File name: gridhelp

Mouse click grid generation has the following capabilities:

• Generating Cartesian/Polar grid
• Generating BFC grid
• Setting unsteady time distribution
• Setting initial field
• Allowing three dimensional view control
• Providing Access to HELP
• Writing complete PIL commands for time and grid setting

The file can be accessed from both POLIS and the VIEW command.

Menu buttons:

(D) means this button has a double click feature

Group 1: General buttons:

STEADY/UNSTEADY	Entry to time dependence setting
CHAM LOGO	Access to HELP
OK	Exit, plot and save data

Group 2: View control buttons:

VIEW	Change view direction by mouse dragging
UP	Change up direction by mouse dragging
XYZ	Set view direction to nearest axis direction
MOVE	Move picture in window by mouse dragging
ZOOM	Enlarge or reduce picture by mouse dragging
DEPTH	Change view depth by mouse dragging
NORMAL	Set view parameters to see whole picture
RESET	Change view and display parameters by data

Group 3: Time dependence setting buttons:

STEADY/UNSTEADY	Switch between steady and unsteady
TFIRST	Set the starting time
LSTEP	Set the time steps
TLAST-TFIRST	Set the total duration
CUT REGIONS	(D) Cut into more regions
MERGE REGIONS	Merge neighbouring regions
MODIFY REGIONS	Set distributions in regions
OK	Confirm and end time setting

Group 4: Non-BFC grid generation buttons:

GRID: CARTES	Show grid type and switch to Polar
GO TO BFC	Start BFC grid setting from Cartesian
DIMENSION	Set number of cells in each direction
DOMAIN	(D) Set size of the whole solution domain
NEW OBJECT	(D) Create a new object
MODIFY OBJECT	(D) Modify an object
DELETE OBJECT	Delete an object
GROUP MOVE	(D) Move a group of objects
GROUP COPY	(D) Copy a group of objects
X REGIONS	Set X regions
Y REGIONS	Set Y regions
Z REGIONS	Set Z regions
INITIAL FIELD	Enter the initial field setting
GRID: POLAR	Show grid type and switch to Cartesian
GO TO BFC	Start BFC grid setting from Polar
RINNER	Modify RINNER for Polar grid

Group 5: Initial field setting buttons:

INIT FIELD OFF	Enter the initial field setting
INIT FIELD ON	Quit from initial field setting
BACKGROUND	Set background value
VALUE	Set value for the current colour
COLOUR	Set the current colour
SET	Set the field using current colour
OK	End the initial field setting

Group 6: BFC grid generation buttons:

GRID: BFC	Show grid type and switch to Cartesian/polar
GO TO CAR/POL	Show and go back to non-BFC grid type
DIMENSION	Set grid dimension
NEW POINTS	(D) Create new points
MODIFY POINTS	(D) Modify existing points
NEW LINES	Join two points for a straight line
NEW ARCS	Select three points to define an arc line
NEW CURVES	Select at least two points to form a curve line
MODIFY LINES	Modify existing lines
NEW FRAMES	Define new frames
MATCH GRID	Match grid meshes to frames
COPY....	Perform COPY/TRANSFER/BLOCK operations
DELETE	Delete POINTS/LINES/FRAMES or clear all

Detailed descriptions for all buttons

STEADY/UNSTEADY Entry to time dependence setting

Click on this option to display a time dependence setting menu where unsteady status can be switched on or off. In an unsteady case, time distribution can be specified by mouse click or data input.

CHAM logo Access to HELP

Click on the CHAM logo to enter the BROWSER sub-system for help information.

OK Exit, plot and save data

Click on this option to show a sub-menu where three options are displayed:

CONTINUE for not quitting yet
PLOT for saving the display in plot file
END for quitting and saving data

VIEW Change view direction by mouse dragging

Once this option is selected, move the cursor inside the drawing window, press down and hold the left mouse button and move the cursor up/down/left/right to change view direction and then release the mouse button. View and up direction values are displayed on top of the screen. Move the cursor outside the drawing window and click to end the operation. A button can be selected by the click for next action.

