activity sheet airfoil and wing fluent simulation
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ACTIVITY SHEETAIRFOIL
FLUENT SIMULATIONAE4015 COMPUTATIONAL AERODYNAMICS
EMA AMALIA, ST., MT.
SIMULATION OF AIRFOIL NACA 65(2)-415
PREPARING GEOMETRY OF THE AIRFOIL
• TO DO SIMULATION ON AIRFOIL NACA 65(2)-415, HERE WE WILL USE ICEM CFD TO
CONSTRUCT GEOMETRY
• AIRFOIL THAT HAS BEEN CONSTRUCTED USING SPACECLAIM IS FOR CONSTRUCTING WING. IT
WON’T BE GOOD FOR AIRFOIL CFD SIMULATION
PREPARING GEOMETRY OF THE AIRFOIL
• NOW WE WILL CONTINUE, FIRST, WE DOWNLOAD THE AIRFOIL COORDINATE FROM “UIUC
AIRFOIL DATA SITE” UNDER THE ALPHABET “N” (HTTPS://M-
SELIG.AE.ILLINOIS.EDU/ADS/COORD_DATABASE.HTML#N) AND CHOOSE “NACA652415.DAT”
PREPARING GEOMETRY OF THE AIRFOIL
• OPEN THE FILE “NACA652415.DAT” IN MS EXCEL, ADD AN ADDITIONAL COLUMN FOR Z VALUE OF 0 (BECAUSE
WE WORK IN 2 DIMENSIONAL).
• ADD SOME INFO AT THE TOP OF FILE AS IN THE NEXT SLIDE
• REMEMBER THAT THE SEQUENCE OF AIRFOIL COORDINATE DATA SHOULD CONSIST OF TWO CURVES:
1. FROM LEADING EDGE TO TRAILING EDGE THROUGH UPPER SURFACE
2. FROM LEADING EDGE TO TRAILING EDGE THROUGH LOWER SURFACE
• REMEMBER TO ADJUST THE NUMBER OF POINTS TO MATCH WITH THE NUMBER OF COORDINATE
DATA POINTS. FOR EXAMPLE, IF YOU WRITE DOWN THE DATA NUMBER IS 26, YOU SHOULD MODIFY
THE COORDINATE DATA POINTS TO BE 26 TOO.
Original
Data
From
NACA652415.DAT
Number of point
in each curve
Number of curves
Change sequence of upper surface
to be from LE to TE
Adding a point of 0,0,0 to upper
surface so that the number of point
will be 26 for each curves
Additional column of z
PREPARING GEOMETRY OF THE AIRFOIL
• COPY THE MODIFIED DATA OF AIRFOIL COORDINATE TO A NEW SHEET, AND SAVE IN FORMAT
“TEXT (TAB DELIMITED)” AS *.DAT”, FOR EXAMPLE “NACA652415PROFILE.DAT”. BECAUSE EXCEL
HAS NO FORMAT OF “*.DAT”, JUST ENTER “NACA652415PROFILE.DAT” AS INPUT TO FILE NAME
• NOW, THE *.DAT FILE IS READY TO BE IMPORTED FROM ICEM CFD
PREPARING GEOMETRY OF THE AIRFOIL
• LAUNCH ICEM CFD:
1. FROM WORKBENCH: DRAG “ICEM CFD” FROM LEFT WINDOW TO MAIN WINDOW AND
RIGHT CLICK “MODEL”, CHOOSE “EDIT”. THEN ICEM CFD WILL BE LAUNCHED. OR DOUBLE CLICK
“MODEL”, AND ICEM CFD WILL BE LAUNCHED.
PREPARING GEOMETRY OF THE AIRFOIL
• OR LAUNCH ICEM CFD STANDALONE
PREPARING GEOMETRY OF THE AIRFOIL
• THE DIFFERENCE BETWEEN ICEM CFD LAUNCHED FROM WORKBENCH AND STANDALONE
Launched from Workbench
Launched Standalone
PREPARING GEOMETRY OF THE AIRFOIL
• IF YOU WORK WITH WORKBENCH, DON’T FORGET TO “SAVE PROJECT” FROM FILE TAB (DO
NOT USE UPDATE PROJECT), EXIT TO WORKBENCH, AND SAVE YOUR WORKBENCH PROJECT IN
DIFFERENT NAMES FOR SOME STEPS, IN CASE YOU DO A WRONG STEP, YOU DON’T NEED TO
REPEAT FROM ZERO.
