Training Manual Chapter 2 CFD Analysis with ANSYSFLOTRAN

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Training Manual Chapter 2 CFD Analysis with ANSYS/FLOTRAN The Example Problem

Training Manual Chapter 2 CFD Analysis with ANSYS/FLOTRAN The Example Problem

An Example Problem !! Training Manual • Objective: Peform laminar analysis of a relatively

An Example Problem !! Training Manual • Objective: Peform laminar analysis of a relatively slow moving flow and then increase the flow rate dramatically. Streamlines CFD Analysis with ANSYS/FLOTRAN • Flow of Air in a 2 D duct…. 001312 30 Nov 1999 2 -2

The Geometry Training Manual • Units of Length - Inches – Inlet length 3.

The Geometry Training Manual • Units of Length - Inches – Inlet length 3. 0 – Inlet height 0. 5 – Transition length 1. 0 – Outlet height 1. 0 – Outlet length 4. 0 CFD Analysis with ANSYS/FLOTRAN • This is Duct which has a smooth transition to a larger area. 001312 30 Nov 1999 2 -3

Properties - Conditions Training Manual – Property type is AIR-IN – Density will be

Properties - Conditions Training Manual – Property type is AIR-IN – Density will be 1. 1214 E-7 (lbf-s 2/in 4) – Viscosity will be 2. 6240 E-9 (lbf-s/in 2) • Conditions – Reference Pressure 14. 7 psi – Outlet Pressure 0 psi (relative pressure) – Default Temperature used : 293 K • Flow – Velocity of 10 inch/sec -> RE ~ 424 (laminar) – Note in 2 D the hydraulic diameter (used in the Reynolds Number) is twice the inlet height CFD Analysis with ANSYS/FLOTRAN • Use PSI system of units 001312 30 Nov 1999 2 -4

Set Preferences Training Manual CFD Analysis with ANSYS/FLOTRAN • Preferences provides a filter to

Set Preferences Training Manual CFD Analysis with ANSYS/FLOTRAN • Preferences provides a filter to prevent irrelevant information from being presented…. 001312 30 Nov 1999 2 -5

Establish Element Type Training Manual 2 - Choose 1 - Add 4 - Close

Establish Element Type Training Manual 2 - Choose 1 - Add 4 - Close 3 - OK CFD Analysis with ANSYS/FLOTRAN • Main Menu: Preprocessor-> Element Type->Add/Edit/Delete 001312 30 Nov 1999 2 -6

Geometry - Create Inlet/Outlet Regions • First – X 1=0, X 2=3 – Y

Geometry - Create Inlet/Outlet Regions • First – X 1=0, X 2=3 – Y 1=0, Y 2=0. 5 – Click Apply • Second – X 1=4, X 2=8 – Y 1=0, Y 2=1 – Click OK CFD Analysis with ANSYS/FLOTRAN • Preprocessor>Modeling>Create Areas> Rectangle (By Dimensions) Training Manual 001312 30 Nov 1999 2 -7

The Two Rectangles Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2

The Two Rectangles Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -8

Transition Region Between Them Training Manual • Preprocessor>Modeling>Create Lines (Tangent to 2 Lines) •

Transition Region Between Them Training Manual • Preprocessor>Modeling>Create Lines (Tangent to 2 Lines) • Follow the Instructions carefully in the resulting PICKERS – There will be four successive choices • Check your result with the following page…. CFD Analysis with ANSYS/FLOTRAN • Create a smooth transition line between the two 001312 30 Nov 1999 2 -9

The Smooth Transition Line CFD Analysis with ANSYS/FLOTRAN • Tangency to two lines requires

The Smooth Transition Line CFD Analysis with ANSYS/FLOTRAN • Tangency to two lines requires choosing the proper endpoints…. . Training Manual 001312 30 Nov 1999 2 -10

The Transition Area Training Manual • Choose 4 keypoints in response to the PICKER,

The Transition Area Training Manual • Choose 4 keypoints in response to the PICKER, then OK 4 1 3 CFD Analysis with ANSYS/FLOTRAN • Preprocessor>Modeling>Create> Area >Arbitrary 2 001312 30 Nov 1999 2 -11

