I can create the object for you but I can't simulate it for you.

1. The way to sketch it is to draw a box and then and radius the corners to a full half circle. - OR- you can just draw an oval using the oval tool.

2. dimension the length and width of the oval in the sketch.

3. create an offset to the wall thickness

4. extrude all of the sketch up to the bottom wall thickness.

5. extrude just the otter perimeter up to the top height.

6. Use can also user the shell tool on the full extrude if you would prefer.

Did any of these steps work for you ?

Also please post which software you are using for the pressure simulation as SolidWorks has very limited capabilities without the extra modules, especially in the student versions.

Still waiting to hear if you solved it or have any other questions . . .