PREPARING GEOMETRY OF THE AIRFOIL
• IF YOU WORK WITH ICEM CFD STANDALONE, DON’T FORGET TO “SAVE PROJECT AS”
FREQUENTLY WITH DIFFERENT NAMES FOR SOME STEPS, SO THAT IF YOU DO A WRONG STEP,
YOU DON’T NEED TO START FROM ZERO.
(YOU CAN DO THIS FROM “FILE” TAB, AND CHOOSE “SAVE PROJECT AS”, THEN WRITE DOWN
THE NAME OF INTERMEDIATE FILE, FOR EXAMPLE: “NACA652415 STEP 1. PRJ”
PREPARING GEOMETRY OF THE AIRFOIL
• IN THIS ACTIVITY SHEET, THE GUIDELINES WILL BE MAINLY DONE FROM WORKBENCH. BUT IF
YOU WORK FROM STANDALONE ICEM CFD, IT WILL BE VERY SIMILAR.
PREPARING GEOMETRY OF THE AIRFOIL
• FROM ICEM CFD, CHOOSE FILE => IMPORT GEOMETRY => FORMATTED POINT DATA. SELECT
THE *.DAT FILE “ (FOR EXAMPLE: NACA652415PROFILE.DAT)
PREPARING GEOMETRY OF THE AIRFOIL
• THEN CLICK APPLY IN LOWER-LEFT WINDOW
PREPARING GEOMETRY OF THE AIRFOIL
• IF WE CHECK “POINTS” IN STRUCTURE TREE, THEN POINTS OF AIRFOIL COORDINATE WILL
APPEAR
PREPARING GEOMETRY OF THE AIRFOIL• RENAME THE PARTS. FOR EXAMPLE: CRVS BECOMES AIRFOIL BY RIGHT CLICK THE PARTS
• DELETE UNNECESSARY PARTS, FOR EXAMPLE “SURFS”
MAKING COMPUTATIONAL DOMAIN
• NOW WE WILL MAKE COMPUTATIONAL DOMAIN
• WE WILL CREATE SOME POINTS AS FOLLOWS:
(-20,0,0); (0,20,0); (0,-20,0); (21,20,0), (21,-20,0)
MAKING COMPUTATIONAL DOMAIN• FROM GEOMETRY TAB, CHOOSE “CREATE POINT”, CHOOSE “XYZ” OPTION TO INPUT COORDINATES
Uncheck
XYZ option
Enter coordinates
of points
MAKING COMPUTATIONAL DOMAIN• REPEAT TO DRAW POINTS OF OUTER BOUNDARIES OF COMPUTATIONAL DOMAIN
(-20,0,0)
(0,20,0)
(0,-20,0)
(21,20,0)
(21,-20,0)
MAKING COMPUTATIONAL DOMAIN
• CREATE CURVE FROM GEOMETRY TAB, CONNECT THE OUTER BOUNDARIES OF
COMPUTATIONAL DOMAIN
Uncheck
Choose this option
for straight liines
Click to select a point, middle click to confirm,
Repeat for all straight lines
MAKING COMPUTATIONAL DOMAIN• CREATE CURVE FROM GEOMETRY TAB, CONNECT THE OUTER BOUNDARIES OF
COMPUTATIONAL DOMAIN
Uncheck
Choose this option
for half circle
Click to select three points that construct semi-circle
Boundary, middle click to confirm
MAKING COMPUTATIONAL DOMAIN• WE WILL MAKE SURFACE OF COMPUTATIONAL DOMAIN
• CLICK “CREATE SURFACE” IN GEOMETRY TAB, AND CHOOSE “SIMPLE SURFACE” SELECT CURVES
OF OUTER BOUNDARIES BY CLICKS AND MIDDLE CLICKS TO CONFIRM
Enter the name of part as “Fluid”
Uncheck
Choose this simple surface option
CREATE BLOCKING• CHOOSE BLOCKING TAB, CLICK CREATE BLOCK
• CHOOSE PART OF “FLUID” AS BLOCKING, AND SELECT “2D PLANAR”, CLICK APPLY
CREATE BLOCKING• STILL IN BLOCKING TAB, CLICK ASSOCIATE AND “ASSOCIATE EDGE TO CURVE”
• CHOOSE EDGE OF BACK BOUNDARY TO ASSOCIATE WITH BACK CURVE WITH CLICK AND
MIDDLE-CLICK UNTIL THE EDGES BECOME GREEN.