Geometry is Finished!! Line Plot CFD Analysis with ANSYS/FLOTRAN Area Plot Training Manual 001312

Geometry is Finished!! Line Plot CFD Analysis with ANSYS/FLOTRAN Area Plot Training Manual 001312 30 Nov 1999 2 -12

Boundary Conditions – Do not require re-application upon re-meshing • Preprocessor>Loads>Apply>Velocity> Lines • We

Boundary Conditions – Do not require re-application upon re-meshing • Preprocessor>Loads>Apply>Velocity> Lines • We will apply Velocities and Pressures – Inlets are Velocity or Pressure – Outlets are Pressure – Walls: Velocities are zero CFD Analysis with ANSYS/FLOTRAN • Use Solid Model Boundary Conditions Training Manual 001312 30 Nov 1999 2 -13

The Boundary Conditions Training Manual • Proper condition at boundary intersections is determined by

The Boundary Conditions Training Manual • Proper condition at boundary intersections is determined by FLOTRAN Walls Inlet: VX=10, VY=0 Walls Outlet PRES = 0 CFD Analysis with ANSYS/FLOTRAN • These boundary conditions are typical 001312 30 Nov 1999 2 -14

Solid Model Boundary Conditions 4 - Input Values, Do Endpoints of lines…OK 1 -Lines

Solid Model Boundary Conditions 4 - Input Values, Do Endpoints of lines…OK 1 -Lines 3 -OK 2 -Pick These 6 Lines CFD Analysis with ANSYS/FLOTRAN • Example for Walls Training Manual 001312 30 Nov 1999 2 -15

Remaining Boundaries. Training Manual Inlet Outlet CFD Analysis with ANSYS/FLOTRAN • Note that leaving

Remaining Boundaries. Training Manual Inlet Outlet CFD Analysis with ANSYS/FLOTRAN • Note that leaving a blank DOES NOT result in a zero condition being applied. . 001312 30 Nov 1999 2 -16

Control of the Display To prevent display of these symbols: Utility Menu: Plot. Ctrls>Symbols…

Control of the Display To prevent display of these symbols: Utility Menu: Plot. Ctrls>Symbols… Choose NONE and OK CFD Analysis with ANSYS/FLOTRAN This is a line plot after application of the Boundary Conditions Training Manual 001312 30 Nov 1999 2 -17

Preparation for Meshing Training Manual – Size Controls, Lines, Set • PICKER shows up

Preparation for Meshing Training Manual – Size Controls, Lines, Set • PICKER shows up and you choose the lines, OK – Set the number of divisions and the ratio, OK • Use these settings for line divisions Line Divisions • Lines NDIV Ratio • Transverse direction 12 -3 • Inlet Region - flow direction 16 -2 • Transition - flow direction 10 1 • Outlet - flow direction 18 2 • See next page for Mesh tool! SAVE Database Before Meshing…. CFD Analysis with ANSYS/FLOTRAN • Use the Mesh Tool 001312 30 Nov 1999 2 -18

Mesh Tool Training Manual 1 3 - OK Use FLIP if Line Bias is

Mesh Tool Training Manual 1 3 - OK Use FLIP if Line Bias is reversed CFD Analysis with ANSYS/FLOTRAN 2 - Choose Lines 001312 30 Nov 1999 2 -19

Element Size Box Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2

Element Size Box Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -20

Proper Line Divisions Training Manual • Remember to flip one of the outlet lines

Proper Line Divisions Training Manual • Remember to flip one of the outlet lines • Generally, Avoid large adjacent element size changes • The Four lines in the Y direction are the transverse lines • Inlet Lines Transition Outlet Lines (Flipped!) CFD Analysis with ANSYS/FLOTRAN • Four Different Groups of Lines must be done for this problem… 001312 30 Nov 1999 2 -21

Meshing Step Training Manual – 1: Choose Areas – 2: Mapped – 3: Quad

Meshing Step Training Manual – 1: Choose Areas – 2: Mapped – 3: Quad – 4: Mesh • PICKER comes up 1 – Pick All 3 • (Meshing Occurs) • 5: Close Meshtool 2 4 5 CFD Analysis with ANSYS/FLOTRAN • Use the Mesh Tool 001312 30 Nov 1999 2 -22

