S2 C2 E2 First Direction C1 S1 Second direction 5-8 CFX-4 CFX4.3V4.3.1H Introductory Training(Dec 1999

CFX-4 Introductory Training (Dec 1999) 5 -8 CFX-4.3 V4.3.1H Alignment of Directions occurs by specifying the points which represent the parent and child first direction. parent and child directions must be similar. S1 C1 E1 S2 C2 E2 First Direction Second Direction

AEATECHNOLoGY ENGINEERING SOFTWAR Direction ratios specify the ratios of the number of cells on either side of the child face S1 of cells upstream of child face in 1st direction E1# of cells downstream of child face in 1 st direction S2 #f of cells upstream of child face in 2nd direction E2 of cells downstream of child face in 2nd direction 1st direction ratio=R1= S1/S1+ E1) 2nd direction ratio=R2= S2/ (S2+E2) 5-9 CFX-4 CFX4.3V4.3.1H Introductory Training(Dec 1999

CFX-4 Introductory Training (Dec 1999) 5 -9 CFX-4.3 V4.3.1H Direction Ratios specify the ratios of the number of cells on either side of the child face - S1 # of cells upstream of child face in 1st direction - E1 # of cells downstream of child face in 1st direction - S2 # of cells upstream of child face in 2nd direction - E2 # of cells downstream of child face in 2nd direction. 1st direction ratio = R1 = S1/(S1 + E1). 2nd direction ratio = R2 = S2/(S2+E2)

AEATECHNOLOGY ENGINEERING SOFTWAR EXamples of Direction Ratios R1=2/(2+2)=0.5 R2=2/(2+2)=0.5 R1=2/(2+2)=0.5 R2=3/(3+1)=0.75 5-10 CFX-4 CFX4.3V4.3.1H Introductory Training(Dec 1999

CFX-4 Introductory Training (Dec 1999) 5 -10 CFX-4.3 V4.3.1H Examples of Direction Ratios R1 = 2/(2+2) = 0.5 R2 = 2/(2+2) = 0.5 R1 = 2/(2+2) = 0.5 R2 = 3/(3+1) = 0.75 2 1 2 1