• CHOOSE EDGE OF UPPER, FRONT, AND
LOWER BOUNDARIES TO ASSOCIATE WITH UPPER, SEMI-CIRCLE, AND LOWER CURVES WITH
CLICK AND MIDDLE-CLICK UNTIL THE EDGES BECOME GREEN.
CREATE BLOCKING• STILL IN BLOCKING TAB, CLICK ASSOCIATE MENU, CHOOSE “SNAP PROJECT VERTICES”
MODIFY BLOCKING
• MODIFY EXISTING BLOCKING BY EDIT EDGE AND SPLIT EDGE
• SELECT METHOD SPLINE TO EDIT EDGE IN NEAR SEMI-CIRCLE CURVE SO
THAT THE EDGE WILL FOLLOW THE CURVE’S SHAPE.
MODIFY BLOCKING
• AND SELECT METHOD LINEAR TO GRADUALLY CHANGE THE SHAPE OF THE REST EDGE TO
FOLLOW THE CURVES. NOW THE SHAPE OF THE BLOCKING IS THE SAME WITH THE DOMAIN.
MODIFY THE BLOCK• STILL IN BLOCKING MENU, CHOOSE SPLIT BLOCK AND CHOOSE OGRID BLOCK
• SELECT BLOCK BY CLICKING AREA INSIDE OUTER BOUNDARIES, AND SELECT EDGE OF OUTLET
CLICK APPLY
MODIFY THE BLOCK• USE MOVE VERTEX AND CLICK IN LOWER-LEFT WINDOW, THEN MOVE VERTICES SO
THAT THE POSITIONS WILL BE AS IN THE NEXT TWO FIGURE
Select vertices by click
And drag with mouse
To their new places
this vertex
this vertex
this vertex
this vertex
Vertices in their new positions
MODIFY BLOCK
• STILL IN BLOCKING TAB, SELECT SPLIT BLOCK AND CLICK SPLIT BLOCK
MODIFY BLOCK
• SELECT EDGE BEHIND AIRFOIL (THE RED EDGE) BY CLICK, DRAG THE MOUSE TO POSITION OF SPLIT
MODIFY BLOCK
• STILL FROM BLOCKING MENU, SELECT MERGE VERTICES AND COLLAPSE BLOCK ,
MODIFY BLOCK
• ACTIVATE BLOCKS
This edge This block to
collapse
• Click the edge, click block to collapse, middle click
MODIFY THE BLOCK• USE MOVE VERTEX AND CLICK IN LOWER-LEFT WINDOW, THEN MOVE VERTICES SO
THAT THE POSITIONS WILL BE AS IN THE NEXT TWO FIGURE
Select vertices by click
And drag with mouse
To their new places
This vertex
Become at this position
MODIFY BLOCK• STILL FROM BLOCKING TAB, CHOOSE ASSOCIATE , AND ASSOCIATE VERTEX TO POINT
Select this vertex
Click this point
So that the vertex turned to red
MODIFY BLOCK
• STILL FROM BLOCKING TAB, CHOOSE ASSOCIATE , AND ASSOCIATE VERTEX TO POINT
MODIFY BLOCK
• ASSOCIATE TWO VERTICES TO TWO POINTS AS FOLLOWS
This point
This point
This vertex
This vertex
Vertex turned into red
Vertex turned into red
MODIFY BLOCK• STILL IN BLOCKING TAB, CLICK ASSOCIATE AND “ASSOCIATE EDGE TO CURVE”
Check “project
vertices”
Click this edges to associate with
Airfoil curves, then middle click
Click these two
curves, middle click
MODIFY BLOCKING
• MODIFY EXISTING BLOCKING BY EDIT EDGE AND SPLIT EDGE
• SELECT METHOD LINEAR TO EDIT EDGES INSIDE AIRFOIL TO FOLLOW
AIRFOIL CURVE
Make these edges follow
The airfoil curve
By split edge
With linear method
MODIFY BLOCK
• STILL IN BLOCKING TAB, CHOOSE SPLIT BLOCK , AND CLICK SPLIT BLOCK AND
SELECT THE EDGE (THE RED ONE) BY CLICK SO THAT THERE WILL BE AN ADDITIONAL BLOCK
AROUND AIRFOIL. THEN MIDDLE CLICK TO CONFIRM.