Now You Have a Mesh! CFD Analysis with ANSYS/FLOTRAN Picture Made with Reverse Video

Now You Have a Mesh! CFD Analysis with ANSYS/FLOTRAN Picture Made with Reverse Video (Plot. Ctrls>Style>Color>Reverse. Video Training Manual 001312 30 Nov 1999 2 -23

Now for the FLOTRAN Input • (Depending on Program Setup, you may need to

Now for the FLOTRAN Input • (Depending on Program Setup, you may need to access “Unabridged Menu”) CFD Analysis with ANSYS/FLOTRAN • Enter FLOTRAN Setup through PREP 7 or Solution Training Manual 001312 30 Nov 1999 2 -24

FLOTRAN Setup Training Manual NOW - Our Initial Analysis LATER - Follow On Work

FLOTRAN Setup Training Manual NOW - Our Initial Analysis LATER - Follow On Work CFD Analysis with ANSYS/FLOTRAN • We will be making changes to these portions of the Menu. 001312 30 Nov 1999 2 -25

Execution Control – We are not relying on the automatic termination criterion based on

Execution Control – We are not relying on the automatic termination criterion based on problem convergence OK! CFD Analysis with ANSYS/FLOTRAN • Choose 50 Global Iterations to Start with Training Manual 001312 30 Nov 1999 2 -26

Fluid Properties • OK CFD Analysis with ANSYS/FLOTRAN • Choose AIR-IN for the property

Fluid Properties • OK CFD Analysis with ANSYS/FLOTRAN • Choose AIR-IN for the property type for Density and Viscosity using scroll down menu…. Training Manual 001312 30 Nov 1999 2 -27

Resulting Screen (click OK) Training Manual CFD Analysis with ANSYS/FLOTRAN (Thermal conductivity and Specific

Resulting Screen (click OK) Training Manual CFD Analysis with ANSYS/FLOTRAN (Thermal conductivity and Specific Heat not needed) 001312 30 Nov 1999 2 -28

Flow Environment • Pressure: 14. 7 Psi • Nominal Temperature: 70 F • Offset

Flow Environment • Pressure: 14. 7 Psi • Nominal Temperature: 70 F • Offset Temperature: 460 R CFD Analysis with ANSYS/FLOTRAN • Reference Conditions are found as a subset: Training Manual • OK! 001312 30 Nov 1999 2 -29

FLOTRAN Execution • Run FLOTRAN • Execute 50 iterations, look at the results and

FLOTRAN Execution • Run FLOTRAN • Execute 50 iterations, look at the results and then run 50 more… • Convergence monitors indicate the normalized rate of change of the solution CFD Analysis with ANSYS/FLOTRAN • Done in SOLUTION: Training Manual 001312 30 Nov 1999 2 -30

Convergence Monitors Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -31

Convergence Monitors Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -31

More Convergence Monitors Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2

More Convergence Monitors Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -32

Post-Processing – Explicity read in a set of results (not automatically loaded) • Velocity

Post-Processing – Explicity read in a set of results (not automatically loaded) • Velocity Vectors • Nodal Solution Plots – Solid Color – Line Contours • Path Plots • Particle Traces CFD Analysis with ANSYS/FLOTRAN • FLOTRAN Post-Processing is fairly typical of ANSYS Training Manual 001312 30 Nov 1999 2 -33

Velocity Vectors Training Manual (Use this for Nodal Solution Plots…. ) CFD Analysis with

Velocity Vectors Training Manual (Use this for Nodal Solution Plots…. ) CFD Analysis with ANSYS/FLOTRAN • Plot Results>Predefined Vector Plot. . OK 001312 30 Nov 1999 2 -34

Vectors - Typical after 100 Global Iterations CFD Analysis with ANSYS/FLOTRAN 50 Global Iterations

Vectors - Typical after 100 Global Iterations CFD Analysis with ANSYS/FLOTRAN 50 Global Iterations Training Manual 001312 30 Nov 1999 2 -35

Nodal Results Plotting Training Manual – Utility Menu>Plot Ctrls>Device Options • Shading or Contours

