03/10/23 RELEASE VERSION 9.34.2

Bugs Fixed:

• Corrected a fatal error when tracking boundary-edges on adjacent BL intersecting surfaces for use with AFLR4.

11/20/22 RELEASE VERSION 9.33.20

Enhancements/Additons:

• Changed all sprintf calls to snprintf.

11/10/22 RELEASE VERSION 9.33.19

Enhancements/Additons:

• Add changes for compatibility with revised AFLR4.

Bugs Fixed:

• Correct boundary-edge memory allocation with internal boundary-edges on re-generated BL intersecting surfaces.

08/29/22 RELEASE VERSION 9.33.16

Enhancements/Additons:

• Add changes for compatibility with AFLR4.

05/23/22 RELEASE VERSION 9.33.15

Enhancements/Additons:

• Add capability to preserve boundary-edges on individual surfaces for use with AFLR4.

10/01/21 RELEASE VERSION 9.32.2

Enhancements/Additons:

• Changes for compatibility with DGEOM.

08/30/21 RELEASE VERSION 9.32.14

Enhancements/Additons:

• Changes for compatibility with UG3 library BC setting routine ug3_set_ibcibf.
• Changes for compatibility with UG library routines and parameter initialization.
• Changes for compatibility with DGEOM and AFLR4.

03/17/20 RELEASE VERSION 9.31.3

Bugs Fixed:

• Modify secondary check counter used for BL candidate node checking so that it works as intended.
• Corrected an issue that resulted in incorrect termination of BL advancement. The issue only occurred if the BL generating surface was nearby a surface that intersects the BL region. In those cases proposed BL nodes could be rejected even though they were not visible to the surface that intersects the BL region.

07/03/19 RELEASE VERSION 9.30.2

Enhancements/Additons:

• Added capability to time CPU usage of various routines.

06/24/19 RELEASE VERSION 9.29.12

Enhancements/Additons:

• Changes for compatibility with DGEOM LIB changes.

05/03/19 RELEASE VERSION 9.29.10

Enhancements/Additons:

• Changes for compatibility with AFLR4 LIB changes.

02/16/19 RELEASE VERSION 9.29.9

Enhancements/Additons:

• Modified Message_Flag (mmsg) usage for values of 0 (no output) and -1 (minimal output).

11/20/18 RELEASE VERSION 9.29.5

Enhancements/Additons:

• Changes for compatibility with AFLR4 revisions.
• Changes for compatibility with AFLR4 geometry setup API.

08/17/18 RELEASE VERSION 9.29.2

Enhancements/Additons:

• Added an option for checking the volume of all 12 possible tetrahedral BL elements that could be created for each BL face. This also insures full pyramid validity. This option is turned on,off with the input parameter mblchkv=1,0 and is on by default.
• Added normal distance checking between BL points and surfaces that intersect the BL region (symmetry plane).
• Changes for compatibility with AFLR4 discrete geometry API.

Bugs Fixed:

• Corrected an error in checking points on surfaces that intersect the BL region (symmetry plane) that could lead to early termination of BL advancement on those surfaces.

02/23/18 RELEASE VERSION 9.28.1

Enhancements/Additons:

• Modified boundary surface node checking to better treat nodes on boundary surfaces that intersect the BL region differently from those on regular surfaces.
• Added re-ordering of boundary edge nodes on periodic surface pairs. This only impacts cases with periodic boundary surfaces that intersect the BL region and that do not use BL region element combination for (prisms, pyramids and/or hexs) and only have BL region tet-elements.
• Modified check of large included angles (angblisimx) between BL surface faces and those of rebuild surfaces that intersect the BL region. Previous versions simply stopped if this was found. The current version stops BL generation at those intersection nodes and continues on with all other operations.

12/05/17 RELEASE VERSION 9.27.0

Enhancements/Additons:

• Modified algorithm for classifying discontinuous surface nodes on BL generating surfacesCorrect an error in BL normal vector smoothing.

Bugs Fixed:

• Correct an error in BL normal vector smoothing.

08/03/17 RELEASE VERSION 9.26.78

Enhancements/Additons:

• Added number of BL layers to standard output.

Bugs Fixed:

• Reduced geometry tolerance used for locating points on edges and in faces of surfaces that intersect the BL region. This eliminates erroneous projections with small BL normal spacing along edges very close to the wall.

