Hi Dio,

On 11/23/2017 03:22 PM, Dio Dwianto wrote:

Hi Robert,

thanks for your help! That finally solved it, apparently the initial condition was set to distribute temperature between -2 and 2 degrees while I set the temperature at 20 degrees Celcius.

Now I'm trying to add another boundary condition to the equation to take into account the convective heat transfer that's going on the surface. I tried to use dw_surface_dot, but I'm not sure which parameter I shoud use. This is what I wrote so far:

[image: Inline image 1]

with coef.val I meant the convective heat transfer coefficient [W/m^2K]

The dw_surface_dot needs to be used as follows:

equations = { 'Temperature' : """dw_volume_dot.i.Omega(Omega.capacity, s, dT/dt) + dw_laplace.i.Omega(Omega.conductivity, s, T) - dw_surface_dot.i.Omega(coef.val, s, T) = 0""" }

Note also, that there is no ds/dt in the dw_volume_dot term.

But all I get was an error message:

[image: Inline image 2]

Can you tell me what I should do to fix this? Also do I have to add another solver to solve the convective heat transfer problem?

You might want to use dw_surface_integrate term to apply a given heat flux on a boundary - see [1] for a usage example. No other solver needs to be added.

[1] http://sfepy.org/doc-devel/examples/diffusion/poisson_neumann.html

r.