UP Change up direction by mouse dragging

Once this option is selected, move the cursor inside the drawing window, press down and hold the left mouse button and move the cursor round the centre of the drawing window to change up direction and then release the mouse button. Up direction values are displayed on top of the screen. Move the cursor outside the drawing window and click to end the operation. A button can be selected by the click for next action.

XYZ Set view direction to nearest axis direction

When this is selected, the view and up directions will be adjusted automatically to their nearest axis directions.

MOVE Move picture in window by mouse dragging

Once this option is selected, move the cursor inside the drawing window, press down and hold the left mouse button and move the cursor in any direction and then release the mouse button. The picture will follow the cursor and be displayed at the new position. The view centre coordinates are displayed on top of the screen. Move the cursor outside the drawing window and click to end the operation. A button can be selected by the click for next action.

ZOOM Enlarge or reduce picture by mouse dragging

Once this option is selected, move the cursor inside the drawing window, press down and hold the left mouse button and move the cursor up and down and then release the mouse button. Moving up means pushing the picture away, so the picture gets smaller; moving down makes it larger. The view size data is displayed on top of the screen. Move the cursor outside the drawing window and click to end the operation. A button can be selected by the click for next action.

DEPTH Change view depth by mouse dragging

Once this option is selected, move the cursor inside the drawing window, press down and hold the left mouse button and move the cursor up and down and then release the mouse button. A top view is displayed and it follows the cursor to move along the view direction. The view centre point is changed and the data is displayed on top of the screen. Move the cursor outside the drawing window and click to end the operation. A button can be selected by the click for next action.

NORMAL Set view parameters to see whole picture

This will recalculate the view centre and view size according to the current grid setting. The new view centre and view size are used to display the picture at the centre of the screen.

RESET Change view and display parameters by data

A sub-menu of three options are displayed:

VIEW CONTROL for resetting view controls
DISPLAY CONTROL for resetting display controls
CANCEL for not resetting anything

If VIEW CONTROL is selected, a further menu will be displayed. It allows for changing view direction, up direction, view centre, view size and axis length. Note that view direction and up direction should not be set to zero length and they should not be exactly in the same or opposite directions.

Setting axis length to zero will turn off the display of axis.

If DISPLAY CONTROL is selected, a menu of many options is displayed. It allows control on what is displayed in the drawing window.

STEADY/UNSTEADY Switch between steady and unsteady

If it is steady, this option will make it unsteady, and unsteady options will be displayed as well as a graphic display of the time distribution.

If it is unsteady, this option will switch off unsteady setting and make it steady.

TFIRST Set the starting time

The starting time can be changed by selecting this option and typing in the new value.

LSTEP Set the time steps

The number of time steps can be changed by selecting this option and typing in the new value.

TLAST-TFIRST Set the total duration

The total duration can be changed by selecting this option and typing in the new value.

CUT REGIONS (D) Cut into more regions

After a single click, move the cursor into the time display window and point to a place where a time region boundary is to be located and click.

After a double click, the new region boundary location can be type in.

MERGE REGIONS Merge neighbouring regions

Move the cursor close to a region boundary and click once to remove it. The two neighbouring regions are merged together.

MODIFY REGIONS Set distributions in regions

Move the cursor into a region of time distribution and click; a menu appears to allow changing cell and power in the region.

OK Confirm and end time setting

Select this option to end the time distribution setting.

GRID: CARTES Show grid type and switch to Polar

This option shows that the grid type is Cartesian. Click it to change to polar grid.

GO TO BFC Start BFC grid setting from Cartesian

This is the place to start the BFC grid generation. The starting grid is exactly the current Cartesian grid and it keeps all the regions created by possible objects in the solution domain.

DIMENSION Set number of cells in each direction

This allows resetting of the total number cells in each direction. Grid meshes are evenly distributed in regions which are generated automatically by objects.