02/23/17 RELEASE VERSION 9.25.75

Enhancements/Additons:

• Moved ice3_split_data routines to UG3 library (removes ANBL3 dependency on ICE3 library).
• Changes for compatibility with 64-bit integers.
• Modified included angle check for surfaces that intersect the BL region to include transparent BL generating surfaces as possible neighbors.
• Added a check that prevents BL nodes from being rejected when they are advancing away from another potentially interfering boundary. Previously this check could made it appear that the normal distance to the potentially interfering boundary was very small.
• Modified the default value for the number of layers to smooth BL normal spacing (and thickness) over from 5 layers to 20 layers. This prevents element quality degradation when the difference in spacing between adjacent BL generating surfaces is up to an order of magnitude.
• Modified open method. With the new method the option flags have changed. The new -open2 option is nearly the same as the previous -open option. -open (or mopen=1) : Generate an open BL region grid for a closed domain. With an open BL region the BL grid is generated and the domain is only the generated BL region. No isotropic region elements are generated. With a closed domain all of the input surfaces are retained and standard boundary surface face reorientation is done as needed (same as default). -open2 (or mopen=2) : Generate an open BL region grid for an open domain. With an open BL region the BL grid is generated and the domain is only the generated BL region. No isotropic region elements are generated. With an open domain only the input surfaces that are used for BL generation are retained and no individual boundary surface face reorientation is done. All of the boundary surface faces are assumed to be properly orientated such that RH rule ordering points in the direction of BL generation. The only possible face reordering is a global reordering using the -revbl (mrevbl=1) option. If the input surface grid is a non-closed surface then the BL region will be aligned normal to the surface edges. The output grid includes a new boundary surface for the exposed surface of the BL region with a boundary surface face ID equal to the maximum ID plus 1.
• Reinstated setting of number of BL tet-elements.

11/28/16 RELEASE VERSION 9.21.68

Enhancements/Additons:

• Changes for compatibility with ICE capability for grids with hex-elements that have 2:1 split faces.
• Revised BL element quality checks to omit face angle checks if the starting boundary surface mesh is of low quality (or was generated with an anisotropic metric adaptation method).
• Revised BL element quality checks to omit element dihedral element checks that are dependent upon the initial face angles if the starting boundary surface mesh is of low quality (or was generated with an anisotropic metric adaptation method).
• Changes for compatibility with revised BL normal vector methodology.
• Added most visible normal vector method to normal vector routines. The parameter mbv_mode now controls the method for normal vector determination. If mbv_mode = 1 then use LS method to determine the node normal vector that has the minimum deviation with respect to the surrounding face normal vectors. This is the default. If mbv_mode = 2 then use a most-visible method to determine the node normal vector that maximizes the minimum tetrahedral volume for the surrounding faces. If mbv_mode = 3 then use a simple averaging method to determine the node normal vector.
• Added determinant tolerance to least-squares normal vector algorithm.

08/19/16 RELEASE VERSION 9.19.58

Enhancements/Additons:

• Added capability for transparent/embedded surfaces that intersect the BL region to have free edges that also intersect the BL region.
• Added more accurate determination of node locations along edges that intersect the BL region (both between surfaces and free).

08/10/16 RELEASE VERSION 9.18.57

Enhancements/Additons:

• Changes for compatibility with revised libraries.

07/28/16 RELEASE VERSION 9.18.56

Enhancements/Additons:

• Changes for compatibility with new method for least-squares optimized BL normal vectors.

Bugs Fixed:

• Corrected an error with reading a TMP file that only could happen when using mpfrmt=0 to return the full volume mesh rather than the low memory file writer within BL mesh generation.
• Corrected an error with MESH file type when used for internal file writer.
• Corrected an error computing the distance between BL nodes and surfaces that intersect the BL region. This error could cause boundary recovery to fail due to advancement of the BL outside the domain and causing intersection of the BL region with a surface that intersects the BL in a region where there should be no intersection.

04/07/16 RELEASE VERSION 9.15.48

Enhancements/Additons:

• Changes for compatibility with UG3 routine that writes a grid file.

03/19/16 RELEASE VERSION 9.15.47

Enhancements/Additons:

• Minor syntax change in if check.
• Updated internal reduced memory read/write API for the final volume grid.
• Combined ANBL3 Lib and ANBL3_API Lib. ANBL3_API Lib is no longer separate or used.

12/02/15 RELEASE VERSION 9.13.43

Enhancements/Additons:

• Added metric blending capability to surface grid regeneration for planar surfaces that intersect the BL region.

Bugs Fixed:

• Modified procedure to reset standard surfaces from standard to BL surfaces if they are adjacent to a BL generating surface. The original could set inappropriate surfaces to BL generating surfaces.

09/28/15 RELEASE VERSION 9.12.40

Enhancements/Additons:

• Added modifications as needed for new versions of AFLR4 and DGEOM.

Bugs Fixed:

• Modified code so that quad surface faces can exist on non-BL generating surfaces and BL generating ones with the -blc3 option (pyramid transition from quad faces). Previous versions would fail if quads existed on both.
• Corrected surface extraction issue with open option BL regions.

