Geometry Creation

4: CFD Tutorials 4.1: Geometry Creation

4.1.1: 2D Pipe Junction Overview

We are going to create geometry for a two-dimensional pipe junction as shown in the figure below.

Figure4-1 2D Pipe Junction with Dimensions

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Geometry Creation

a) Summary of steps

Geometry Menu

Creating the points using Explicit Coordinates

Creating the points using Curve-Curve Intersection

Creating the curves using From Points

Creating the curves using Arc through 3 points

Segmentation of curve using Segment Curve

Deleting unused entities

Creating Material Point using Mid Point

File Menu

Saving the geometry

b) Point Creation

Note:

1. Settings > Selection >Auto pick mode should be turned OFF.

2. Settings>Geometry Options>Name new geometry must be turned ON.

3. Settings>Geometry Options>Inherit Part name>Create new must be toggled ON

4. In case UNDO is used after creation of any point, and then a new point is created, the new point will have the next name in series. For example, if Point05 is created and Undo is used, then the next point created will be named Point06.

Select Geometry Create Point > Explicit Coordinates > Select Create 1 Point. Input the Part name POINTS and Name as POINT 00.Assign coordinates (0 0 0) shown below. Press Apply to create a point.

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Geometry Creation

Figure 4-2 Point creation window

Switch ON the Geometry > Points in the left side Display Tree window. To see the names of the points, use the right mouse button and select Points > Show Point Names in the Display Tree window. Select Fit Window from the main menu. Use the right mouse button to zoom out if needed. The created point name would be shown as POINT00.

Now enter the coordinates as shown below, and press Apply after each one. You will see the names automatically change to the ones shown below:

POINT01 (32, 0, 0)

POINT02 (0, 16, 0)

POINT03 (32, 16, 0)

POINT04 (48, 32, 0)

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POINT05 (48, 64, 0)

POINT06 (64, 32, 0)

POINT07 (64, 64, 0)

POINT08 (50, -5, 0)

POINT09 (54, -5, 0)

POINT10 (16, 32, 0)

POINT11 (0, 32, 0)

POINT12 (50, 16, 0)

POINT13 (54, 16, 0)

Figure 4-3 Points created thus far

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Geometry Creation

Press Dismiss to close the window. Go to View > Front. The Display window should now show the points as seen in the figure above. The location of points can also be checked by following way Go to Utility

Icons > Click on the inverted arrow below Measure distance icon

>Last option is Find Location Select any point on screen. The Co-Ordinates of the point will be shown on screen as well as will be visible in the Message Window.

c) Line Creation

reate odify Curve

Geometry > C /M > From Points: Select the From

oints option P .

Figure 4-4 : From points window

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Geometry Creation

To select Points, click on (select point icon) and then select POINT00 and POINT01 with the left mouse button. Press the middle mouse button to accept the points. The point names will appear in the selection window. Enter the Part as CURVES, and the Name as CURVE00. Switch ON Geometry > Curves in the Display Tree if they are switched off. To see the names of the curves, use the right mouse button and select Curves > Show Curve Names in the Display Tree. Use the right mouse button to zoom out if needed. The created line name would be shown as CURVE00.

imilarly, select the following points, pressing S middle mouse button each y default the names of each ft:

T012 URVE08 from POINT09 and POINT013

he window.

eometry > Create/Modify Curves

time. Without changing the Name entry, bnew curve would appear as shown on the le CURVE01 from POINT00 and POINT02 CURVE02 from POINT02 and POINT03 CURVE03 from POINT04 and POINT05 CURVE04 from POINT05 and POINT07 CURVE05 from POINT06 and POINT07

T09 CURVE06 from POINT08 and POINURVE07 from POINT08 and POINC

CPress Dismiss to close t

d) Arc Creation

G > Select Arc Through 3 points

to open the window here.

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Geometry Creation

Figure 4-5 Arc from 3 points window

To select Points click on (select point icon), and select the points POINT04, POINT03 and POINT10 with the left mouse button. Press the middle mouse button to accept the point. Click on the drop down menu next to the Part field to select an existing Part Click on CURVES to select this Part in the window. Enter the Name as CURVE09 and press Apply to create the arc. Similarly, make another arc named CURVE10 out of points POINT06, POINT01, and POINT11. Press Dismiss to close this window. The eometry after creating the two arcs is shown here. g

Figure 4-6 Geometry after arc creation

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Geometry Creation

e) Curve-Curve Intersection

Geometry >Create Point > Select Curve-Curve Intersection thewindow opens as shown below. Select the Part name POINTS. Select CURVE10 and CURVE07 with the left mouse button. Press the middlemouse button to accept the selection. Give Gap a Tolerance of 0.1 and press Apply. This will create the intersection point called POINT14. Repeat the procedure for curves CURVE10 and CURVE08 and press

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Apply without changing the name in the Name window to get the intersection point POINT15. Press Dismiss to close the Create Point window.

Figure 4-7 Selection window of Curve-Curve Intersection

f) Segmentation of Curves at existing points

Geometry > Create/Modify Curve > Select Segment curve . In the dropdown, Segment by Point should be selected. Select the cur

selection icon

ve

and select CURVE10 with the left mouse button.

Now select the point selection icon and select POINT01 with the left mouse button and then press the middle mouse button to accept the point. Select the Part CURVES .After pressing Apply, the CURVE10 segments into two curves, CURVE10 and CURVE11.

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er segmenting two Curves at a particular Point the Curves name may be ifferent but user can refer to the figure below and select the Curves to be eleted.