Nodal Results Plotting Training Manual – Utility Menu>Plot Ctrls>Device Options • Shading or Contours • Choose DOF • OK CFD Analysis with ANSYS/FLOTRAN • Show up as solid color plots or lines depending on the device chosen 001312 30 Nov 1999 2 -36

Pressures (50, 100 Global Iterations) Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov

Pressures (50, 100 Global Iterations) Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -37

Results Training Manual • We also notice that the Convergence Monitors (Normalized rate of

Results Training Manual • We also notice that the Convergence Monitors (Normalized rate of change of each DOF) have leveled off…. – This implies solution is slightly oscillatory • We will modify the input slightly, choosing the SUPG (Streamline Upwind Petrov-Galerkin) formulation for the momentum equations… – The SUPG algorithm is less diffusive and more accurate (but sometimes less robust) than the default algorithm (MSU Monotone Streamline Upwind Method) CFD Analysis with ANSYS/FLOTRAN • We can’t tell the difference between the velocity vector plots, but it looks like the pressures have changed slightly. • Also, set the number of Global Iterations to 100 001312 30 Nov 1999 2 -38

Changing Advection OK! CFD Analysis with ANSYS/FLOTRAN • FLOTRAN Setup > Advection Training Manual

Changing Advection OK! CFD Analysis with ANSYS/FLOTRAN • FLOTRAN Setup > Advection Training Manual 001312 30 Nov 1999 2 -39

Convergence with SUPG Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2

Convergence with SUPG Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -40

Results Training Manual • Use of SUPG has given enhanced convergence. • We should

Results Training Manual • Use of SUPG has given enhanced convergence. • We should expect a less diffusive solution, and so the recirculation region may be better defined. CFD Analysis with ANSYS/FLOTRAN • We could continue, but you get the idea. . . 001312 30 Nov 1999 2 -41

Comparison of Vectors at 100, 200 GI Training Manual CFD Analysis with ANSYS/FLOTRAN Vectors

Comparison of Vectors at 100, 200 GI Training Manual CFD Analysis with ANSYS/FLOTRAN Vectors at 200 GI show more extensive recirculation 001312 30 Nov 1999 2 -42

Path Plots • Procedure -Path Operations – Define Path by Nodes • Choose Nodes

Path Plots • Procedure -Path Operations – Define Path by Nodes • Choose Nodes on either corner of the outlet – Map Onto Path • Choose VX and label it – Plot • On graph CFD Analysis with ANSYS/FLOTRAN • Look at the profile of VX along the outlet Training Manual 001312 30 Nov 1999 2 -43

Set up the Path Plot Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov

Set up the Path Plot Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -44

Path plot • OK • Name the Path • OK CFD Analysis with ANSYS/FLOTRAN

Path plot • OK • Name the Path • OK CFD Analysis with ANSYS/FLOTRAN • Pick the corner nodes Training Manual 001312 30 Nov 1999 2 -45

Path plot - Still More • Map Onto Path, Choose VX, Give it a

Path plot - Still More • Map Onto Path, Choose VX, Give it a Name, OK CFD Analysis with ANSYS/FLOTRAN • Read and dismiss the PDEF (path definition) box Training Manual 001312 30 Nov 1999 2 -46

Path Plot - Almost Done • Choose DOF, OK • And Then…. . .

Path Plot - Almost Done • Choose DOF, OK • And Then…. . . CFD Analysis with ANSYS/FLOTRAN • -Plot Path Item on Graph Training Manual 001312 30 Nov 1999 2 -47

Path Plot of the Outlet Velocity! Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30

Path Plot of the Outlet Velocity! Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -48

Some Discussion Training Manual – Plot. Ctrls>Style>Colors>Graphs • Modify the plot controls as needed

Some Discussion Training Manual – Plot. Ctrls>Style>Colors>Graphs • Modify the plot controls as needed with Utility Menu – Plot. Ctrls>Style>Graphs • Result – Fully developed flow would show the outlet velocity profile as a perfect parabola – Therefore, the problem domain could be lengthened to provide room for more flow development – Check the Mass Balance CFD Analysis with ANSYS/FLOTRAN • Modify the line colors as needed with the Utility Menu 001312 30 Nov 1999 2 -49

The Print File Training Manual • List > Files> Other> (choose jobname. pfl file)

