Meeting No.7: Target Cell simulation #2

This week I continued my work on the simulation of the gas movement inside the 3He target. This time I focused my self on the gas behavior in the pumping chamber:

a.) I assumed that there is a constant temperature (230 deg C ) all all around the pumping chamber, while the rest of the cell is at the constant temperature of 40deg C. The parameters of the gas inside the simulated cell are still not exact, but are very close to the true He values.

b.) I again considered the Navier-Stokes equation of the movement of the viscous fluid and the model for the conduction and convection of the heat - I combined these two models together.

c.) To do this simulation I used the Comsol Multiphysics software package (uses FEM)

Simulated temperature profile:

Vertical Profile:

1.) 2.)

Horizontal Profile:

3.) 4.)

Simulated density profile:

Vertical Profile:

5.) 6.)

Horizontal Profile:

7.) 8.)

Simulated velocity profile:

Vertical Profile:

9.) 10.) 11.) 12.)

Horizontal Profile:

13.) 14.) 15.) 16.)

Problem:

I am having problem with the pressure inside the target cell. I am still learning how to convince Comsol to properly consider pressure. At the moment I believe that this might solve my problems with boundary conditions and enable me to simulate the whole cell. So far I can not make a simulation where I demand a "no slip" condition in all the wall - the simulation explodes. This is important because I can not belive the simulation unless I get reasonable results for the pressure inside the cell.

To-Do:

a.) Try to make a 3D simulation.
b.) Solve the problems with the pressure inside the cell and try to do the simulation of the whole cell - It appears to be very difficult.
Last Modified: 10/05/09