Figure 4-8 Geometry after curve segmentations

Similarly segment CURVE09 at POINT03 to get CURVE09 and CURVE12. Segment CURVE07 at POINT14 to get CURVE07 and CURVE13. Segment CURVE08 at POINT15 to get CURVE08 and CURVE14. The geometry after segmenting the curve is shown below. Note: Aftdd

Geometry Creation

g) Deletion of unused entities

Geometry > Delete Curve - This will open the Delete Curve window.

Select the curve selection icon and select CURVE11, CURVE12, CURVE13 and CURVE14. Press the middle mouse button to complete the selection. Press Apply to delete these curves.

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Geometry >Delete Points This will open the Delete Points window.

Select the point selection icon and select POINT10, POINT11, POINT12 and POINT13. Press the middle mouse button to complete selection, and press Apply to delete these points.

h) Creating the Material point

Geometry > Create Body > Material Point > Centroid of 2

points: Select the location selection icon and click close to POINT01 and POINT03 with the left mouse button. Press the middle mouse button to complete the selection. Give the Part name BODY, and press Apply to create the material point. Switch on Bodies in the left side Display Tree window to see the body. The Geometry after creating material point is shown below. Figure 4-9 Final Geometry

Geometry Creation

i) Saving Geometry

File > Geometry > Save Geometry As: Enter the file name as Geo_2DPipe.tin and press Save to save the geometry file

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4.1.2: 3D Pipe JunctionOverview

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te geometry for a three-dimensional pipe junction as hown here.

4-10

We are going to creas FigureThe 3D Pipe Junction geometry with dimensions

a) Summary of steps Create points, then curCreate surfaces from c

ves from points urves

Geometry Creation

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Curves from Surfaces-Segment surface with tionDelete unused segmented surfacesCreate material point

b) Point Creatio

Note: 1. Settings > Selection >Auto pick mode should be turned OFF.

must be ggled ON

. In case UNDO is used after creation of any point, and then a new point e next name in series. For example, if

d and Undo is used, then the next point created will be named Point06.

Geometry >Create Poin

Surface Intersection the intersec curve

n

2. Settings>Geometry Options>Name new geometry must be turned ON. 3. Settings>Geometry Options>Inherit Part name>Create new to4is created, the new point will have thPoint05 is create

t > Explicit Coordinates - Select Create 1 Point. Input the Part name POINTS, and Name as POINT00. Enter the co-ordinates (0 0 0) and Press Apply to create a point. Switch on the Geometry > Points in the left side Display Tree window. To see the names of the points, use the right mouse button and select Points> Show Point names in the Display Tree window. Select Fit Window from the main menu. Use the right mouse button to zoom out if needed. The created point name will be shown as POINT00. Now, create the rest of the points listed below by just entering the locations. The names continue on from POINT00, so they will automatically change as shown below:

POINT02 (0, 0, -50) OINT03 (0, 50, 0)

POINT04 (150, 0, 0) POINT05 (150, 0, 50)

POINT01 (0, 0, 50)

P

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POINT06 (150, 0, -50)

INT11 (150, 100, 20) POINT12 (150, 100, -20)

ld the Isometric view.

POINT07 (150, 50, 0) POINT08 (150, 0, 20) POINT09 (150, 0, -20) POINT10 (130, 0, 0) PO

POINT13 (130, 100, 0)

Press Dismiss to close the Explicit Location window. The points shouappear as shown below when oriented in Figure 4-11

oints createdP

c) Arc Creation

Geometry Creation

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Geometry > Create/Modify Curve > Select Arc through 3 points:

to open command window. Type the Part name as CURVES. Enter

the Name as C on URVE00. Select the location selection ic and select points POINT01, POINT03 . Press Apply to create the arc. Switch ON the e dow. To see the names of the c r ct Curves > Show Curve names in the Display Tree window. The newly created

T05, POINT07 and POINT06 and enter the name as URVE01. Press Apply to create the arc.

just selecting the points as specified below and pressing Apply each time. The curve names will be generated as shown below: CURVE02: POINT08, POINT10 and POINT09 CURVE03: POINT11, POINT13 and POINT12 Press Dismiss to close the window.

d) Line Creation

Geometry > Create/Modify Curves

and POINT02 with the left mouse button

Curves in th left side Display Tree winurves, use the ight mouse button and sele

curves name will display as CURVE00. Similarly, select POINC Now, make two more arcs by

> Select From Points: Press

the location selection icon , select the Points POINT01 and POINT02 with the left mouse button, and press the middle mouse button to complete the selection. Enter the Part name CURVES and Name CURVE04.

Geometry Creation

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Similarly, create six more lines using the points listed below. For each curve the curve names will adjust consecutively according to previous curve:

CURVE05: POINT01 and POINT05 CURVE06: POINT02 and POINT06 CURVE07: POINT05 and POINT06 CURVE08: POINT08 and POINT11 CURVE09: POINT09 and POINT12 CURVE10: POINT11 and POINT12

Press Dismiss to close the window. The Geometry after curve creation is shown below. Switch OFF the Points in the Display Tree window to avoid clutter on the screen. Figure 4-12 Geometry after line creation

Geometry Creation

e) Surface Creation

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Geometry >Create/Modify Surface > Select Simple Surface on to open the window shown. ic

Geometry Creation

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igure 4-13 F

Surface creation from curve

Select the option From 2-4 curves. Press the curve selection icon and select the curves CURVE00 and CURVE01 with the left mouse button. Press the middle mouse button to complete the selection. Enter a Tolerance as 0.01. Enter the Part name CYL1 and Name CYLIN01. Press Apply to create the surface. Note: Pressing the right mouse button while in selection mode will cancel each previous selection.

