Simcenter STAR-CCM+ 如何避免Adjoint cost function not supported on derived parts错误

2023-01-18T12:52:36.000-0500
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摘要

在进行adjoint分析的时候,如果adjoint cost function是建立在derived parts上,在运行计算的时候会出现“Adjoint cost function not supported on derived parts”错误。 本文介绍一种work around,来避免这样的错误的发生。


详细信息

问题描述:
(1)在Adoint计算中,有时候希望将基于derived part的Report作为Adjoint Cost Function
(2)但是这样的Adjoint Cost Function是不可微分的,因此在执行 Adjoint计算时候会报错:Adjoint cost function not supported on derived parts
(3)本文旨在探讨如何避开使用derived part,又不引入额外的interface (引入额外的interface可能会使网格质量变差,从而影响收敛性),而使Adjoint正常工作

示例-问题定义
(1)在发动机计算中,我们希望将Z=-0.45m处的swirl作为adjoint cost function
image.png
示例-Swirl定义
(1)其中Swirl的定义如下:
image.png
示例-定义Flag函数
(1)定义一个Flag函数,将想要的区域选出来,例如目标是Z=-0.45m的
         截面,可以在Flag函数中定义一个【-0.46,-0.44】的范围出来,来
         代表Z=-0.45m这个截面

image.png
示例-定义Field Function
(1)定义出需要的函数,注意${Flag}函数出现的位置
image.png
示例-定义Report
(1)定义出需要的Report,此时report的输入Part选择计算域Region
image.png
总结
(1)此时可以从创建的expression report SwirlRatio_k,去创建Adjoint  
         Cost Function
(2)需要注意的是,目前在Adjoint Framework下,只支持全局坐标系,
         因此若在Field Function中引入局部坐标系下的变量,会出现以下错 
         误:
Warning: Differentiation of "CellAngularMomentum_Laboratory.Cartesian 1" is not supported
Warning: Differentiation of "CellMassMomentOfInertia_Laboratory.Cartesian 1" is not supported
Warning: Differentiation of "CellAngularMomentum_Laboratory.Cartesian 1" is not supported
Warning: Differentiation of "CellMassMomentOfInertia_Laboratory.Cartesian 1" is not supported
Warning: Differentiation of "CellMassMomentOfInertia_Laboratory.Cartesian 1" is not supported
Warning: Differentiation of "CellMassMomentOfInertia_Laboratory.Cartesian 1" is not supported
Warning: Differentiation of "CellAngularMomentum_Laboratory.Cartesian 1" is not supported
Warning: Differentiation of "CellAngularMomentum_Laboratory.Cartesian 1" is not supported
A floating point error has occurred. The following error has been logged:
  floating point exception [invalid operation], the specific cause cannot be identified
Please refer to the troubleshooting section of the User's Guide.
Command: RunAdjoint
   error: Server Error



 

知识库文章 ID# KB000047120_ZH_CN

内容

摘要详细信息

关联组件

Design Manager Electronics Cooling In-Cylinder (STAR-ICE) Job Manager Simcenter STAR-CCM+