Three dimensional, transonic, turbulent flow over the ONERA M6 wing.

Freestream Conditions

Grid

1. To start UPMS type upms at the command prompt and hit RETURN (If this does not work, check path or consult your system administrator). After a few seconds UPMS will start and presents a single comprehensive view of modeling and simulation process as shown in Fig. 1

Fig. 1

2. The next step is to select the directory in which the grid file resides. To do this, from File pull down menu click Preferences and select Working Directory. Upon doing this, it will result in window similar to the one shown in Fig. 2.

Note: Unless, it is specifically mentioned, for selection and accepting (e.g. click OK), use always LEFT button of Mouse.

Fig. 2

You can navigate (from Look in) to select the working directory. It is important to note that when the user selects a particular directory, it gets highlighted. Now you must click Select button; otherwise the desired directory will not be selected (double click will not work).

3. From File pull down menu, select New Project if you are starting a new project, which is the case for this tutorial problem (Fig. 3). For an existing project, select Load Project. Upon selecting New Project, this will prompt for Project Name, Grid File as well as CFD Application (PAB3D or CFL3D or TLNS3D). Type the name of the project name and the grid file name in the respective text boxes; also select the desired code from CFD Application. The grid file name can also be selected by double clicking the text box corresponding to Grid File; this will result in a window where all the files residing in the working directory can be seen from which grid file can be selected.

For our tutorial problem enter as shown below and click OK. Make sure to have the grid file in your working directory.

Fig. 3

Click OK. A window, which gives the definition of blocks, will be displayed (Fig. 4)

Fig. 4

You have the option of selecting the Blocks, adding or deleting Face Cuts. For this tutorial problem, take default values and click OK, which results in two windows as shown in Figs. 5 and 6.

Fig. 5

Fig. 6

Fig. 5 shows important information about the boundary conditions for the problem chosen for this tutorial problem. It gives the total number of boundary conditions UPMS could recognize from the grid. The total number of boundary conditions is divided into 3 types, General, Undefined, and Patched. These BC’s will be explained in more detail later in this tutorial. Click OK.

You should take a note of GUI shown in Fig. 6. The title bar shows current project title and the status bar shows the name of the current working directory and the current application mode (solver mode). The user has to provide all-important information such as Flow BC, Flow, Solver, Viscosity, Boundary conditions through this GUI. The default parameters in Solver and Viscosity work for many problems.

The user can change the look (Metal, Windows, or Motif) of UPMS Window Manger. Metal is the default option (See Fig.1). This can be done by selecting Windows Manager from Preferences pull down menu. This gives you an option to choose (Fig. 7).

Fig. 7

Fig. 8 (Windows) Fig. 9 (Motif)

Before going further, it is useful to see the image of geometry. Clicking the Active Display check box in Tools pull down menu will do it. A warning message pops up, notifying the user that it is not possible to use New, Load or Import from File menu. Click Yes to continue. After few seconds, an image will appear on left panel of UPMS window (Fig. 10).

Fig. 10

You can zoom, reduce, translate and rotate the image. The image can be zoomed or reduced by moving mouse down and up respectively while holding the middle button pressed (in case of mouse with only two buttons, use left button while holding Alt). To translate the image, move the mouse in the desired direction while holding down the right button of mouse. To rotate image, move the mouse in the desired direction while holding down the left mouse button.

You can change the speed of translation and zoom (in/out) by changing values for Translation and Zoom parameters available in Model Parameters window. To do this, first select Model Parameters from Tools pull down menu (Fig. 11)

Fig. 11

Speed will be changed by the factor selected i.e. after selecting the parameter, current speed will be equal to the speed before setting the value for Zoom or Translation multiplied by the factor selected.

Select Flow BC option from UPMS Windows Manger (Fig. 12)

Fig. 12

Here you have the provision to provide flow boundary conditions. You can also divide a block into sub-domains, and can input specific flow condition for each sub-domain. The user can also specify values in either English or SI units. Variable type can be Static, Total or based on Reynolds number.

Flow conditions for each block can be specified if the flow conditions are different. If all blocks need to be specified with same flow conditions, use the Select All option.