Switch ON the surfaces from the left side Display Tree window. To see the names of the surfaces, using the right mouse button, select Surface > Show Surface names in the Display Tree window. Use the right mouse

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button to zoom out if needed. The newly created surface name would display as CYLIN01. Similarly, create the other surfaces as follows, entering the part names and names each time:

PART NAME SELECTED CURVES

INL INL01 CURVE00, CURVE04

CYL2 CYLIN02 CURVE02, CURVE03

OUT OUT01 CURVE03, CURVE10

SYM SYM01 CURVE04, CURVE07

SYM SYM02 CURVE01, CURVE07

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ree

f) Surface-Surface Intersection

Geometry >Create/Modify Curves

Press Dismiss to close the window. The Geometry after surface creation isshown in the figure above. Switch OFF the Curves from the Display Twindow to avoid clutter on the screen.

> Surface-Surface

Intersection >Select first option Surfaces. Select the surface

re 4-14 try after Surface creation

FiguGeome

Geometry Creation

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selection icon to select surfaces CYLIN01 and CYLIN02 with the left mouse button, pressing the middle mouse button to complete the selection e e. Check that the part name selected is CURVES. Press Apply to create the intersection curve.

g) ntation of Surface

Geometry > Create/Modify Surface

ach tim

Segme

> Segment/Trim surface : Choose the Method by Curves, which is the default. Press the surface

selection icon and select the surface CYLIN01 using the left mouse iddle mouse button to complete the selection. Press

the curve selection icon

button and press the m

and using the left mouse button, select the intersection curve that was created in the previous step. Press the middle mouse button to complete the selection. Check that the part name selected is CYL01. Press Apply to segment the surface CYLIN01 into two parts.

imilarly, segment the surface CYLIN02 with the same intersection curve. the two previous curves have been split into two, then select both

Deleting unused entities

SIfcurves. Check that the part name selected while segmenting is CYL02.

Geometry > Delete Surface this opens the Delete Surface window, Select the surface CYL1.1 and CYL2.1.cut.0 with the left mouse button.

ress the middle mouse button to compPto delete th

lete the selection and press Apply ese surfaces. The surfaces are marked in the figure below.

Figure 4-15 Surfaces to be deleted

Geometry Creation

Note: The curves and points will need to be deleted, so the next step,

uild topology, will not segment the surfaces where the curves span them.

eometry > Delete Curv

b

e G to open the Delete Curves window. . Press a on the keyboard to select all

Geometry > Delete Poin

Check ON Delete permanentlycurves, and press Apply to delete.

t to open the Delete Point window. Check ON Delete permanently. Press a on the keyboard to select all points, and press Apply to delete them. Settings > Geometry Options > Inherit part name > Inherit should be Toggled ON. This will ensure that all the points and curves extracted during Build Topology operation will be moved to their respective parts.

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h) Build topology

Geometry > Repair Geometry > Build Diagnostic Topology This will extract all the curves from the surfaces, and the points from the curves. But the new curves will only span the boundary of the new surfaces after segmenting and deleting. The tolerance should be 0.1, and Filter points and Filter curves should be turned off. Press Apply.

i) Surface creation First, make sure Curves are ON in the Display Tree. Again we have to change Settings > Geometry Options > Inherit part name > to Create New.

Now select Geometry > Create/Modify Surface : Select Simple surface

to open the Create/Modify Surface window. Select Method-From Curves. Select the curves shown below with the left mouse button and press the middle mouse button to complete the selection. Make sure the Part name is SYM and the Name is SYM03. Press Apply to create the surface.

ress Dismiss to close the window. P Figure 4-16 Curves for surface

Geometry Creation

j) Creating the Material point

Geometry > Create Body >Material Point >Centroid of 2 points: Select

(Create Body). Type BODY for the new Part name. Select any two locations on any surfaces, curves or points so that the midpoint will be within the pipe junction. Press the middle mouse button to accept, then press Apply. The final geometry is shown below.

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Final Geometry Figure 4-17

k) Saving Geometry

eometry As: Enter the file name as etry.

File > Geometry > Save GDP pe.tin and press SGeo_3 i ave to save the geom

Geometry Creation

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4.1.3: Sphere Cube

iew Overv

We will create geometry for a sphere cube as shown below. Figure 4-18 The sphere cube with dimensions

a) Summary of steps Create Cube by StandCreate Hemisphere (SCreate points at Param ter along curve Create arcs to use to create the symmetry surfaces

ard Shapes urface of Revolution) e

Geometry Creation

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ting the Geometry

1 Settings > Selection >Auto pick mode should be turned OFF. 2 Settings >Geometry Options > Name new geometry must be turned ON. 3 In case UNDO is used after creation of any point, and then a new point is created, the new point will have the next name in series. For example, if Point05 is created and Undo is used, then the next point created will be named Point06. 4 Settings>Geometry Options>Inherit Part name>Create New must be toggled ON.

c) Point Creation

Go to Geometry >Create Point > Explicit Coordinates

b) Genera

Note:

. Give the Part name POINTS, and the Name POINT00. Enter the co-ordinates (5, -

e

s in

10, 0) and press Apply to create the point.

Switch on the Points in the Display Tree window. To see the names of thpoints, use the right mouse button to select Points > Show Point name

the Display Tree window. Select Fit Window from the main menu. se the right mouse button to zoom out if needed. The newly createU d point

ional lly adjust as

POINT01 (-10,5, 0) POINT02 (20, 5, 0) POINT03 (5, 20, 0)

name would be displayed as POINT00.

imilarly, enter the coordinate as below and create 3 more additSpoints at the following locations. The names will automaticashown below:

Geometry Creation

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window. The Geometry after point creation is

Press Dismiss to close theshown in below.