A tolerance value can be set here for use in matching grid meshes.

DOMAIN (D) Set size of the whole solution domain

Mouse dragging is used here to set the size of the whole solution domain.

NEW OBJECT (D) Create a new object

As soon as this option is selected, a new object of the same size as the solution domain is created. After a single click, the new object size and location can be changed by mouse dragging. After a double click, the name, size and location of the new object can be changed by entering data.

MODIFY OBJECT (D) Modify an object

Select an object and then: if the option is selected by a single click, you can use mouse dragging to change the size and the location of the object; if the option is selected by a double click, a menu allows the changing of the name, size and location of the object by specifying data.

DELETE OBJECT Delete an object

Move the cursor close to an object and click; the object is deleted.

GROUP MOVE (D) Move a group of objects

Select a group of objects; finish by clicking out of the window. If the option is selected by single clicking, the group of objects can be moved by mouse dragging. If the option is selected by double clicking, the new location of the group of objects can be set by specifying data.

GROUP COPY (D) Copy a group of objects

Select a group of objects; finish by clicking out of the window. At the time the selection finishes, the group of objects are duplicated at their original location. According to single clicking or double clicking, the duplicate group can be moved by either mouse dragging or by specifying data.

X REGIONS Set X regions

Select an X region and a menu appears to allow the number of cells and distribution power in the region to be changed.

Y REGIONS Set Y regions

See X REGIONS

Z REGIONS Set Z regions

See X REGIONS

INITIAL FIELD Enter the initial field setting

GRID: POLAR Show grid type and switch to Cartesian

This option shows that the grid type is polar. Click it to change to a Cartesian grid.

Except the setting of RINNER, Polar grid can only be modified by going to Cartesian mode and modifying the grid and coming back to polar mode.

GO TO BFC Start BFC grid setting from Polar

This is the place to start the BFC grid generation. The starting grid is exactly the current polar grid and it keeps all the regions created by possible objects in the solution domain.

RINNER Modify RINNER for Polar grid

This allows RINNER to be modified by typing in the new value.

INIT FIELD OFF Enter the initial field setting

Turn on the initial field setting by asking for a variable name. The name should be up to four characters long.

INIT FIELD ON Quit from initial field setting

Turn off the initial field setting and save data in a file with a name starting 'vf' followed by the variable name.

BACKGROUND Set background value

The background value of the initial field can be set by entering a value at this option.

VALUE Set value for the current colour

The value of the current working colour can be set with this option.

COLOUR Set the current colour

Change the working colour by clicking on this option. The working colour index will change between 1 and 14.

SET Set the field using current colour

Use mouse dragging to set the current working colour on blocks of cells.

OK End the initial field setting

End the initial field setting without closing the data file. The initial field stays on screen. The next time the initial field setting is entered, you can continue editing it.

GRID: BFC Show grid type and switch to Cartesian/polar

This option shows that the grid type is BFC. Click it to change back to its non-BFC starting grid.

GO TO CAR/POL Show and go back to non-BFC grid type

This option shows whether the BFC grid is started from a Cartesian grid or polar grid. Click on this option to go back to the non-BFC starting grid.

DIMENSION Set grid dimension

Set grid dimension and default grid size. This will set up the initial grid with Cartesian-like uniform distributions.

NEW POINTS (D) Create new points

After single clicking on this option, points can be created by mouse dragging. Move the cursor inside the drawing window, press down and hold the left mouse button and move the cursor along axis directions on the screen and then release the mouse button. The point coordinates are displayed on top of the screen. Move the cursor outside the drawing window and click to end the operation. A button can be selected by the click for next action.

When the left mouse button is pressed, the initial point position is on the view plane which goes across the view centre. It is advisable to check and reset the view depth or view centre before setting new points.

When moving the cursor along axis directions after the left mouse button is pressed, the longer the axis shows on the screen, the easier the coordinate on that direction can change. One coordinate can not change at all if that direction is very close to the view direction.