Additional block
Near airfoil
MODIFY BLOCK
• WE WILL DELETE BLOCK INSIDE THE AIRFOIL BY CHOOSING DELETE BLOCK
• CLICK THE BLOCK INSIDE AIRFOIL, MIDDLE CLICK TO CONFIRM TO DELETE.
We will delete this block
• THERE IS NO MORE BLOCK INSIDE THE AIRFOIL
• CHECK BLOCKS IN UPPER LEFT WINDOW TO VIEW BLOCKS IN OUR COMPUTATIONAL DOMAIN
PREPARING FOR MESHING
• IF YOU WORK WITH WORKBENCH, SAVE THE WORKBENCH WITH DIFFERENT NAME BEFORE YOU
DO MESHING
• IF YOU WORK WITH STANDALONE ICEM CFD, SAVE THE PROJECT WITH DIFFERENT NAME BEFORE
YOU DO MESHING
THIS STEP ENSURE YOU TO HAVE A FILE OF GEOMETRY WITH COMPLETE BLOCKING BEFORE MESHING,
SO THAT IF YOU MAKE A MISTAKE IN MESHING YOU CAN GO BACK AND RESTART FROM THIS FILE.
• FOR EXAMPLE, HERE WE SAVE WORKBENCH PROJECT WITH COMPLETE BLOCKING
NOW WE ARE READY FOR MESHING
• FOR EXAMPLE, WE SAVE AN INTERMEDIATE WORKBENCH PROJECT AS FOLLOWS
• YOU CAN DO THE SIMILAR IF YOU WORK WITH STANDALONE ICEM CFD
MESHING• CALCULATING ESTIMATED WALL DISTANCE BY Y+ = 1 (HTTPS://WWW.CFD-
ONLINE.COM/TOOLS/YPLUS.PHP) => CHORD IS 1.O (TO BE ADJUSTED TO 1.625 LATER)
The estimated wall distance
MESHING
• OPEN YOUR AIRFOIL GEOMETRY COMPLETE WITH BLOCKING IN ICEM CFD EITHER FROM
WORKBENCH OR FROM ICEM CFD STANDALONE
• UNCHECK BLOCKS
MESHING
• STILL IN BLOCKING TAB, CHOOSE PRE-MESH PARAM AND EDGE PARAMS
• SELECT EDGE AS IN NEXT SLIDE (RED ONE)
• SET PARAMETER IN LOWER-LEFT WINDOW AS FOLLOWS
This from y+=1
Scroll
MESHING
• SET COPY TO PARAMETERS => ALL PARALLEL EDGES
• CLICK APPLY
• RECOMPUTE PRE-MESH BY RIGHT CLICK ON THE TREE OF “PRE-MESH”
MESHING• WE STILL SEE THAT THE PRE-MESH IS PENETRATING THE AIRFOIL SURFACE
• FROM BLOCKING TAB, CLICK (“GRID PARAMS”) AND CLICK (“UPDATE SIZES”), APPLY
Now, we get pre-mesh that not penetrating airfoil
MESHING
• REPEAT THE PREVIOUS PROCEDURE TO SET MESH AT THE EDGE
• STILL IN BLOCKING TAB, CHOOSE PRE-MESH PARAM AND EDGE PARAMS
• SELECT EDGE AS IN NEXT SLIDE (RED ONE)
• SET PARAMETER IN LOWER-LEFT WINDOW AS FOLLOWS
Scroll This from y+=1
Set copy to parameters => All Parallel Edges
Click apply
• RECOMPUTE PRE-MESH, ACTIVATE PRE-MESH
MESHING
• WE WILL SET MESH FOR OTHER NECESSARY EDGES
MESHING
• STILL IN BLOCKING TAB, CHOOSE PRE-MESH PARAM AND EDGE PARAMS
• SELECT EDGE BEHIND THE AIRFOIL (RED ONE WITH ARROWS)
• SET NODES FOR EXAMPLE 1500
• SET MESH LAW AS “BIGEOMETRIC”