For this tutorial problem, enter the following values as shown in Fig. 13 and click Save Block Options

Fig. 13

Select Flow option (Fig. 14)

Fig. 14

The flow option is provided to input initial conditions. This can be done by clicking Copy from BC. However, this option is not yet implemented at present, therefore you must key in the values. These interface features are also available in the Flow BC interface.

For this tutorial problem enter the values that were used in Flow BC and click Save Block Options. Make sure all the blocks were selected before entering the values.

Select Solver option (Fig. 15).

Fig. 15

From Global options, you can select CFL Scheme from the CFL Scheme pull down menu. You can also set Global Iterations and number of iterations. For example if you set 10 for Global iterations and 10 for number of iterations, the total number of iterations will be 100. You can also select the factorization scheme.

Again, for a wide variety of applications, the values in this interface are optimal and should work to give sufficiently accurate results. You are warned against changing these values unless you understand the physics of the problem well enough to change them.

To change Flow Type, click Set Preset. This pops up a Solver Presets window (Fig. 16) from which you can select type of flow

Fig. 16

As shown in fig. 16, you can choose any flow type depending on the problem. For example, choosing Shear Layer and clicking Display, one should get (Fig. 17).

Fig. 17

Note that some parameters change corresponding to the flow type selected. Also, you must click Save Block Options to save the flow type. As can be seen from right panel of Fig. 17, this interface provides you a choice to select specific block or any number of blocks for which you want to apply parameters. Multiple selections can be achieved by clicking the desired blocks while holding CTRL key. Select Opposite option can be used to select every block except the highlighted one.

You also have the option to create your own flow type and can give any name. To do this you should select User 1 to 5 from Solver Presets and click Display. A text box will be created where you can change the name ‘User1’ to any desired name. You can input all the parameter in main UPMS panel. Click Save to save the settings; all the values will be saved in User 1 or the selected name.

You can choose the integration scheme from the Integration pull down menu, which could be PNS, Time Dependent, and SMS.

You can also choose Jacobian (Fig. 18)

Fig. 18

Three flux schemes are available (Fig. 19).

Fig. 19

However, it is recommended that the default scheme (Roe) be used, as it works for a wide variety of applications.

Grid Sequencing Level provides you with an option to perform computations on coarse or fine grids. You can perform computations on a course grid initially by setting I=j=k=4 and later can make it finer by i, j, k values of either 2 or 1.

Limiter and Spatial accuracy can be set in any direction (i, j, k), and for a specific block or set of blocks.

You must once again click Save Block Options to save the changed data.

For this tutorial problem, select default values in Solver option

Upon selecting Viscosity option, you should see as shown in Fig. 20. For a wide variety of applications, the values in this interface are optimal and should work to give sufficiently accurate results. You are warned against changing these values unless you understand the physics of the problem well enough to change them.

Fig. 20

As can be seen from right panel of Fig. 20, this interface provides you a choice to select specific block or any number of blocks for which he/she wants to apply viscosity parameters. Multiple selections can be achieved by clicking desired block while holding the CTRL key. Select Opposite option can be used to select every block except the highlighted one.

To change Flow Type, click Set Preset. This pops up a Viscosity Presets window (Fig. 21) from which you can select type of flow.

Fig. 21

As shown in fig. 21, you can choose any flow type depending on the physics of problem. For example, choosing Separated Boundary Layer and clicking Display, one should get (Fig. 22)

Fig. 22

Note that some turbulence parameters change corresponding to the flow type selected. Also, you must click Save Block Options to save the flow type. As in the case of Viscosity, you also have the option to create your own flow type and can give it any name. To do this you should select User1 (or up to User5) from viscosity presets and click display. You can input all the parameters in the main UPMS panel. You can change the name from User 1 to any desired name and click Save.

You should choose Diffusion terms depending on the physics of problem. A large number of options are available to you (inviscid to Full Navier Stokes). See fig. 23.

Fig. 23

Warning: you are advised against using Full Navier Stokes unless the grid used is large enough for this option. Many times, dependent variables change only in two directions. For a wide variety of problems, it is recommended not to use Full Navier Stokes.

You should choose Viscous Model (Turbulence Model) depending on the physics of problem. Again, a large number of models are available for you to choose. See fig. 24.