Figure 4-19 Points created so far

d) Arc Creation

Geometry > Create/Modify Curve > Arc through 3 points Select POINT01, POINT00 and POINT02 with the left mouse button, and press the middle mouse button to complete selection. Enter the Part as CURVES and Name as CURVE00. Press Apply to create the arc. Similarly, create another arc called CURVE01 from points POINT01,POINT03, and POINT02. Press Dismiss to close the window. Note: Turn on Curves in the Display tree to see the curves.

Geometry Creation

e) Cube Creation

Go to Geometry > Create/Modify Surface > Standard Shapes > Box

icon . Change the Part name to CUBE, and the Name to CUBE.1.

should

igure

e

Enter the XYZ size as 10 10 5. These values will be in X, Y and Z directions as 10, 10 and 5 respectively. Type 0 0 0 for the Box Origin coordinates. Press Apply to create the cube. The geometry so farlook like the figure below. F4-20: Geomso far

try

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ich curve to select in this step.

eometry > Create/Modify Surface

f) Hemisphere Creation Note: Turn ON Geometry > Curves > Show Curve Names in the Display Tree, to see wh

> Surface of Revolution . GChange the Part to SPHERE0 and the End angle as 180

, Name to SPHERE01. Enter the Start angle . Select Axis Points as POINT01 and

POINT02. Select curves as CURVE00 and press Apply to create the hemisphere. Figure4-21: Surfacrevolution window

e of

Geometry Creation

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isplay Tree window. To see the names of lect Surfaces > Show Surface Names in the Display Tree

window using the right mouse button. The geometry should resemble the figure below. Figure 4-22 Geometry after revolution

Switch ON the Surfaces in the Dthe surfaces, se

g) Point Creation

Geometry >Create Point > Parameter along a Curve to open the indow as seen below. For a clearer view, the user can turn OFF Surfaces

kwin the Display Tree, and ma e sure that Curves and Points are ON.

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igure 4-23: Point Parameter on urve window

F

c

Turn off the part SPHERE and Turn ON Points > Show Point Names in

ly ly

NT06. Then change the parameter to 0.25, and press

tion window.

Geometry > Delete Curve

the Display Tree to be able to see the curve names better. Select the Part as POINTS. And enter the Name as POINT04. Then select the curve, CURVE00. Enter Curve Parameter 0.25 and press Appto create POINT04. Then change the parameter to 0.75, and press Appagain to create POINT05. Next, select the curve, CURVE01. With the parameter left at 0.75, press

pply to create POIAApply again to create POINT07. Press Dismiss to close the selec

- Toggle ON Delete permanently. Select the curves, CURVE00 and CURVE01, and press Apply.

Geometry Creation

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h) Arc Creation

Geometry > Create/Modify Curve > Arc through 3 points: . Make sure Point Names are being displayed by right clicking in the Display Tree on Points > Show Point Names. Select the points, POINT05, POINT02, and POINT06. Enter the Part as CURVES and the Name as CURVE00. Press Apply to create the arc. Similarly create three other arcs by using the following points: CURVE01: POINT06, POINT03 and POINT07 CURVE02: POINT07, POINT01 and POINT04 CURVE03: POINT04, POINT00 and POINT05

ce Creation

Geometry >Create/Modify Surface

Press Dismiss to close the window.

i) Surfa

> Simple Surface > Select From Curves option to open the Select Curves window. Turn OFF the Points (Geometry) for a better view. Also turn OFF the curve names : Curves > Show Curve Names for a better view. Select the two curves shown in black below, and press the middle mouse button to complete the selection. Assign the Part as SYM and Name as SYM.1. Press Apply to create the surface. Press Dismiss to close the window. Figure 4-24 Curves for Surface

Geometry Creation

Similarly, create the other three surfaces around the cube. The result is shown below. Figure 4-25 Symmetry Surfaces

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Geometry Creation

j) Deleting unused entities

Geometry > Delete Surface Select the surface shown in black in the figure below with the left mouse button. If there is too much clutter, the user can switch OFF all other Parts except CUBE. Press the middlemouse button to complete the selection, and press Apply to delete the surface.

Figure 4-26 Surface to delete

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k) Creating the material point

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Geometry > Create Body >Material Point >Centroid of 2 Point - ssign the name BODY to a new Part. Select one of the corners of the UBE that do not lie inside the flat plane of the SYM surfaces. Select the

second point on the surface of the sphere. Then press Apply. Switch ON Bodies in the Display Tree window to see the material point. It should appear inside the hemisphere of the SPHERE surface but outside of the CUBE. The final geometry is shown below.

Figure 4-27 Final Geometry

AC

Geometry Creation

l) Saving Geometry

File > Geometry > Save Geometry As: Enter the file name eo_SphereCube.tin and press Save to save the geometry. G

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Geometry Creation

4.1.4: Pipe Blade Overview

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de with dimensions

We are going to create the geometry for a pipe blade. Figure 4-28 : The Pipe Bla

a) Summary of

Geometry Menu

Create points Create arcs for the blaCreate Cylinder from Standard Shapes

on curves. ote: Settings > Selection >Auto pick mode should be turned OFF.

ame new geometry must be turned ON.

steps

de

Create surfaces for the blade and inlets and outlets. Intersect surfaces, and trim surfaces by those intersectiN12 Settings>Geometry Options>N

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3 In case UNDO is used after creation of any point, and then a new point is created, the new point will have the next name in series. For example, if Point05 is created and Undo is used, then the next point created will be named Point06. 4 Settings>Geometry Options>Inherit Part name>Inherited must be toggled ON.

