[mattyg88]

Good Afternoon,

To refresh your memory, I am a 3rd year MEng civil engineering student from the uk. I am currently working on my 30 credit project which is to analyse and design a contact mixing tank for wastewater treatment works.
I have generated my geometry and mesh for the tank in ansys workbench, inputted the boundry and flow conditions in cfx-pre, ran it in cfx-solver and post processed the results.
The results I feel I am getting for the pressures on the walls are very unrealistic with the average pressure being around 50Pa and the absolute pressure at 1.01E05 Pa for all the nodes on the outside mesh of the tank. I am aware I should be seeing pressures that are very similar to the static pressure caused by the weight of the water (static pressure = water density * gravity * hydraulic column = 1000 kg/m3 * 9.8 m/s2 * 3m = 29.43 kPa).
I have tried changing small things in ansys-pre but I keep getting the same results and its as if my simulation is not considering the weight of the water however stupid that sounds. My outlet of the tank is set at a position below the inlet so my flow should exit the tank via the outlet with zero energy costs. I have set my outlet to a static pressure of 0, is this correct? I also chop and change my wall boundrys from free slip to no slip but this doesnt seem to change the results.
If anybody has any idea of how to alter my system to produce some realistic results I would be extremely grateful .

Many thanks for your time,

Matt