Procast充型无法完成的原因及解决方法

1、Procast充型无法完成的原因及解决方法充型无法完成的原因及解决方法？无法充满的原因：检查PREFIXp.ou戊件。1、 Solution is not converging （计算程序跳出）原因：边界条件、材料参数、网格等可能有问题，导致计算不收敛。解决方法：检查precast中的边界条件，初始条件等；修改CGSQ参数，采用不用的求解模型；增大收敛公差 CONVV （最大0.5）;重新划网格。2、 A cold shut switch off has been initiated at （流场计算停止，温度场计算继续，但出现异常。 Thermal Only Model ）原因：冷隔算法默认

2、为启动状态，如铸件温度降低太多，则停止充型计算。如果实际上并无冷隔产生，则需调整参数重新计算。解决方法：调整界面换热系数，降低冷却速度。在PREFIXp.dat中添加参数：COLDSHUT 0,关闭冷隔算法。裹气的判断对于裹气缺陷的判断，采用v。1 d s选项，观察充型过程中的气体分布，同时考虑周 围的排气情况，及金属液温度。主要的参数设置RPProCAST provides the access to many Run parameters, in order to allow the treatment of all kind of situations. However, for an

3、everyday use, only a few Run parameters have to be set or modified. This section is presenting the most "popular" Run Parameters that should be set, with proposed values, for each main family of processes. These parameters recommendations may be slightly different from previous ver

4、sions, as the solver algorithms have been modified. These recommended Run parameters correspond to the one which are pre-defined in the "Pre-defined Run Parameters" window. It is thus advised to activate the "pre-defined" set corresponding to the process and then

5、to set the appropriate stopping criteria.For all processesStopping criteria(it is advisable to set a stopping criterion in order to limit the CPU time and avoid unnecessary storage of results)TFINALTSTOPPorosityPOROS = 1 (this model is now recommended for all processes)MACROFS = 0.7FEEDLEN = X (The

6、value FEEDLEN depends upon the size of the mushy zone and thus, the size of the casting. A value ranging from a few millimeters to a few centimeters is recommended. This should be calibrated with experiments. A value of 0 is not advised as this will produce a uniform microporosity throughout the par

7、t, beside the macroshrinkage)Gravity castingTimestep handlingDT = 1e-3 DTMAXFILL = 1e-1DTMAX = 0.5 - 5 (depending upon the size of the model and thus the solidification time)PorosityPIPEFS = 0.3GATEFEED = 0FillingWSHEAR = 2FREESFOPT = 1WALLF = 0.8LVSURF = 0.98High pressure die casting (HPDC)Timestep

8、 handlingDT = 1e-6 to 1e-4 (it depends upon the initial velocity of the first stage)DTMAXFILL = 1e-2DTMAX = 0.2 - 1 (depending upon the size of the model and thus the solidification time)PorosityPIPEFS = 0.0GATEFEED = 1FillingWSHEAR = 2FREESFOPT = 1WALLF = 0.99LVSURF = 1.0PINLET = 1 for a pressure f

9、illing or PINLET = 0 for a velocity/inlet fillingLow pressure die casting (LPDC)Timestep handlingDT = 1e-3DTMAXFILL = 1e-2 (it is important to limit the timestep during the filling of an LPDC part. A value of 1e-2 is recommended for filling time of about 5-20 s.).DTMAX = 0.2 - 1 (depending upon the

10、size of the model and thus the solidification time)PorosityPIPEFS = 0.0GATEFEED = 1FillingWSHEAR = 0 (never use WSHEAR = 2 for LPDC)FREESFOPT = 1WALLF = 0.8LVSURF = 1.0PINLET = 1 for a pressure filling or PINLET = 0 for a velocity/inlet fillingTilt castingTimestep handlingDT = 1e-3DTMAXFILL = 1e-1DT

11、MAX = 0.5 - 5 (depending upon the size of the model and thus the solidification time)PorosityPIPEFS = 0.3GATEFEED = 0FillingWSHEAR = 2FREESFOPT = 1WALLF = 0.8TILT = 1DETACHTOP = 1Centrifugal castingTimestep handlingDT = 1e-3DTMAXFILL = 1e-1DTMAX = 0.5 - 5 (depending upon the size of the model and th

12、us the solidification time)PorosityPIPEFS = 0.3GATEFEED = 0FillingWSHEAR = 2FREESFOPT = 1WALLF = 0.8RELVEL = 1由于材料名称造成的计算出错在材料数据库中添加材料时，其名称中不能包含特殊字符。在运行 datacast 中，可能会出错，其出错信息如下：An enthalpy function is referenced in 5 0 data set 2 which has not been given.分析可能原因：该字符与计算中的某些关键字冲突。多次浇注模拟分期浇注，与补浇工艺略有不同，

13、也可以说补浇是一种特殊的分期浇注，完全充满然后收缩一定量后再次浇注。1、网格不宜太大，浇注系统厚度方向也要保证3 层网格以上， （要想得到更好的充型结果，对于其他模拟同样适用。 ）2、直浇道和铸件分开建模，铸件按正常情况设置热交换系数，直浇道适当保温（设置较小的热交换系数） ，防止金属凝固。3、设置正常的边界条件，定义时间变化曲线。4、运行参数，改LVSURF为一个大于1的值，防止提前终止流场计算。5、在P.dat 中手动添加参数： DETACHTOP1 （更好的控制金属液与铸型顶部的分离）COLDSHUT （关闭冷隔计算）0如何使用 niyama 准则 niyama 准则依赖于温度梯度，网格

14、变化会影响结果，目前看来并不是非常准确。当采用默认单位时： cm C色标设置一般为：0-3045使用切面分析内部的危险点（ spot ）选择适当的值，设置Cutoff 来显示分布情况一般来说 procast 自带的 shrinkage porosity 更准确， 但通过 niyama 准则可以更好的分析 早期凝固区域中未形成孤立液相区的缺陷。重力铸造-参数设置FREESFBAL = 2 (to be added manually in the p.dat file)This can be used in Gravity casting (and only in Gravity casting)

15、 when you have an important horizontal free surface. Sometimes, the free surface is getting quite agitated. FREESFBAL = 2 is calming down this free surface which corresponds much more to the reality. In the code, it correspond to a more accurate treatment of the mass balance at the free surface, whi

16、ch removes the kind of instability that we observed in large horizontal free surfaces.重力铸造-浇注速度设置本帖最后由 奔跑 于 2009-6-1 20:58 编辑实际浇注时，浇包距离浇口一般约 1020cm ，这时金属液到达浇口的速度约为1m/s2m/2 ，所以在设置速度边界条件时，要注意控制入流面积来保证速度，否则充型 结果会产生较大偏差。In usual casting conditions,the ladle(or crucible) is very often at a minium of 10 o

17、r 20 cm above the top of the pouring cup. Thus,physically,it is advised to set an inlet velocity(at the limit of the model) between 1 and 2 m/s and not smaller. As a consequence, the inlet diameter should be set accordingly in order to have the right inflow of metal. If a too small inlet velocity is

18、 defined (e.g.10cm/s), the inlet diameter should be too large and due to the strong acceleration on the first centimers, the diameter of the accelerating liquid jet will decrease very much. This situation is quite difficult to be modeled and shoule be avoided.Finally, one should always be careful that the mesh size bel