• LET OTHER VALUES AS GIVEN BY SOFTWARE
• SET COPY PARAMETER => ALL PARALLEL EDGES
• CLICK APPLY AND RECOMPUTE PRE-MESH AND ACTIVATE IT
MESHING
• STILL IN BLOCKING TAB, CHOOSE PRE-MESH PARAM AND EDGE PARAMS
• SELECT EDGES OF SURFACE OF AIRFOIL (RED ONE WITH ARROWS)
• SET NODES FOR EXAMPLE 400
• SET MESH LAW AS “BIGEOMETRIC”
• LET OTHER VALUES AS GIVEN BY SOFTWARE
• SET COPY PARAMETER => ALL PARALLEL EDGES
• CLICK APPLY, RECOMPUTE PRE-MESH AND ACTIVATE IT
MESHING
• STILL IN BLOCKING TAB, CHOOSE PRE-MESH PARAM AND EDGE PARAMS
• SELECT EDGE IN FRONT OF LEADING EDGE OF AIRFOIL(RED ONE WITH ARROWS)
• SET NODES FOR EXAMPLE 50
• SET MESH LAW AS “BIGEOMETRIC”
• LET OTHER VALUES AS GIVEN BY SOFTWARE
• SET COPY PARAMETER => ALL PARALLEL EDGES
• CLICK APPLY, RECOMPUTE PRE-MESH AND ACTIVATE IT
MESHING
• STILL IN BLOCKING TAB, CHOOSE PRE-MESH PARAM AND EDGE PARAMS
• SELECT EDGE NEAR FARFIELD (RED ONE WITH ARROWS)
• SET NODES FOR EXAMPLE 600
• SET MESH LAW AS “BIGEOMETRIC”
• LET OTHER VALUES AS GIVEN BY SOFTWARE
• SET COPY PARAMETER => ALL PARALLEL EDGES
• CLICK APPLY, RECOMPUTE PRE-MESH AND ACTIVATE IT
MESHING
• RIGHT CLICK ON PRE-MESH, AND CHOOSE “CONVERT TO UNSTRUCT MESH”
• IF THERE IS A WINDOW THAT “MESH ALREADY EXISTS”, CLICK “REPLACE”
• NOW WE HAVE ALREADY HAD A MESH
NOW WE ARE READY FOR SIMULATION
SET SOLVER
• CHOOSE OUTPUT MESH TAB AND CHOOSE SELECT SOLVER
• CHOOSE ANSYS FLUENT
SET BOUNDARY CONDITIONS• FROM OUTPUT MESH TAB, CHOOSE (“BOUNDARY CONDITIONS”)
• FIRST, SET BOUNDARY CONDITION FOR “AIRFOIL” THAT APPEARS IN “EDGES”
• FOLLOW STEPS IN THE NEXT SLIDE
1. Click “create new”
2. Choose “wall”
3. Click “Okay”
SET BOUNDARY CONDITIONS
• THEN SET BOUNDARY CONDITION OF FARFIELD
• FROM “?MIXED/UNKNOWN” , CHOOSE FARFIELD
• FOLLOW STEPS IN THE NEXT SLIDE
1. Click “create new”
2. Choose “velocity inlet”
3. Click “okay”
SET BOUNDARY CONDITIONS
• SET THE BOUNDARY CONDITION OF FLUID
• FROM “? MIXED/UNKNOWN”, CHOOSE “FLUID”
• FOLLOW STEPS IN THE NEXT SLIDE
1. Click “create new”
2. Choose “fluid”
3. Click “Okay”
SET BOUNDARY CONDITIONS
• THEN WE WILL HAVE COMPLETE BOUNDARY CONDITIONS
• CLICK ACCEPT
WRITE OUTPUT FILE• FROM OUTPUT MESH TAB, CHOOSE (“WRITE OUTPUT”)
WRITE OUTPUT FILE
• CLICK OPEN FOR DEFAULT *.UNS FILE WHEN ASKED
WRITE OUTPUT FILE
• BECAUSE WE WILL OPEN FLUENT MESH BY FLUENT STANDALONE, NAME MESH WITH A UNIQUE
NAME.