02/24/15 RELEASE VERSION 9.9.25

Enhancements/Additons:

• Added spline fit capability for curves on rebuild surfaces that intersect BL region.

12/23/14 RELEASE VERSION 9.9.21

Enhancements/Additons:

• Added capability for BL generating embedded/transparent surfaces that have non-manifold (multiple) connections between them and other embedded/transparent and/or solid surfaces.

08/14/14 RELEASE VERSION 9.7.19

Enhancements/Additons:

• Added capability to regenerate surface grids using the AFLR4 3D surface generator. This is used to rebuild surfaces that intersect BL regions. Previously a planar projection was used along with AFLR2 to generate projected 2D grids and re-project back to the true surface. That imposed restrictions on curvature for an individual surface. Those restrictions are no longer valid. Note that AFLR4 uses the input surface grid as a discrete definition of the geometry and resulting curvature is limited by the input resolution. Also, AFLR4 automatically checks for planar surfaces, such as symmetry planes, and uses 2D generation in those cases.
• Removed input parameter angqprojuv that was used to check if surface projection was valid. This check used for each surface that intersected the BL region and required regeneration. It is not applicable now that AFLR4 surface generation with mapping generation is used.
• Modified internal API for surface search (ug3_srchbf) to allow for a two-pass algorithm that uses a large tolerance on the second pass to find locations that are off the surface and near a surface node.

07/17/14 RELEASE VERSION 9.6.17

Enhancements/Additons:

• Revised BL normal smoothing at discontinuous locations on the intersection of surfaces that intersect the BL region.

06/21/14 RELEASE VERSION 9.5.17

Enhancements/Additons:

• Eliminate majority of output during surface regeneration for surfaces that intersect the BL region.
• Changed search flag for projecting BL normals on rebuild surfaces that intersect the BL region to prevent search failure on the first pass of BL grid generation.
• Revised discontinuity check for turning off least-squares BL normals so that is based on an edge discontinuity as defined by the discontinuity angle angbd.
• Modified home BL normals are determined on surfaces that intersect the BL region using an assumptions of symmetry.
• Revised nearest nearby node factor so that is based on the BL node related factor cdfnbl rather than the field related factor cdfn when checking how close a BL node can come to an edge on a surface that intersects the BL region.
• Corrected an issue during BL grid generation when fixed surfaces that intersect the BL region are used with hex elements and pyramid transition. Previously the last BL level on the fixed intersecting surface was terminated with that combination of options. They are now handled the same as with split face transition.
• Added removal of transparent surfaces that are set to generate an attached BL region if an open BL mesh is requested (-open or mopen=1).
• Added reset of BL thickness (deldef=0 or -bldel 0) to the option maximum BL thickness option -bldelmax.
• Modified BL global termination parameters. The BL global termination parameter mblend now can only be 0 or 1 (on or off). The old option for mblend=2 essentially behaved the same as mblend=1 except that it ignored the BL thickness (and that can be controlled using -bldel or deldef or -bldelmax. The maximum normal-direction-aspect-ratio parameter cblmnr now helps control global termination and functions in that regard the same as the termination maximum normal-direction-aspect-ratio parameter cblnrendmx, which is now deleted. Also, changed the name of the termination minimum normal-direction- aspect-ratio parameter cblnrendmn to cblmnrmin (and not often varied).

Bugs Fixed:

• Corrected an initialization error that could occur after BL grid generation with hex elements and pyramid transition along with constrained/fixed boundary surfaces.

05/13/14 RELEASE VERSION 9.2.9

Enhancements/Additons:

• Eliminate library dgeom output of error message when locating a point on a surface.

02/02/14 RELEASE VERSION 9.1.6

Enhancements/Additons:

• Convert to new ug parameter structure scheme and eliminate use of Error_Message.

10/30/13 RELEASE VERSION 8.49.57

Enhancements/Additons:

• Added capability for transparent surfaces with free edges that intersect the BL region.
• Modified quad pyramid transition capability so that all quad faces are retained if mquadp=2.
• Modified final layer termination to include points that are on fixed constraint surfaces that intersect the BL region. This preserves hex element generation if the BL generating surface contains quad faces.
• Added minimum length scale for checking intersections with non-BL generating surfaces too account for constraining surfaces with high-aspect ratio faces that are near the BL region.
• Added capability to generate BL nodes along curves on continuous surfaces that intersect the BL region. Previous versions would generate BL nodes along curves if the curve was also a geometric edge (discontinuous surfaces).

Bugs Fixed:

• Corrected a possible spacing error in re-generating edges of rebuild surfaces that intersect the BL region.
• Corrected a possible error with regenerating curves of periodic rebuild surfaces that intersect the BL region.

