速度残差

hongjiewang

smoothSolver:  Solving for Ux, Initial residual = 1, Final residual = 1.00985e-16, No Iterations 15
smoothSolver:  Solving for Uy, Initial residual = 1, Final residual = 1.07542e-16, No Iterations 15

请问我求解算例的时候，发现速度的第一次迭代残差都是1。
我用相同的求解器跑了其他的算例，速度的第一次残差也是0.1的量级。
请问如何优化这种问题~

李东岳

第一次是1没问题。0.1也没问题。这非常正常。不需要优化。

hongjiewang

@李东岳谢谢老师回复~
老师可以帮我看一下这个错误怎么修改吗，按照您之前的一个帖子，定义了一个随时间变化的热流边界~

    HEATED
    {
        type       externalWallHeatFluxTemperature;
        mode     flux;
        q            coded;       // Heat flux
        code
        #{
             scalar q=*this;
             scalar t = this->db().time().value();       
             if(t >= 0 && t<=1.5)
             {
                  q = 180000;
             }             
             else if(t<=3)
	     {
	          q = 200000;
	     }	     
	     else if(t<=4.5)
	     {
	          q = 250000;
	     }	     
	     else if(t<=6)
	     {
	          q = 300000;
	     }	     
	     else
	     {
	          q = 0;
	     }
	     q.writeEntry("", os);	     
        #}; 
        value           uniform 300;
        kappaMethod     lookup;
        kappa           "K";
    }

/home/dyfluid/OpenFOAM/dyfluid-v2006/run/bianhuaQ/0/SOLID/T.boundaryField.HEATED:32:23: error: cannot convert ‘const Foam::PatchFunction1Types::qPatchFunction1ScalarField’ to ‘Foam::scalar’ {aka ‘double’} in initialization
/home/dyfluid/OpenFOAM/dyfluid-v2006/run/bianhuaQ/0/SOLID/T.boundaryField.HEATED:33:31: error: ‘const class Foam::PatchFunction1Types::qPatchFunction1ScalarField’ has no member named ‘db’
/home/dyfluid/OpenFOAM/dyfluid-v2006/run/bianhuaQ/0/SOLID/T.boundaryField.HEATED:55:9: error: request for member ‘writeEntry’ in ‘q’, which is of non-class type ‘Foam::scalar’ {aka ‘double’}
/home/dyfluid/OpenFOAM/dyfluid-v2006/run/bianhuaQ/0/SOLID/T.boundaryField.HEATED:55:24: error: ‘os’ was not declared in this scope; did you mean ‘cos’?