Can you please tell me how to shose the boundry conditions in a fixed bed combustion of coal. Thanks

(1). If you don't know what to do with the boundary conditions, then try to simulate it as if you are running the test. (2). In the testing, you will have to know something, or measure something, and that will give you the boundary location and conditions. (3). Apparently, you can't specify the condition at the surface of the coal. It is burning and the surface is most likely irregular. (4). So, you need to define the inlet conditions and location away from the coal bed. You also need to model the coal bed so that you can simulate the coal burning.

Hallo

actually fixed bed reactors are very important in chemical engineering. There is a vast amount of research articles in almost any chemical journal. From such sources you can see how the equations look like, and set up your own equations that describe the funktion your a fixed bed. for example: do you have to calculate axial diffusion in your fluid?

By the way do you use one , two or three dimensional equations? There are some very important approximations like the Vortmayer description of the flow field in a fixed bed reactor, that might be quite usefull to you.

best regards,

Jannis