b) Point Creation

Geometry >Create Point > Explicit Coordinates . Assign the Part name POINTS, and the Name POINT00. Enter the co-ordinates (0, 2, 8), and press Apply to create the point. Switch on the Points in the Display Tree window. To see the names of the points, use the right mouse button and select Points > Show Point names

in the Display Tree window. Select Fit Window from main menu. Use the right mouse button to zoom out if needed. The newly created point name would be displayed as POINT00. Sim eate another point by entering the coordinate. The names will

he names shown below: POINT01 (0,2, 12)

POINT05 (0, -2, 12)

o close the window. The points should appear as shown in e figure below when viewed in the Isometric view:

reated so far

ilarly, crautomatically adjust to t

POINT02 (0.3, 2, 10) POINT03 (-0.3, 2, 10) POINT04 (0, -2, 8)

POINT06 (0.3, -2, 10) POINT07 (-0.3, -2, 10)

Press Dismiss tth Figure 4-29-Points c

Geometry Creation

c) Arc Creation

Geometry > Create/Modify Curve > Arc through 3 points Enter the Part CURVES and the name as CURVE00. Select POINT00, POINT02 and POINT01. Press Apply to create the arc. Switch on the Curves in the Display Tree window. To see the names of the curves, right mouse click on Curves > Show Curve Names in the

ewly created curve name would be displayed s CURVE00.

Display Tree window. The na

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CURVE01: POINT00, POINT03 and POINT01 CURVE02: POINT04, POINT06 and POINT05

POINT04, POINT07 and POINT05

Press Dismiss to close the window. To reduce clutter on the screen switch off the Points from the Display Tree window. The geometry after arc creation is shown below.

d) Cylinder Creation

Figure 4-30 Geometry After Arc Creation

Similarly, create several more arcs using the following points. The curvenames will automatically follow the first curve name to adjust to the names seen below:

CURVE03:

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Geometry > Create/Modify Surface > Standard Shapes >

Cylinder: Select (Cylinder) to open the Create Std Geometry window as shown below. Enter the Part name CYL and Name CYLIN01Enter a Radius1 =2, Radius2 =2. For the Two axis Points, enter {0 0 0{0 0 20}. Press Apply to create the cylinder.

. }

ress Dismiss to close the window. P

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reation Figure 4-31 Cylinder C

e) Surface Creation

Geometry >Create/Modify Surface >Simple Surface >Method- From 2-4 Curves> Enter the Part name as BLADE and the Name as BLADE00.Enter the tolerance as 0.1.Select CURVE00 and CURVE02 with the left mouse button. Press the middle mouse button to complete selection, and press Apply to create the surface.

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Similarly, create the other blade surface BLADE01 by selecting CURVE01 and CURVE03. To create the OUTLET surface, Go to the Display Tree and Right Click on Parts. It will open a window as shown below. Figure 4-32 Creating new part

Select option Create Part .This will open another window as shown below. Rename default part name PART.1 as OUTLET.

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Figure 4-33 Creating Outlet

Select the Surfaces of Cylinder from Screen .Apply. Thus part OUTLET is created. Dismiss. Figure 4-34-Creating Surface Outlet

Geometry Creation

Sim to OUTLET and rename it to INLET. Switch ON the Surfaces in the Display Tree window. To see the names of the on and select Surface > Show Surface Names in the Display Tree window. The geometry after surface creation is shown below. Press Dismiss to close the window. Figure 4-35 Geometry After Surface Creation

ilarly select the surface opposite

surfaces, use the right mouse butt

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Geometry Creation

f) Surface-Surface Intersection

Geometry >Create/Modify Curve > Surfaces-Surface Inter ionsect

. Choose the B-Spline option. Select the two surfaces shown in thefigure below. Select the BLADE00 surface for Set1 Surfaces and the CLYIN01 surface for Set2 Surfaces, pressing the middle mouse button each tim

e. Select part name as CURVES. Press Apply. Repeat this for the ther side of the blade.

Figure 4-36 First intersection curve

o

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Geometry Creation

The detailed view is shown below.

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Figure4-37DetailedView

g) Build topology

> Build Diagnostic Topology . Geometry > Repair GeometryThis will extract all the curves from the surfaces, and the points from the curves, and delete any duplicates. It will also automatically segment the surfaces by the previously created intersection curves. Set the tolerance to 0.002, and Filter points and Filter curves should be turned off. Press Apply.

h) Deleting unused entities

Geometry > Delete Surface . Delete the surfaces shown in the figure below. Repeat this for the other side of the tube.

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Figure 4-38 Surfaces to delete

i) Build topology

eometry > Repair Geometry

G > Build Diagnostic Topology B

Geometry > Create Body

uild topology once more, with same tolerance of 0.002.

j) Creating the material point

> Material Point > Centroid of 2 points:

(Create Body) to open thSelect e window. Enter a new Part name f FLUID and select one location on the blade and one location on the

INLET or OUTLET so that the midpoint will be inside the tube but outside the blade. Press the middle mouse button to complete the selection process. Press Apply to create the material point. The final geometry is below .

Figure 4-39 Final Geometry

o

Geometry Creation

k) Saving geometry

File > Geometry > Save Geometry As: Enter the file name as Geo_PipeBlade.tin and press Save to save the geometry file.

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4.1.5: Geometry Simplification using Shrinkwrap

Im e STL file

losing the Geometry Creating Facets Diagnostics Creation of Geometry entities Splitting of Sphere Build topology

b) Starting the project

The input files for this tutorial can be found in the Ansys installation directory, under ../v110/docu/Tutorials/CFD_Tutorial_Files/Geometry Shrinkwrap. Copy the files to your working directory and Select File > Import Geometry > STL > Select eng_comp2.stl file as shown in the figure below and press Apply.