• MAKE SURE THE CASE IS “2D”
Remember this working directory and the name of mesh file
PREPARING FOR SIMULATION IN FLUENT
• SAVE YOUR PROJECT AND CLOSE YOUR WORKBENCH OR STANDALONE ICEM CFD
• LAUNCH STANDALONE FLUENT IN 2D CASE WITH DOUBLE PRECISION OPTION
• CLICK “OK”
SIMULATION IN FLUENT
SIMULATION IN FLUENT
• CHOOSE FILE => READ => MESH
SIMULATION IN FLUENT
• CHOOSE THE MESH FILE
THAT WE SAVED
PREVIOUSLY
• CLICK OK
• MESH DISPLAYED IN FLUENT
SIMULATION IN FLUENT
• FIRST, WE WILL SCALE THE GEOMETRY AND MESH OF AIRFOIL TO HAVE A CHORD LENGTH OF
1.625.
• FROM GENERAL SETUP, CLICK “SCALE”
SIMULATION IN FLUENT• IN SCALING MENU, CHOOSE “SPECIFY SCALING FACTOR”
• ENTER FACTORS OF 1.625 FOR BOTH X AND Y, CLICK “SCALE” UNTIL THE VALUES ARE
CHANGED
SIMULATION IN FLUENT
• AFTER SCALING, AGAIN IN GENERAL SETUP, WE MAKE SURE THAT THE SETUP IS AS BELOW
SIMULATION IN FLUENT
• IN MODELS SETUP, CLICK “VISCOUS” AND CHOOSE “SPALART ALMARAS”
• CLICK OK
SIMULATION IN FLUENT
• IN MATERIALS SETUP, CHOOSE UNDER “FLUID”: “AIR” UNTIL A POP WINDOW APPEARS
• MAKE SURE THAT WE CHOOSE AIR AT SEA LEVEL CONDITION AS IN THE NEXT SLIDE
• CLICK CHANGE/CREATE AND CLICK CLOSE
SIMULATION IN FLUENT• IN CELL-ZONE CONDITIONS, CLICK “FLUID”, AND CLICK “OPERATING CONDITIONS”
SIMULATION IN FLUENT• ENTER 1 ATM OR 101325 PA FOR A POSITION OF FARFIELD IN THE FRONT. HERE WE USE THE
POINT OF (-32.5,0)
SIMULATION IN FLUENT
• WE CHECK BOUNDARY CONDITIONS
• AIRFOIL IS WALL
SIMULATION IN FLUENT
• FARFIELD IS VELOCITY INLET
• CLICK “EDIT”
SIMULATION IN FLUENT• SET VELOCITY AS “COMPONENT” AND ENTER THE VALUE OF FREESTREAM VELOCITY OF 26.82
M/S
SIMULATION IN FLUENT
• INT_FLUID AS “INTERIOR”
SIMULATION IN FLUENT
• SET REFERENCE VALUES AS FOLLOWS
SIMULATION IN FLUENT• IN MONITORS, WE WILL MAKE ADDITIONAL MONITORS OF CL, CD, AND CM. CLICK “REPORT
PLOTS” AND CLICK “NEW”
SIMULATION IN FLUENT• CREATE DRAG MONITORS
SIMULATION IN FLUENT
• DRAG REPORT DEFINITION
SIMULATION IN FLUENT
• CREATE LIFT MONITORS
SIMULATION IN FLUENT
• LIFT REPORT DEFINITIONS
SIMULATION IN FLUENT
• CREATE MOMENT MONITORS
SIMULATION IN FLUENT
• MOMENT REPORTS DEFINITION0.25chord
SIMULATION IN FLUENT
• IN SOLUTION INITIALIZATION, CHOOSE “STANDARD INITIALIZATION” AND COMPUTE FROM
“FARFIELD” AND LET OTHER VALUES AUTOMATICALLY DETERMINED BY SOFTWARE
• CLICK “INITIALIZE”
Click “Initialize”
SIMULATION IN FLUENT
• NOW, WE ARE READY TO RUN CALCULATION.