The Print File Training Manual • List > Files> Other> (choose jobname. pfl file) • Scan to the bottom • Mass balance looks good!!! • (If you had forgotten to put a No-Slip Boundary condition somewhere, there would be another outlet listed…. ) CFD Analysis with ANSYS/FLOTRAN • Use the Utility Menu to Look at the bottom of the jobname. pfl file 001312 30 Nov 1999 2 -50

Massless Particle traces Training Manual • For a steady state, perfectly converged problem on

Massless Particle traces Training Manual • For a steady state, perfectly converged problem on a perfect mesh, the streamlines and particle trace plots would be identical. • Procedure: Plot Results>Flow Traces – Define trace points with PICKER – Plot Flow Traces • Optionally color code trace with • the value of a DOF CFD Analysis with ANSYS/FLOTRAN • Particle traces are based on the velocity field, not the stream function. 001312 30 Nov 1999 2 -51

Trace Points Training Manual – Ensure, for 3 D models, that the WP is

Trace Points Training Manual – Ensure, for 3 D models, that the WP is correctly located! • The resolution of the trace point location is controlled by the currently set Snap Increment (Working plane controls) CFD Analysis with ANSYS/FLOTRAN • The points defined on the Working Plane 001312 30 Nov 1999 2 -52

Particle Trace • Note Maximum number of loops allowd • OK CFD Analysis with

Particle Trace • Note Maximum number of loops allowd • OK CFD Analysis with ANSYS/FLOTRAN • Color Code According to PRES (or something else!) Training Manual 001312 30 Nov 1999 2 -53

Particle Trace CFD Analysis with ANSYS/FLOTRAN • The maximum number of loops is exceeded

Particle Trace CFD Analysis with ANSYS/FLOTRAN • The maximum number of loops is exceeded in the recirculation region. Close the box Training Manual 001312 30 Nov 1999 2 -54

New Analysis Training Manual – This makes the Reynolds Number ~8500 • Solve the

New Analysis Training Manual – This makes the Reynolds Number ~8500 • Solve the problem – Very Shortly you will get a message that either the solution has diverged or that a negative value has been encountered in the coefficient matrix main diagonal. • This is because the flow is now in the turbulence regime and a laminar solution will be unstable. • So activate the turbulence model and again solve. CFD Analysis with ANSYS/FLOTRAN • Increase the velocity from 10 to 200 (no other changes) 001312 30 Nov 1999 2 -55

FLOTRAN Solution Options • SOLVE CFD Analysis with ANSYS/FLOTRAN • Activate Turbulence with Scroll

FLOTRAN Solution Options • SOLVE CFD Analysis with ANSYS/FLOTRAN • Activate Turbulence with Scroll Down Menu Option, OK Training Manual 001312 30 Nov 1999 2 -56

Convergence Monitors Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -57

Convergence Monitors Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -57

Turbulent Flow Results Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2

Turbulent Flow Results Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -58

Discussion Training Manual • Consider Bernoulli’s equation and note that in our new, higher

Discussion Training Manual • Consider Bernoulli’s equation and note that in our new, higher velocity problem the relative importance of the viscosity has decreased. – The recoverable pressure due to the velocity change now dramatically outweighs the viscous losses. CFD Analysis with ANSYS/FLOTRAN • Note that the maximum value of pressure is no longer at the inlet. It has moved to the outlet !!! 001312 30 Nov 1999 2 -59

New Outlet Velocity Profile Training Manual CFD Analysis with ANSYS/FLOTRAN • A Fully developed

New Outlet Velocity Profile Training Manual CFD Analysis with ANSYS/FLOTRAN • A Fully developed flow would have the maximum value in the center. This implies we should make the problem domain longer…. 001312 30 Nov 1999 2 -60

Another New Analysis - Extend the Problem – Add another rectangle to the outlet

Another New Analysis - Extend the Problem – Add another rectangle to the outlet • Try 15 additional inches • Remember to Merge Keypoints – Revise boundary conditions • Delete old pressure boundary • Pressure on new boundary • Walls CFD Analysis with ANSYS/FLOTRAN • Outline of the steps required Training Manual 001312 30 Nov 1999 2 -61