Figure 4-40 Import Geometry from STL

a) Summary of steps

porting thCreating a Shrinkwrap C

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Geometry gets loaded on the screen. Right mouse select Geometry > Surfaces in the Display tree and select Show Full to see the full triangulation of the surfaces.

Figure 4-41 Geometry after Loading

c) Geometry Simplification by Creating a Shrinkwrap

Go to Settings>Geometry Option > Inherit Part Name and toggle ON option Inherited.

Select Create/Modify Surfaces >Geometry Simplification > Cartesian Shrinkwrap This will open up the window shown below.

Figure 4-42 Cartesian Shrinkwrap

Geometry Creation

Enter Max Cell Size as 4.12, Number of smooth iterations as 5, Surface projection factor as 0.1, Part for envelope as Inherited. Turn ON Active Parts Only tab and Apply. A Shrinkwrap will be created s shown and will be listed in the Mesh Display Tree. a

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Figure 4-43 After creating Shrinkwrap

d) Closing the geometry- Select File>Geometry>Close Geometry. This will close all the geometry entities and only Mesh will remain on the Screen.

e) Creating Facets

Select Edit in Main menu and then select Mesh ->Facets.

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esh to Facets Figure 4-44 Converting M

A window will pop up as shown below.

Figure 4-45 Sharp Features

Select NO to build sharp features. Another window will open as below

Geometry Creation

Select Yes. The Shrinkwrap Me is c

sh reated and listed in the Mesh Display Tree.

f) Checking the Mesh

Select Check Mesh . The Check Mesh window will open as shown below. Toggle ON Penetrating Elements in Error List. Press Apply.

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Geometry Creation

Figure 4-46 Check Mesh

There should be no errors in the mesh.

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g) Checking Quality of Mesh We need to check the mesh for any errors or problems that may cause

problems for analysis. Select Display Mesh Quality . Keep the defasettings and APPLY.

ult

h) Smooth Elements Globally

e >

mooth Mesh Globally

Several elements have a lower quality so we need to smooth somelements so as to improve the Quality of mesh. Select Edit Mesh

. S

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lly Figure 4-47 Smooth elements globa

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worea right

File

hing

lock

igure 4-48

Chr

ICEcom

Change the Up to value to 0.4 and Toggle ON the options "Not just rst 1%" and "Allow node merging" and press Apply. The Quality ched can be seen in a Histogram that will appear on the lower

corner of the screen.

i) Saving geometry > Geometry >Save Project As: Enter the project name as

Shinkwrap and press Save to save the geometry file

4.2: Hexa Mes

ANSYS ICEM CFD is a 3-D object-based, semi-automatic, multi-bstructured and unstructured, surface and volume mesher.

FThis mesh for the Mercedes SLK (model courtesy of Daimler-

ysler) was generated with

M CFD Hexa bining the

exterior and cabin flow

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ANmesh generation. The block topology model is generated directly upon the

easy-to-use interface, those ugh

autoRecAN eshes for

s in a fracThe uring the mesh

geo may be further refined through the splitting

surf ortant CA

odels, topology transformations such as translate, rotate, irror, scaling and translate and rotate are available. The simplified block

neration and manipulation of the block

gen n diff

e same material may also be associated to specific CAD surfaces for definition of internal walls. In general, there is no need to

any individual face associations to underlying CAD geometry, reducing time for mesh generation.

-grids: For complex geometry, ANSYS ICEM CFD Blocking automatically generates body-fitted internal and external O-grids for creating good quality meshes.

4.2.1: Introduction SYS ICEM CFD Blocking represents a new approach to hexahedral

underlying CAD geometry. Within an operations most often performed by experts are readily accessible thro

mated features. ognized as the fastest hexahedral mesh generation tool in the market, SYS ICEM CFD allows users to generate high-quality m

aerospace, automotive, computer and chemical industry applicationtion of the time required for traditional tools. user has access to two categories of entities d

generation process in ANSYS ICEM CFD: block topology and geometry. After interactively creating a 3-D block topology model equivalent to the

metry, the block topologyof edges, faces and blocks. In addition, there are tools for moving the block vertices individually or in groups onto associated curves or CAD

aces. The user may also associate specific block edges with impD curves to capture important geometric features in the mesh.

For symmetric mmtopology concept allows rapid gestructure and ultimately, rapid generation of the hexahedral mesh. ANSYS ICEM CFD Blocking provides a projection-based mesh

eration environment where, by default, all block faces betweeerent materials are projected to the closest CAD surfaces. Block faces

within thto allow performgreatly

a) Features of ANSYS ICEM CFD Blocking

O

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offer unlimited

Me ith may be displayed to highlight the block

he individual blocks need to be adjusted.

in

Rep bles parametric block topology anges in geometry.

Lin eforming

djustability: Options to generate 3-D surface meshes from the 3-D volume mesh and 2-D to 3-D block topology transformation.

blocks creation for mapped surface

Firs

Intetop down approach else create blocks and extrude blocks: bottom up

proach. Blocks are at first created independently of the geometry.

Edge-Meshing Parameters: Hexas edge-meshing parameters flexibility in applying user specified bunching requirements.

sh Quality Checking: With a set of tools for mesh quality checking, cells wundesirable skewness or anglestopology region where t

Mesh Refinement/Coarsening: Refinement or coarsening of the mesh may bespecified for any block region to allow a finer or coarser mesh definitionareas of high or low gradients, respectively.

lay Option: Replay file functionality enageneration linked to parametric ch

Symmetry: Can be used in analyzing rotating machinery applications. For example, Hexa allows the user to take advantage of symmetry in meshing a section of the rotating machinery thereby minimizing the model size.

k Shape: This allows the user to link the edge shape to an existing dedge. This gives better control over the grid specifically in the case of parametric studies.