• ENTER ITERATION OF 500, WHICH COULD BE REPEATED LATER IF NOT CONVERGENT.
• BECAUSE NOT SET, THE CONVERGENCE CRITERIA WILL BE BY DEFAULT 1E-4.
• CLICK “CALCULATE” TO START SIMULATION IN FLUENT
SIMULATION IN FLUENT
• SIMULATION WILL TAKE ABOUT 8800 - 9800 ITERATIONS FOR ABOUT 7-16 HOURS
SIMULATION TO CONVERGED (AT I7 OR I5 PROCESSOR).
• YOU CAN’T DO ITERATION FOR EACH 1000 ITERATIONS AND SAVE THE CASE & DATA FOR
EACH 1000 ITERATIONS AND CONTINUE (DO NOT INITIALIZE, JUST CLICK CALCULATE)
• DON’T FORGET TO SAVE THE WORK FROM FILE => WRITE => CASE & DATA
• THE RESULT WILL BE EVALUATED BY EXPERIMENTAL RESULT AFTER POST-PROCESSING
NOW WE ARE READY FOR POST-PROCESSING
DISPLAYING LIFT COEFFICIENT
• WE WILL DISPLAY THE RESULT OF LIFT. CLICK “REPORTS”, CLICK “FORCES”, CLICK “SET UP” AND
A POP-UP WINDOW APPEARS
• THEN SET “DIRECTION VECTOR” OF Y AS 1 BECAUSE FOR ANGLE OF ATTACK 0 DEGREE, THE
LIFT FORCE IS IN Y POSITIVE DIRECTION.
• CLICK “PRINT” AND A LIFT COEFFICIENT VALUE WILL APPEAR IN LOWER-RIGHT WINDOW
DISPLAYING DRAG COEFFICIENT
• WE WILL DISPLAY THE RESULT OF DRAG. CLICK “REPORTS”, CLICK “FORCES”, CLICK “SET UP”
AND A POP-UP WINDOW APPEARS
• THEN SET “DIRECTION VECTOR” OF X AS 1 BECAUSE FOR ANGLE OF ATTACK 0 DEGREE, THE
DRAG FORCE IS IN X POSITIVE DIRECTION.
• CLICK “PRINT” AND YOU WILL SEE THE DRAG COEFFICIENT VALUE IN LOWER-RIGHT WINDOW
WRITING THE LIFT AND DRAG COEFFICIENT TO FILE• YOU CAN SAVE THE LIFT OR DRAG COEFFICIENT TO FILE BY CLICK “WRITE” INSTEAD OF “PRINT”
THEN INPUT THE FILE NAME
COMPARING WITH EXPERIMENTAL DATA
• IT IS IMPORTANT TO COMPARE OUR RESULT OF CFD SIMULATION WITH ANOTHER DATA TO
KNOW THE QUALITY OF RESULT. HERE WE WILL COMPARE WITH EXPERIMENTAL DATA OF
AIRFOIL NACA 65(2)-415 TAKEN FROM NACA REPORT. THE FILE OF NACA REPORT WILL BE
PROVIDED.
From experimental at 0 degree with Reynolds number 3e6, lift coefficient is 0.3 and drag coefficient is 0.007
COMPARING WITH EXPERIMENTAL DATA
• FROM EXPERIMENTAL DATA, AT 0 DEGREE WITH REYNOLDS NUMBER OF 3 MILLIONS, LIFT
COEFFICIENT IS 0.3 AND DRAG COEFFICIENT IS 0.007 (CL/CD (AERODYNAMICS EFFICIENCY) IS
ABOUT 42)
• THE RESULT OF CFD SIMULATION, THE LIFT COEFFICIENT IS 0.548 AND DRAG COEFFICIENT IS
0.0128 (CL/CD (AERODYNAMICS EFFICIENCY) IS ABOUT 42)
• WE CAN SEE THAT THE CFD SIMULATION IS IN MEDIUM QUALITY, BECAUSE IT HAS THE SAME
ORDER WITH EXPERIMENTAL RESULT, BUT IF YOU WILL USE CFD SIMULATION RESULT FOR A
PROJECT, YOU SHOULD MODIFY THE MESHING OR CHANGE TURBULENCE MODEL USED.