New Geometry Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -62

New Geometry Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -62

Completing the New Geometry Training Manual As expected, the meshed line is kept CFD

Completing the New Geometry Training Manual As expected, the meshed line is kept CFD Analysis with ANSYS/FLOTRAN • Preprocessor>Numbering Ctrls>Merge Items> Keypoints 001312 30 Nov 1999 2 -63

New Boundary Conditions CFD Analysis with ANSYS/FLOTRAN • Preprocessor>Loads>Delete> Training Manual 001312 30 Nov

New Boundary Conditions CFD Analysis with ANSYS/FLOTRAN • Preprocessor>Loads>Delete> Training Manual 001312 30 Nov 1999 2 -64

New Boundary Conditions Training Manual • Assign Zero pressure to the outlet line as

New Boundary Conditions Training Manual • Assign Zero pressure to the outlet line as done previously CFD Analysis with ANSYS/FLOTRAN • Add the walls as done previously 001312 30 Nov 1999 2 -65

Mesh the New Outlet Area • PICKER asks for the line to be copied

Mesh the New Outlet Area • PICKER asks for the line to be copied from (pick and. OK) and then the line to be copied to (pick and OK). CFD Analysis with ANSYS/FLOTRAN • Use the Mesh tool to copy the transverse direction assignment to the new outlet boundary. Training Manual 001312 30 Nov 1999 2 -66

Set Divisions Along Outlet CFD Analysis with ANSYS/FLOTRAN • Flip the line after setting

Set Divisions Along Outlet CFD Analysis with ANSYS/FLOTRAN • Flip the line after setting (when necessary) Training Manual • Then Mesh the New Area as in previous fashion 001312 30 Nov 1999 2 -67

The Mesh Training Manual • The complete mesh with the symbols turned off. .

The Mesh Training Manual • The complete mesh with the symbols turned off. . CFD Analysis with ANSYS/FLOTRAN • Note that the symbols shown are the previously transferred Nodal Boundary Conditions. The solid model boundary conditions don’t show up on an element plot. 001312 30 Nov 1999 2 -68

Execute Training Manual – This occurs because the number of nodes and elements in

Execute Training Manual – This occurs because the number of nodes and elements in the case has changed. – Other files such as the jobname. pfl are appended to, even though this is a new analysis CFD Analysis with ANSYS/FLOTRAN • Note that if you have not changed the jobname, FLOTRAN will provide a notice to the effect that it has renamed the old results file to jobname. rfo 001312 30 Nov 1999 2 -69

Convergence Monitors Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -70

Convergence Monitors Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -70

Convergence Monitors - more Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999

Convergence Monitors - more Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -71

Results Training Manual • Note that the pressure drop, once the flow has recovered,

Results Training Manual • Note that the pressure drop, once the flow has recovered, is very small. • We expect a good outlet velocity profile. CFD Analysis with ANSYS/FLOTRAN • Two representations of pressure, the second in the vector mode with 128 contours. 001312 30 Nov 1999 2 -72

Recirculation Region CFD Analysis with ANSYS/FLOTRAN • The recirculation region is captured despite the

Recirculation Region CFD Analysis with ANSYS/FLOTRAN • The recirculation region is captured despite the relatively coarse mesh. Training Manual 001312 30 Nov 1999 2 -73

Benefits of Extension Training Manual Old Outlet CFD Analysis with ANSYS/FLOTRAN • The lines

Benefits of Extension Training Manual Old Outlet CFD Analysis with ANSYS/FLOTRAN • The lines are superimposed onto the new velocity vector plot. It is clear that the flow is continuing to develop past the original boundary of the problem. 001312 30 Nov 1999 2 -74

Outlet Velocity Profile Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2

Outlet Velocity Profile Training Manual CFD Analysis with ANSYS/FLOTRAN 001312 30 Nov 1999 2 -75

Final Check of Transverse Velocity Training Manual End of Problem! CFD Analysis with ANSYS/FLOTRAN

Final Check of Transverse Velocity Training Manual End of Problem! CFD Analysis with ANSYS/FLOTRAN • The flow is very close to fully developed. The following plot of the transverse velocities at the outlet provides a measure of how close it is. Note the scale. The maximum transverse velocity is 0. 11. 001312 30 Nov 1999 2 -76