SiteMap Page 178


Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 Next

KNOWN ISSUE: Mass transfer rates may be incorrect for evaporating wall particles (Class 3 Error)


SYMPTOM:<br>The mass transfer rate of evaporating wall particles is computed using an incorrect transfer coefficient.<br><br>PROBLEM:<br>The mass transfer coefficient has...

KNOWN ISSUE: Using the Algebraic Slip Model with heat transfer may give incorrect results (Class 3 Error)


SYMPTOM:<br>Cases using the Algebraic Slip Model with heat transfer may give incorrect results.<br><br>PROBLEM:<br>Some inconsistencies in the implementation of the mass...

How to define a plane with specified dimensions in CFD-Post or CFX-Post? Can this plane be used to plot contours or as the source for streamlines?


Yes, this is possible. The attached document describes the process step by step.

SYMPTOM:
The CFX Solver fails at the start of the run with an error similar to:
/ansys/v110/CFX/bin/linux-amd64/solver-hpmpi.exe was interrupted by signal SEGV (11)
when a high-speed interconnect (such as Infiniband or Myrinet) is used for a parallel run.

(Note: HPMPI has been renamed Platform MPI starting at ANSYS R14.0)

PROBLEM:
CFX Release 11.0 includes HP MPI 2.2.5 for the use of parallel jobs using the HP MPI start methods. However, this version of HP MPI does not support some of the newer hardware/firmware that is now available for high-speed interconnects. In particular:
- HP-MPI 2.2.5 works with OFED 1.0 and 1.1, but not newer versions of OFED.
- HP-MPI 2.2.5.1 is the first release which supports ConnectX.


WORKAROUND:<br>If the latest version of HP MPI (currently 2.3) is downloaded from the HP website and installed, then CFX Release 11.0 can pick this up and use it instead of HP 2.2.5. The...

**** Entered By: jjdoyle @ 05/18/2009 15:31 ****

Q. The Workbench Simulation documentation includes the comment: "If your CAD system split the cylinder into two or more faces, select all of the faces when defining the bearing load." This apparently will not work. Only one face is used. What does a reasonable man have to do to get this to work?

A. This will only work provided the cylinder faces belong to the same part. Go back to DM and form a new multi-body part from the split cylinders.


**** Entered By: jjdoyle @ 05/18/2009 15:31 ****<br><br>Q. The Workbench Simulation documentation includes the comment: "If your CAD system split the cylinder into two or more...

Why does every "CAD Integration*intel" directory have a copy of ComponentSystem.dll? These DLLs all appear to be identical, and consume more disk space than is necessary. One would think that one copy of this file, in a known location, would be sufficient.


ANSYS 12.0 no longer uses the Windows registry. This is being done at the request of major customers who do not want to have any registry settings or software installed on a local Windows registry...

KNOWN ISSUE: Pitch angle calculation incorrect when initial mesh spans the theta = pi plane (Class 3 Error)


<br>SYMPTOM:<br>The CFX-Solver may calculate the pitch angle incorrectly when the initial mesh spans the plane where the theta coordinate is equal to pi (or...

KNOWN ISSUE: The Optimized R. C. B. partition type can give incorrect or non-optimal results, or lead to a crash (Class 3 Error)


SYMPTOM:<br>If the CFX-Partitioner is set to use the Optimized Recursive Coordinate Bisection partition type, then the partitioner may fail with a segmentation violation, it may produce...

KNOWN ISSUE: Callbacks on fluid/solid interfaces (Class 3 Error)


SYMPTOM:<br>The documentation indicates that conservative values of temperature are used in callbacks on fluid-solid interfaces. However, whereas areaAve(T) does use the conservative value,...

KNOWN ISSUE: High Speed Wall Functions produce poor results for Low Speed flow (Class 3 Error)


SYMPTOM:<br>The CFX-Solver may experience robustness problems, and produce overshoots and undershoots in the temperature solution at walls, when the viscous work term is enabled for low...

KNOWN ISSUE: Diffusion discretization at non-overlap GGI boundaries may use volume fraction instead of contact area fraction (Class 3 Error)


SYMPTOM:<br>The diffusion term discretization at non-overlap GGI boundary conditions may use volume fraction where it should use contact area fraction. This will not normally lead to a large...