DISPLAYING ABSOLUTE PRESSURE CONTOUR
• IT IS IMPORTANT TOO TO CHECK WHETHER THE TOTAL PRESSURE CONTOUR IS AS IT SHOULD
BE, WHICH IS 1 ATM AT FARFIELD.
• CLICK “GRAPHICS”, CLICK “CONTOURS”, CLICK “SET UP” UNTIL A POP-UP WINDOW APPEARS.
• CHOOSE “PRESSURE” AND “ABSOLUTE PRESSURE”
• CHOOSE “INT_FLUID” OF SURFACE
• CLICK “COMPUTE”, WAIT, AND CLICK “SAVE/DISPLAY”.
• USE “FIT TO WINDOW” TO SEE THE WHOLE DOMAIN.
The CFD simulation results in correct values of 1 atm (about 1.01325e5 Pa) at farfield
SHOWING STATIC PRESSURE CONTOURS• WE WILL CHECK STATIC PRESSURE CONTOURS AROUND THE AIRFOIL WHETHER IT HAVE A
NEGATIVE STATIC PRESSURE ON THE UPPER SURFACE AS IT SHOULD BE.
• CLICK “GRAPHICS”, CLICK “CONTOURS”, CLICK “SET UP” UNTIL A POP WINDOW APPEARS.
• CHOOSE “PRESSURE” AND “STATIC PRESSURE”
• CHOOSE “INT_FLUID” OF SURFACE
• CLICK “COMPUTE”, WAIT, AND CLICK “SAVE/DISPLAY”. CHOOSE THE WINDOW TO VIEW THE
STATIC PRESSURE CONTOUR.
• USE “ZOOM TO AREA” TO SEE CONTOUR NEAR THE AIRFOIL.
SAVING CONTOUR PLOT
• IF YOU NEED TO SAVE THE CONTOUR PLOT, CHOOSE “SAVE PICTURE” FROM THE ICON.
• THEN A POP UP WINDOW WILL APPEAR, ENTER THE THE FILE TYPE.
• CLICK “SAVE”, AND ENTER THE FILE NAME.
EXAMPLE OF JPEG PICTURE OF STATIC PRESSURE CONTOUR
EVALUATION OF STATIC PRESSURE CONTOUR
• WE SEE FROM STATIC PRESSURE CONTOUR THAT THERE IS A NEGATIVE STATIC PRESSURE AREA
ON UPPER SURFACE OF AIRFOIL, THIS FACT CONFIRM THAT THE CFD SIMULATION IS CORRECT
ACCORDING TO THEORY.
DISPLAYING VELOCITY CONTOUR
• WE WILL CHECK THAT AT FARFIELD, THE VELOCITY SHOULD BE 26.82 M/S.
• CLICK “GRAPHICS”, CLICK “CONTOURS”, CLICK “SET UP” UNTIL A POP WINDOW APPEARS.
• CHOOSE “VELOCITY”, CHOOSE “VELOCITY MAGNITUDE”
• CLICK “COMPUTE”, WAIT, CLICK “SAVE/DISPLAY”
• SELECT THE WINDOW TO SHOW THE CONTOUR OF VELOCITY
• SELECT “FIT TO WINDOW” TO SEE WHOLE OF DOMAIN
We see that the velocity near of farfield is of correct value of 26.82 m/s
26.82
NOTE ON POST-PROCESSING
• THERE IS MANY THINGS CAN BE DISPLAYED IN POST-PROCESSING, YOU CAN TRY BY YOURSELF
• FOR EXAMPLE, DISPLAYING VELOCITY VECTORS NEAR AIRFOIL SURFACE, AND CHECKING
VELOCITY PROFILE OF BOUNDARY LAYER.
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