Fig. 24

Full discussion on Turbulence parameters is provided in the User’s manual.

For this tutorial problem, select default values in Viscosity option

Upon selecting Boundary Conditions option, you should see the GUI as shown in Fig. 25

Fig. 25

Warning: Before specifying boundary conditions, you must be aware that the AutoGrid option which was used to read the grid may not identify all faces in correct fashion. It might add some cuts that might not be needed, or it may not cover a face/cut in the desired fashion. You must check and specify all the boundary conditions very carefully.

By default, Block 1 and IMin will be selected at the start. Now let us start specifying all BC’s for the tutorial problem. You can specify BC’s by selecting any block.

Start with Face (IMin) of Block 1. You need to give the range of I, J and K values (if the values are incorrect) and specify boundary condition.

The values of J1 and J2 are correct; no need to change them. However the value of K1 is wrong. It should start from 1. The boundary condition for this face is Extrapolation, which can be selected from the pull down menu at the bottom of the right side panel. Once you change the values, the GUI should look as shown in Fig. 26.

Fig. 26

This process should be completed for all other remaining faces of Block 1. From the Face pull down menu, select IMax. If UPMS selected J and K values as well as boundary condition correctly, you don’t need to change anything, which is the case here. The GUI should appear as shown in Fig. 27.

Fig. 27.

Notice, upon changing face to IMax, Face IMin of Block 2 in Destination sub-panel became focused and the user will be able to change it if there is any error. It tells you that the IMax face of Block 1 and IMin face Block 2 are falling on the same plane. Changes to destination sub-panel are only possible if you are dealing with a face that is common to two blocks. This is true for our tutorial problem and does not need any correction. Also notice that the Boundary Condition for this face is Use Adjacent face, which is also correct. As can be seen from Fig. 26 and 27, for convenience, color-coding is used for boundary conditions.

Block 1, select JMin face. The resulting K and I limits, as well as BC are correct and don’t require change. Block information in Destination in sub-panel is also correct.

Warning: you must make sure all automatically generated information is correct. You might need to closely examine the geometry by using options such as translation, rotation and zoom to ensure the correctness and make changes if necessary. You can also use Configure View from Tools pull down menu, to see different blocks. For example to view Block 1, select Configure View from the Tools pull down menu. This will result in the dialog popping up as shown in Fig. 28.

Fig. 28

This dialog will show the information on blocks. Highlight block1 and click Redraw. You should get the GUI as shown in Fig. 29.

Fig. 29

For Multiple selections, highlight the desired block by holding CTRL and clicking left button of mouse. To deselect, click the highlighted blocking while holding CTRL.

Block 1, select JMax face. Resulting K and I limits are correct, but the boundary condition is not defined. Select Farfield for this tutorial problem. (Fig. 30)

Fig. 30

Notice that JMax face of Blocks 2, 3 and 4 have the same boundary condition. Examine this by selecting Blocks 2, 3 and 4. Multiple selections of blocks can be achieved by clicking blocks to highlight while holding CTRL. This way one can apply boundary conditions very quickly. Let’s do it now.

Select Blocks 2, 3, and 4 with JMax face. Change BC to Farfield. And click Save Options (Fig. 31)

Fig. 31

Now, one can examine the Boundary Condition for each block. You should see the GUI as shown in Fig. 32 if you select Block 2 and JMax face.

Fig. 32

On Block 1, select KMin face. The resulting BC is correct, but the limits for I are incorrect. Also notice the Boundary Condition of KMin face for all blocks is the same. However, BC cannot be applied to KMin surface of all blocks at the same time due to incorrect I limits. It may be noted, after selecting more than a block, it is not possible to change the I, J and K limits. However values of I and J can be corrected first block by block, then one can specify BC on KMin surface of all the blocks at the same time.

Now set values for I. No need to change J values, as they are correct.

Block 1, I1 = 1 and I2 = 24

Block 2 (No changes)

Block 3, I1 = 1 and I2 = 72

Block 4, I1 = 1 and I2 = 24

Now select KMin surface of all the blocks at the same time. Since BC (General Symmetry) is correct, click Save Options.