SYMPTOM:
A CHT case that includes 1:1 internal solid-solid domain interfaces fails during the first timestep with the following error:

+--------------------------------------------------------------------+
| Writing crash recovery file |
+--------------------------------------------------------------------+

+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction. |
| Message: |
| Stopped in routine ASS_GLOB_ZIFVX |
| |
| |
| |
| |
| |
+--------------------------------------------------------------------+

PROBLEM:
The problem is caused by a limitation in the solver algorithms. These do not account for 1:1 interfaces for internal solid-solid interfaces.


WORKAROUND:<br>Change the interface type to GGI, or, create separate solid domains.<br><br>FIXED IN:<br>ANSYS CFX Release 12.0.

KNOWN ISSUE: Static Entropy incorrect for Flamelet/BVM/ECFM combustion model (Class 3 Error)


SYMPTOM:<br>Static Entropy is calculated incorrectly by the CFX-Solver when using the Flamelet, Burning Velocity (BVM) or Extended Coherent Flamelet (ECFM) combustion...

KNOWN ISSUE: Wrong Wall Heat Flux for moving walls when using Total Energy model (Class 3 Error)


SYMPTOM:<br>In cases where moving walls (mesh motion) are used in conjunction with the Total Energy model, the heat flux at any non-adiabatic moving wall is...


How is it possible to detect interfaces automatically that are not 1:1?


<br>In order to detect interfaces automatically, follow these steps:<br>¿ Generate your mesh within one meshing instance of ANSYS Meshing to obtain a single .cmdb...

KNOWN ISSUE: The CFX-Solver fails to write a results file before exiting, after losing contact with the license server


SYMPTOM:<br>The CFX-Solver may exit unexpectedly with messages like:<br><br>+--------------------------------------------------------------------+<br>| An error has...

KNOWN ISSUE: CFX-Mesh surface mesh is coarser than settings in the Default Face Spacing


SYMPTOM:<br>In some circumstances the surface mesh created in CFX-Mesh may be significantly coarser than the constant spacing specified in the Default Face...

KNOWN ISSUE: Use of hybrid variables in custom wall functions (Class 3 Error)


SYMPTOM:<br>If a custom wall function is created using an expression that includes variable values, then the conservative value of those variables are used. If the user tries to use the...

KNOWN ISSUE: Crash restarting transient particle case with solid region


SYMPTOM:<br>If a restart is carried out for a transient simulation using both the particle transport model and a solid domain, then the CFX-Solver will stop before calculating anything with...

KNOWN ISSUE: Problems with thermodynamic properties for real gas combustion materials (Class 3 Error)


SYMPTOM:<br>For the materials with the Material Group set to 'Real Gas Combustion', the specific heat has a discontinuity when plotted against temperature, leading to errors in...

KNOWN ISSUE: The ATM method may not be applied if beta features are not enabled when Turbogrid starts up


SYMPTOM:<br>If Turbogrid is started with beta features not active, then the Automated Topology Meshing (ATM Optimized) method is not applied, even if beta feature are subsequently enabled...

Class 3 Error

SYMPTOM:
For Oxygen real gas materials in MATERIALS-redkw.ccl, MATERIALS-pengob.ccl, MATERIALS-rgcomb-redkw.ccl and MATERIALS-rgcomb-pengrob.ccl, the density, specific heat, enthalpy, entropy and vapour pressure etc will be in error.

PROBLEM:
This is due to a bug in data used by the CFX Solver for the acce


WORKAROUND:<br>Edit the relevant materials files or the definition file. The correct value for Accentric Factor for Oxygen (O2, O2l, O2v, O2RK, O2RKl, O2RKv) is...

KNOWN ISSUE: Incorrect accentric factor for oxygen (Class 3 Error)


SYMPTOM:<br>For Oxygen real gas materials in MATERIALS-redkw.ccl, MATERIALS-pengob.ccl, MATERIALS-rgcomb-redkw.ccl and MATERIALS-rgcomb-pengrob.ccl, the density, specific heat, enthalpy,...

Can I orient a local coordinate system with geometry in Workbench Simulation/Mechanical?


In the details section of the local coordinate system (CS), you may orient up to two axes with respect to geometry (face, edge, or vertices). In the attached example, one CS was oriented using...

Will all the ETABLE items be available through the new spreadsheet (user-defined results) in Workbench Mechanical?


They may not show in the spreadsheet, but you can still use the user-defined results to get the SMISC and NMISC items from known elements that exist in our mesh (solids, shells, and beams, but not...