09/16/13 RELEASE VERSION 8.46.54

Enhancements/Additons:

• Added process to reconnect tria-faces derived from quad-faces on the surface at singular points (such as saddle points). This modifies the ordering for generating BL elements at such points and allows positive volume elements to be generated. The number of tria-faces that surround such singular points should be minimized. For example the corner of a box has three surfaces and three trias (one for each surface) are optimal.
• Added a check of quad face quality on the outer interface of BL regions when hex element combination is selected (mblelc=2). Hex element formation is turned off locally if a quad face is highly curved or of low quality. The curvature is checked to insure that if the outer quad face is represented by tria faces the dihedral angle between them doesn't represent a discontinuity as defined by angbd. Quality is checked by insuring that the corner angles of the outer quad don't exceed angqbfq (new parameter with a default of 160 deg). If hex element formation is locally turned off then prism elements are formed instead.

08/22/13 RELEASE VERSION 8.44.53

Enhancements/Additons:

• Modified quad face to pyramid transition process by turning off hex generation from quad faces that do not terminate with all face points on the same BL level.
• Modified the process that saves the last BL normal spacing values for use in BL blending by AFLR3.

Bugs Fixed:

• Corrected a potential indexing error in the process that saves the last BL normal spacing values.

03/16/13 RELEASE VERSION 8.42.51

Enhancements/Additons:

• Added modifications to allow for very long file names. Previous versions are limited to file path names with about 100 characters or less. The current version allows path names with about 1000 characters (500 on Windows) or less.

Known Issues:

• Anisotropic blending is BETA mode at best.
• With hex elements the top face can be inverted at one node (corner angle > 180). A check will be added in the future.
• With hex elements the mquadp=1 (isotropic) or 2 (BL cases) option to use quad face to pyramid element transitions in isotropic regions or for transition from hex to pyramid elements does not work if their are quads on an embedded surface (that is not a source surface). For example a wake sheet with attached BL region.

02/15/13 RELEASE VERSION 8.40.50

Enhancements/Additons:

• Modified limitation on the number of BL layers that will be generated for a given boundary surface patch (of the same ID). This process prevents regions with coarse BL normal resolution from engulfing regions with fine resolution (see Release Notes comments for 8.33.40). It will not impact cases with constant or similar initial BL normal spacing. A new input parameter mnbllim can be used to turn this process on. It is on if mnbllim=1 and off if mnbllim=0. By default it is off. For cases with large variations in initial normal spacing it probably should be turned on. If the number of BL layers has been set on individual surface patches then this process will not override those selections.
• Added additional control for limiting the difference in number of BL layers between adjacent nodes to one (nbldiff=1), if specified, and if the number of BL layers for each surface ID patch is specified. If the number of layers is specified for one or more surface ID patches and if nbldiff=1 then the number of layers generated in a given BL grid generation step will automatically be reduced to one actual BL layer per step. This allows the normal limiting of BL layers between adjacent nodes to work at the junction between surface patches if they each have a different number of BL layers specified. Note that even with this change the number of BL layers difference between adjacent nodes can still exceed the limit set by nbldiff. This is possible only if multiple layers are being generated on each step (typically very close to the surface) and there is local termination of the BL generation. If cbldsm is reduced from the default of 0.5 then the region where multiple layers are generated is reduced. If cbldsm=0 then only one actual BL layer will be generated at a time and the limit set by nbldiff will always be fully met. The CPU time penalty with cbldsm=0 can be a factor of two or more. However, this increase is only for the BL generation phase and all other aspects are the same. So the overall impact is highly case dependent.
• Added angle quality check to uv projected surface used for regenerating rebuild surfaces that intersect the BL region. The maximum angle allowed on the projected surface is angqprojuv with a default value of 175 degrees. If the initial surface has a triangular face with a corner angle above that then an error will be generated. Increasing the maximum angle allowed, angqprojuv, may produce a valid mesh. However, it may not be usable and may also produce an error in the process that regenerates the surface. Any error in edge grid generation or in AFLR2 is the result of a problem with the rebuild surface.
• Modified search tolerance used in regenerating rebuild surfaces that intersect the BL region. With previous versions fatal errors in edge grid generation could be encountered due to points being outside the boundary edges for a particular surface by relatively small distance.

Bugs Fixed:

• Corrected an issue with topology of rebuild surfaces that intersect the BL region that could occur if some (not all) of the rebuild surfaces are periodic. The topology error typically resulted in fatal errors in boundary edge grid generation.

Known Issues:

• Anisotropic blending is BETA mode at best.
• With hex elements the top face can be inverted at one node (corner angle > 180). A check will be added in the future.
• With hex elements the mquadp=1 (isotropic) or 2 (BL cases) option to use quad face to pyramid element transitions in isotropic regions or for transition from hex to pyramid elements does not work if their are quads on an embedded surface (that is not a source surface). For example a wake sheet with attached BL region.