After double clicking on this option, points can be created by typing in the coordinates. Select CANCEL in the menu to end the session.

MODIFY POINTS (D) Modify existing points

After a single click on this option, points can be moved by mouse dragging. Move the cursor inside the drawing window, press down and hold the left mouse button and move the cursor along axis directions on the screen and then release the mouse button. A point is selected if it is nearest to the cursor position when the mouse button is pressed. The new coordinates are displayed on top of the screen. Move the cursor outside the drawing window and click to end the operation. A button can be selected by the click for next action.

After a double click on this option, a point can be picked and a menu is displayed to allow changing the name and coordinates of the point. Move the cursor outside the drawing window and click to end the operation. A button can be selected by the click for next action.

NEW LINES Join two points for a straight line

Select two points by moving the cursor near the first point and clicking then moving the cursor near the second point and clicking. As soon as the two points have been selected, a new line with one cell is created.

You cannot create a new line to join two points which have already been used as the starting and ending points of another line.

To quit from this mode, move the cursor out of the black window and click once. If the cursor is on a button, the button is also picked.

NEW ARCS Select three point to define an arc line

Select three points in the order: starting point, middle point and ending point. An arc line with one cell is created.

NEW CURVES Select at least two points to form a curve line

Select a number of points to generate a curve line. Leave up to two points for setting boundary conditions. When all the points on the curve (not the points for boundary conditions) have been selected, move the cursor out of the window and click once.

If no boundary condition is required, keep the cursor out and click again.

If at least one boundary condition is to be set, move the cursor back in the window.

To set a boundary condition at starting point, select another point. The direction and length from the starting point to the selected point will decide the starting boundary condition. If no condition is required, select the starting point.

To set a boundary condition at ending point, select another point. The direction and length from the selected point to the ending point will decide the ending boundary condition. If no condition is required, select the ending point. After all above operations, a new curve line is created.

To quit from this mode, move the cursor out of the black window and click once. If the cursor is on a button, the button is also picked.

You have to complete the curve line before quitting, but you can delete it if it is not wanted.

MODIFY LINES Modify existing lines

Select a line by moving the cursor near the name of the line and click once. A menu appears with the current setting of line name, number of cells and distribution power.

NEW FRAMES Define new frames

Start from one corner point, select all the line-connecting points (not points used inside arc and curve lines) until reaching the starting point again. The starting point will automatically become the first corner point. You still need to select the remaining three corner points unless they can be decided by what are available.

If numbers of cells at boundaries do not match, the frame name is displayed with at least one negative number; otherwise, the correct numbers are displayed.

MATCH GRID Match grid meshes to frames

Once this option is selected, you need to pick a frame for matching. When a frame is picked, you can see a panel of various parameters. Make changes and select 'OK'.

To unmatch a frame, set the corner index to '0'.

One option in the match panel is 'Grid Check'. You can select it to switch on or off the grid orthogonality checking on the matched grid.

A frame-in-frame feature has been built in for easy setting of the grid, especially in the situation that internal blockages exist. The internal frame must be defined first and the matching of the outer frame needs to have the Laplace solver switched on.

COPY.... Perform COPY/TRANSFER/BLOCK operations

This option allows setting up and editing commands for performing COPY/TRANSFER/BLOCK operations.

Follow instructions on the screen to insert/modify/ delete command lines. Each line may be either a COPY, TRANSFER or BLOCK command; the commands are edited in a menu form. The sequence of the commands is important; all of them are executed after all frame matchings.

DELETE Delete POINTS/LINES/FRAMES or clear all

Once this button is clicked, four more buttons show up for selection:

POINT allows deleting points
LINE allows deleting lines
FRAME allows deleting frames
CLEAR clears all points, lines and frames

When either POINT, LINE, or FRAME is selected, move the cursor inside the drawing window. Every click will delete the nearest item until nothing is available or the cursor is moved outside the drawing window.