DELAUNDO INPUT CONTROL FILE A .ctr file specifies how DELAUNDO will treat the nodes read from a .pts file. It is not necessary to use a .ctr file, all input can also be entered at a prompt. However, as FroD is a rather fast grid generation method, playing around with parameters is recommended to get a feel on how FroD behaves. Using a .ctr file makes this very easy. DELAUNDO looks first for a file 'delaundo.ctr' in your local directory. Depending on the parameters set in that file, it will or will not prompt you for any other input. If such a file does not exist, you are prompted for a filename. If you enter at this prompt: - a '?', you will be prompted for all required parameters, e.g. input file name, output file name .... - the string 'ALLPAR' (in captials!), you will be prompted for all parameters that apply to your current selections. E.g. you will be not prompted for an aspect ratio if you don't want stretched grids. If you enter a non-applicable answer, e.g. an integer rather than character, the default value is taken, if applicable. - the string 'HELPME'(in captials!), you will enter the help menu with the different sub-options (as you apparently did). - the string 'XAMPLE'(in captials!), you will be able to run a few demos. - the string 'RELEAS' (you guessed it), you will obtain infor- mation pertaining to the current release, like the version number you're running or changes from the last version. - a filename, DELAUNDO will try to read this file to extract the necessary information. In a .ctr file, information is adressed by six-letter capitalized keywords. The option selected or the value given or whatever, follows the line after the keyword. The keywords and the options are: IGNORE The rest of this line will be ignored. A '%' will work in the same way. HELPME The help menu will be called up and allows you to choose one of the help pages. XAMPLE The example menu will be called up and allows you to choose one of the examples. RELEAS Information about the current release. VERBOS This sets the verbosity. 0 gives you no output at all, except for warnings and fatal error messages, 5 will give you all there is to say. Default value is 3 (I think). ALLPAR Set to 't' or 'y', you will be prompted for all parameters that apply to your current selections. E.g. you will be not prompted for an aspect ratio if you don't want stretched grids. If you enter a non-applicable answer, e.g. an integer rather than character, the default value is taken, if applicable. Default is 'n','f'. INFILE The file name of the .pts file with the nodes. The default is 'delaundo.pts'. INFORM The input file can be formatted 'y','t', or unformatted 'n', 'f'. Input file formats, .pts, are explained in a separate help page. The default is 't'. NODEUS Set to 't' or 'y', this will make DELAUNDO use a given set of internal nodes. Note that only either of NODEUS or NODECO may be specified due to coding constraints. Default is 'f','n' NODECO Set to 't' or 'y', this will make DELAUNDO construct a set of internal nodes with the FroD method. Default is 't','y'. ANTICO Set to 't' or 'y', this will make DELAUNDO use the "anti-con- nectivity-information" specified in the .pts file. Default is 'f','n'. ALLDIS Set to 't' or 'y', this will make DELAUNDO remove all edges in the background grid that connect between non-consecutive boundary nodes, even if they reside on the same boundary seg- ment. Use it with discretion as this might lead to many many extra nodes needed for the disconnection of close surfaces. SPCRAT This floating point value specifies the ratio between the spacing gradients at the points of highest and lowest spacing Values higher than one will cause DELAUNDO to interpolate with a power law to extend the regions of fine spacing further into the domain. Default is 1. QTOLER This floating point value specifies the minimum fraction of the the maximum sidelength that the smaller sides must have in order to make the triangle acceptable. Default value is .65 DTOLER This floating point value specifies the fraction of the background mesh size that is being used as a minimum distance between nodes. Default value is .65 BTOLER This floating point value specifies the minimum fraction of the background mesh size that is being used as a minimum distance between nodes in the background grid. Default value is 2. STRETC Set to 't' or 'y', this will make DELAUNDO construct a layer of wedge type stretched triangles in form of rectangular boxes around frontal surfaces. Default is 'f','n'. DELTAS This floating point value specifies the