Heating water in a tank

[mkelly82]

Hello, 

I am trying to simulate water heating within a tank, such as water in a hot water cylinder or water in a kettle.  I wanted to start with a 2D simulation to reduce the complexity.  I have the tank as a surface which is defined as water, with temperature varying properties and an initial temperature of 15DegC.  There is a heating element within the tank  which generates the heat.  I know the dimensions of the element, but as a first approximation I wanted to model it as simply as possible.  I also know the total power input generated by the element in W, but not its surface temperature.  I have tried several methods.  At first I defined a total heating flux through the edges of a rectangle representing the element.  I also defined it as a surface and gave it a total heat generation.  In all cases the temperatures achieved in the water are much higher than expected.  I am very new to CFDesign and I am not sure what I am doing wrong.  From the simulation I want to be able to see how the tank heats up and natural convection currents within the volume.  At the moment I  don't believe the results I am seeing.  Any advice how to better tackle the problem, or any comment on what I might be doing wrong would be greatly appreciated.

Thanks.

[mdw9965]

Do you have a bc for heat loss to the environment? You might need a volume of air outside the container with small inlet velocity and an exit to include natural convection.