A

2D Surface Meshing: Automatic 2D meshing.

b) Mesh Generation with Blocking Overall Process

t, create or import geometry using any of the direct, indirect or faceted data interfaces.

ractively split blocks, discard unused blocks to capture underlying shape:

ap

Associate edges to curves to capture hard features. Move vertices to position block corners on geometry.

Assign mesh sizes such as maximum element size, initial element height and expansion ratio to surfaces and/or curves. Assign edge meshing parameters for better control of node distributions.

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rite Output files to the desired solvers.

can generate the mesh with various schemes such as full face projection int or no projection at all.

In the case of no projection, the mesh will be generated on the faces of the block model and may be used to quickly determine whether the current blocking strategy is adequate or not.

Afterwards, a block file can be used as a template for similar geometries, such as parametric design changes. Necessary alterations can either be done manually, automatically update projection or running a replay script; depending on the nature of the change.

c) The Blocking Database

ill have an extthe information necessary for defining and com uctured mesh including block definitions, part associations, and mesh size parameters. Block definitions include the following block topology types:

Vertices

Edges

Faces

Blocks

All of the block entities are defined by I, J, K index.

Automatically generate mesh. Boundary nodes will project on to geometry, volumes are interpolated. Check mesh quality to ensure that specified mesh quality criteria are met.

W

If necessary, the user may always return to previous steps to manipulate theblocking if the mesh does not meet the desired quality or if the mesh does notcapture certain geometry features. The blocking may be saved at any time, thus allowing the user to return to previous block topologies.

t any point in this process, the userAprojectionprojection

, edge projection, po

T e blocking database (block file) wh ension of *.blk. It contains all puting the block str

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The block or unstructured files for

Uns

he unstructured mesh output option will produce a single mesh output file mmon nodes on the block interfaces are merged,

dent of the number of blocks in the model. Unstructured elements

n node numbers.

locks upon output can be reduced by an automatic internal

ere are some of the most often used functions within the Blocking menu:

s

he most common way of

ross all visible

d) Unstructured and Multi-block Structured Meshes

computed mesh stored internally within Blocking is termed Pre-Mesh.Pre-Mesh is then converted to either multi-eventual output to the solvers.

tructured Mesh Output

T(*.uns) where all coindepenare defined by node number definition.

Multi-Block Structured Mesh Output

The multi-block structured mesh output option will produce a mesh output file for every block in the topology model. For example, if the block model has55 blocks, there will be 55 output files created in the output directory. Elements are defined by I, J, K indices rather tha

The number of bmerge of blocks (Output Blocks).

e) Main Blocking Functions

H

Initialize blockThis is under Blocking > Create Block. First, a block is defined that

encompasses the entire or selected portions of the geometry. This block iassociated to a part (SOLID is the default part name). This volume part should be different than any part containing geometry. This initial block is then modified by splitting, discarding unused blocks, and creating O-grids.

SplitThis option is under Blocking > Split Block. Tcreating blocks is to split existing blocks. The Split function, which divides the selected block interactively, may propagate acblocks, selected blocks or selected faces. An edge is selected and the split (new) edges will propagate perpendicular to the selected edge. Blocks

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new , J, K or radial (if splitting an o-grid) index.

may be visually blanked/unblanked by using the Index control which toggles the blocks in I, J, K or radial (if o-grids exist) directions. Any split will create a new I O-grid Creation Subdivides selected blocks into a configuration of one central block surrounded by radial blocks. Accessed through Blocking > Split Block > O-grid Block. Recommended for cylindrical type geometries to avoid badinternal angles at block corners. Figure 4-49 OGrid Block

The initial block

The initial block with an O grid The initial block with an O grid to

include a face

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re or after O-grid creation. The scale factor (Offset) is e ratio of the radial edge to the shortest edge of the initial block. The larger

dial edge and the smaller the central block.

metric entities. Most of to curves. This will make sure hard

s to ,

ove vertex nodes to the nearest point in the normal geometry. Its always best to manually position the node

epending on their constraint to the ertex movement depends on this constraint:

st CAD surface during pre-mesh computation. an only be moved on active surfaces.

rtices: Associated to curves. The vertices can only be s to which they have been projected.

Red Vertices: Vertices projected to prescribed points. They are fixed and cannot be moved unless projection type is changed.

Adding faces will create an O-grid that passes through the selected block facescreating a C-grid configuration. The last diagram shows the result of adding a face on the left side of the block.

O-grids can be scaled befoththe factor, the longer the ra

Associate

he next step is to associate block entities to geoTthe time, this means associate edgesfeatures are captured. Other options are to associate vertices to pointcapture sharp corners and faces to surfaces if the default face projectionwhere nodes are projected to the nearest point in the normal direction tothe nearest surface, fails to give proper results. Move vertices Vertices are typically moved on to the geometry. Computation will utomatically ma

direction on the on to the geometry rather than leave it up to the default projection. Color Coding

ll vertices and edges are color coded dAgeometry. VWhite Edges and Vertices: These edges are either on the boundary or between two material volumes. The edge and the associated vertices will e projected to the closeb

White vertices cBlue (Cyan) Edges and Vertices: Internal, between blocks of the same volume. Blue vertices can be moved by selecting the edge just before it nd can be dragged along that edge direction. a

Green Edges and Vemoved on the curve

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hen

sh Parameters

Pre-Mesh in the Display Tree will then prompt e user to (re)compute the pre-mesh.

ine-tune the node distributions within Pre-Mesh

rescribed on individual edges. These distributions can be copied to el edges down and upstream of the selected edge.

e pre-mesh to unstructured or multi-block, the quality ould be checked. Blocking > Pre-Mesh Quality will create a histogram

the same manner as for Edit Mesh > e

ed by Blocking > Delete Block. By hese deleted blocks are actually moved to the VORFN part.