thickness of the stretched layer in the scale of the other points. IF STRETC is specified as 't' or 'y', this parameter is required. MAXASP This floating point value specifies the maximum aspect ratio in the stretched layer. IF STRETC is specified as 't' or 'y', this parameter is required. ASKROW Set to 't' or 'y', this will make DELAUNDO prompt the user for more rows to be constructed, once the current counts have been exceeded. Otherwise the process will output the grid at the current stage. Default is 'f','n'. MVISRO This integer value specifies how many stretched, viscous rows are to be built. If ASKROW is set to 't' or 'y', the user will be prompted for more rows. (Limiting the number of rows is to be considered a debugging tool.) Default is 30000. ISMOOT This integer value specifies how many stretched rows of cells will be opened for isotropic retriangulation once the stretched process has terminated. 0 does not allow any retri- angulation, 1 allows retriangulation of the outermost cells, 2 allows retriangulation of the neighbors of the outermost cells as well. (Note that whenever stretched layers from different geometry segments impinge on each other, the "sew- up" becomes more gentle with ISMOOT:2). Default is 2. MISORO This integer value specifies how many isotropic rows are to be built. If ASKROW is set to 't' or 'y', the user will be prompted for more rows. (Limiting the number of rows is to be considered a debugging tool.) Default is 30000. FLATSW Set to 't' or 'y', this will make DELAUNDO swap diagonals in the final mesh in order to minimize the maximum angles. (Note that although the implementation is rather efficient to prevent any N**2 worst case, it is supposed to be used only to correct cases where the stretched process has stopped before reaching isotropy and the isotropic process created flat cells.) Default is 'f','n'. ANGMAX This floating point value specifies the maximum tolerable cell angle before FLATSW kicks in. (Note that this doesn't guarantee that all angles are below that value. A diagonal switch is not carried out if the maximum angle in the quadrilateral were to increase.) Default is 120. MCYCSW This integer value specifies how many swapping cycles are to be executed. Default is 10. LAPLAC If set to 't' or 'y', a Laplacian filter is applied to smoothen the mesh. Default is 'f'. Note that the applying the Laplacian to a stretched mesh will most likely fail due to mesh overlap. The ensuing process back toward Delaunay will not be able to recover. RSWEEP This integer value specifies the number of relaxation sweeps for the Laplacian. Default is 10. LPBETA This floating point value specifies how much the weight of the points increases with increasing vertex degree. 0. means fixed weights, 1. is maximum variance. Default is .5. RELFAC This floating point value specifies the relaxation factor for the Laplacian. The stability limits are [0.,1.], default is .75 MLEVEL This integer value specifies the number of multigrid levels that are to be produced. The maximum permissible depth is 10, default is 1. OUTFIL This string is the output file name. The default is 'delaundo.dpl'. OUTTYP This character determines the output type. Possible types are: t: the triangulation with the cells outside the domain removed. q: the triangulation of t, but with 6 nodes per triangle for quadratic elements. h: the convex hull with all the triangles. This is useful for creating a grid of scattered nodes for interpolation purposes or for debugging in case a boundary enforcement check fails. b: the background grid with the automatically added background nodes. Nodal values given are the node spacing as rho (1. state quantity) and the stretching magnitude multiplied by the spacing as rho*u (2. state quantity). i: the initial triangulation of the set of given nodes for debugging purposes. The default is 't'. OUTFOR This character determines the output format. Possible formats are: g: a VKB .gri file with grid. Only for t,q,h types. o: a VKB .out file with grid and solution. Only for t,q,h types. d: a dplot file. All types. USE THIS ONE! This fileformat is explained in a separate help page. u: a AvS ucd file. NOT really supported, so don't use it. Only t,b,h types. The default is 'd'. TITLE1,...,TITLE4 Titles for the g and o output formats. Titles 2-4 apply only to o. Defaults are ' '. DOLOGF Set to 't' or 'y', this will make DELAUNDO to write a logfile. Default is 'f','n'. LOGFIL This string is the name of the logfile. Default is 'delaundo.log'. ENDDAT Any information after this keyword will be ignored.