On Block 1, select JMin face. Resulting K and I limits as well as BC are correct and hence no need change; Block information in Destination in sub-panel is also correct.

The resulting I and J limits as well as BC are correct and hence don’t need to be changed. The block information in Destination sub-panel is also correct.

Block 2, select IMin face. All parameters are correct.

Block 2, select IMax face. All parameters are correct

Block 2, select JMin face. Resulting BC is incorrect. Change BC to No Slip Wall.

Block 2, select JMax face (BC defined already).

Block 2, select KMin face (BC defined already).

Block 2, select KMax face. All parameters are correct.

Block 3, select IMin face. All parameters are correct.

Block 3, select IMax face. All parameters are correct.

Block 3, select JMin face. The resulting BC as well as I range is incorrect. Change BC to No Slip Wall. Set values for I1 to 1 and I2 to 72.

Block 3, select JMax face (BC defined already).

Block 3, select KMin face (BC defined already).

Block 3, select KMax face. All parameters are correct.

Block 4, select IMin face. All parameters are correct.

Block 4, select IMax face. Range for K as well as BC is incorrect. Set K1 to 1 and K2 to 32. Change BC to Extrapolation.

Block 4, select JMin face. All parameters are correct.

Block 4, select JMax face (BC defined already).

Block 4, select KMin face (BC defined already).

Block 4, select KMax face. All parameters are correct.

You must examine the Boundary Conditions again to check if there are still any undefined surfaces. Do this by selecting Boundary Conditions from Tools pull down menu. This will give you the Boundary Conditions window as shown in Fig. 33.

Fig. 33.

This window gives complete information on boundary conditions. In this case, UPMS recognized 27 boundary conditions (Warning: they are not necessarily correct). They are divided into Unresolved (0), Undefined (1), Patched (14), General (10), Unmatched Pairs and Open Faces. The numbers given in the parenthesis are relevant only to this tutorial problem. However, we are supposed to get only 24 faces unless there are additional cuts, which is the case with the present tutorial problem. Therefore care should be taken to identify any unwanted surfaces/cuts and these must be deleted. Also, all the boundary conditions that show up in red color must be corrected. E.g. in this tutorial problem, one undefined BC must be corrected. To view this BC, click Undefined. (Fig. 34)

Fig. 34

You can also arrange the columns by dragging them (press left button of mouse during this operation) and placing them wherever you wish.

There is one surface (JMin) of Block 3, which is not defined. By checking display box, one can view this surface. It also tells us that there is a cut (defined by 2). However, we do not need this cut and it can be deleted as follows

Boundary Conditions -> Select Block 3 -> JMin face

Face Cuts -> Select 2

Click Delete (To delete cut 2)

This action deletes the cut; it also removes Undefined (becomes unfocussed) in the Boundary Conditions window

Now let us examine other boundary conditions. Click patched to get interface as shown in Fig. 35.

Fig. 35

By examining the Fig. 35, you will be able to recognize that there are the following unwanted cuts

By double clicking on any row in Patched Condition window, the information corresponding to this cut can be seen on main UPMS panel. For example, after double clicking Block 3, KMin, 2, Use Adjacent Face, you should be able to see the information as shown in Fig. 35.

Fig. 35.

Looking at Fig. 35, we can clearly visualize that this cut is not necessary. To delete this cut, click Delete (in Face Cuts sub-panel). In a similar way the other cut (Block 4, KMin, 2, Use Adjacent Face) can also be deleted. You might have to close and open Boundary Conditions (available from Tools pull down menu) to refresh.

Note: Boundary conditions (available through the Tools pull down menu) is very useful for checking accuracy as well as accounting for all the surfaces. After specifying BC’s, you must run through all the boundary conditions to ensure accuracy.

For our tutorial problem, patched conditions look as shown in Fig. 36

Fig. 36

General Conditions are divided broadly into three types again; Clicking General will give window as shown in Fig. 37

Fig. 37

One can see Flow, Symmetry and Wall conditions by clicking one of them. For example, if you click Symmetry Conditions, the interface for this tutorial problem should look as shown in Fig. 37

Fig. 37

One can view the BC specified to each face by checking Display box.

Patched face corresponds to a face common to two adjacent blocks.