BlocksRFN part is a default part that is automatically created when is first initialized. The initial block will actually consist of 27

x3x3 arrangement in I, J, K index directions. Since VORFN is y default, only the central block will be displayed and

All vertices can also be constrained by fixing x, y or z coordinates. Wthus constrained, the vertex movement ignores the above color coded geometric constraints. Set Pre-MeMesh sizes (parameters) can be set globally, or on the surfaces, curves or parts. These operations constitute the first four icons in the Mesh menu.These sizes then have to be applied to the blocking: Pre-Mesh Params > Update Sizes. SelectingthThe user may also fParams > Edge Params. The Number of nodes, initial and final node spacing, expansion ratios and mathematical meshing laws can be popposing parall Pre-Mesh Quality Before converting thsh(bar graph) of element quality in Quality. Different criteria such as determinant, angle and warpage can bchecked and displayed. Delete Blocks One of the main functions in the top down approach. After splitting blocks, some may need to be discarddefault, t VorfnThe VOblockingblocks, a 3turned off bactivated within the designated part.

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ks will a radial (o-grid) manner instead of the initial

ctions listed above, many other tools are available for

ows the user to build blocks by

ed blocks

erge vertices e merged to create degenerate blocks. If propagate merge

dit block s,

ove Vertices nually moving vertices on the geometry, other options allow

If Delete permanently within Delete Blocks is turned on, selected blocks will be removed, not just moved to the VORFN. The VORFN blocthen be reconfigured in Cartesian arrangement.

Functions Other

Besides the main funbuilding and fine-tuning the blocking topology: Create blocksBesides initializing, Create Block allselecting existing vertices and/or screen locations. Blocks can also be built by extruding from existing 3D block faces.Besides regular hex blocks, degenerate (wedge) blocks, unstructured and swept blocks can be created. Swept blocks (3D) and unstructur(2D) will allow you to have a different number of nodes across opposing edges. MVertices can bis turned on, all vertices up and downstream of those selected will also be merged, essentially removing the split. EVarious block editing commands including merge blocks, re-scale o-gridconvert block type etc. MBesides mayou to align vertices and to set coordinate locations of vertices. Transform Blocks

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ually splitting the edge or linking the edge shape with that of another edge. This gives the user better control of the flow of the mesh which can fix projection, skewness or other quality issues. Pre-Mesh Smooth Smoothing algorithms are available to automatically improve mesh quality before it is converted to either unstructured or multi-block mesh. Block Checks Check/fix is used to try and automatically fix the database if any serious errors arise. Also, left-handed (inverted) blocks can be automatically detected and fixed. Visibility Controls Most of the visibility controls, such as toggling objects on/off and right mouse clicking for display options are discussed in the Introduction. The same applies for the Blocking tree and its sub-categories. Once a blocking is initialized or a block file is loaded (File > Blocking > Open Blocking) a new category, Blocking, is created in the model tree. Sub-categories within blocking are: Subsets Vertices Edges Faces Blocks Pre-Mesh Topology Edges are turned on by default. Most of the time, edges are the only type that needs to be displayed in order to perform the majority of the

Copy or move blocks either by translation, rotation, mirror or scale. Allows the user to build blocking on one portion of the model and copyand move to capture other portions that are topologically similar. Edit Edge Allows the user to shape the edges, either by man

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functions. A crosshairs representing the vertices (block corners) will also ly necessary to display when certain

info desired.

e of the Pre-Mesh display option is projection type: n: Will simply interpolate all nodes without projecting to

eometry. Useful if a quick mesh preview is desired, for example to atterns.

Pro ject vertex nodes onto geometry. All other nodes are interpolated. Pro oject all nodes along edges. All interior face nodes are al output of 2D planar grids. Project Face: The default setting. Projects all boundary nodes, including those in the face interior. al volumetric nodes are interpolated. Required for final output of 3D volumetric grids. ScaAnother display option within Pre-Mesh. With this function, the user can visu canning or scrolling a logical (I, J, K

ote: The scan plane control displays I, J, K index dimensions as 0, 1, 2 nsions begin with 3. Additional o-grids

lanking

Index Control

be displayed. Vertices are onrmation is

Turning on Pre-Mesh will display the surface mesh. The user will be asked to compute the mesh if any changes have been made since the previous calculation. Projection Options OnNo Projectiogvisually check distribution p

ject Vertices: Will pro

ject Edges: Will printerpolated. Required for fin

Only intern

n Planes

alize the interior volume mesh by s) index plane through the model.

Nrespectively. O-grid index dimewill have an index of 4, 5, etc. BThis display option under the Blocking Display Tree simply blanks or turns off selected blocks to reduce screen clutter or if one wants to focus

aller set of blocks. on a sm

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option within the Blocking Display tree, this turns blocks on toggling up and down one or more of the I, J, K or radial (o-es. The index control menu will appear in the lower right hand

the screen in the same area where the quality histogram is ed. If the histogram is turned on, it will take precedence and the

index control will be displayed as a pop-up menu.

As a displayand off by grid) indic

rner of codisplay