Inlet and outlet velocities and short circuiting

[ashtree]

I am in the middle of a debate regarding short circuiting on water storage reservoirs.

Do high inlet and outlet velocities encourage short circuiting or reduce short circuiting? Do high velocities increase or reduce stagnant areas in the tank?

To give you an idea of the magnitude of the tanks these have a theoretical HDT of about 3 days at average flow.

My theory is that if inlet and outlets are close together then a high inlet velocity is good but maybe a low outlet velocity is required. This will tend to force water away from the inlet position and perhaps mix the rest of the tank contents.
But if inlet and outlet are well apart both should be low velocity to discourage short circuiting straight across the tank.

Does any one have an opinion?

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[mk3223]

You could be right.
IMO, in additional to the velocity, the real degree of the short circuiting may also be depended on other physical properties of the fluid.
If the short circuiting is a concern, one may consider to use the mechanical equipment to increase the fluid circulation.

 

[bimr]

Depends somewhat on the shape of the tank, temperature, etc. One of the CFD models is probably the best approach to see what is going on in the tank.

Link

 

[ashtree]

Thanks for your advice.
bimr, the link was useful.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[JStephen]

Another option, based on using inflow water for mixing:

https://www.redvalve.com/tideflex/tideflex-products/tideflex-potable-water-mixing-systems-tms

I believe CBI also has a system with similar goals but considerably different details.
I've seen these systems used on a tank or two, but have no knowledge of the operational details, how much of a problem there was, how good the solution worked, etc.