[Audrius]

Hi everyone,

I have question. I'm trying to simulate natural convection in the spent fuel pool. For example I have a box which dimensions is: lenght and width 6,0 m, height 11,0 m.

Setup in Fluent 14.0 is:
General:
Solver - pressure-based
Time - steady
Gravity - Z axis -9.81

Models:
Energy - ON
Viscous - Standart k-e, Standart Wall Fn

Materials:
Fluid: water (boussinesq model 998,2 density; Cp 4182; Thermal Conductivity 0,6; Viscousity 0.001003; Thermal expansion coefficient 0,0002)

Cell Zone Conditions -> Edit -> Material name - water-liquid

Boundary Conditions (to types of wall: one wall heat - temperature 500K; others walls are only convection (Heat transfer coef. 2.5; Free stream temperature 293); OPERATING COUNDITIONS: operating pressure 101325 Pa, operating temperature 301K.

Solution methods: Scheme - simple; Gradient - Least Squares Cell Based; Pressure - Body force weighted; Momentum, Turbulent Kinetic Energy, Turbulent dissipation rate, energy is first order upwind

Solution Initialization - hybryd initialization

Run calculation - 1000 iterations

First question is - thats wrong with pressure? In the bottom of pool preassure should be about 2 bar.

Second queastion is - what way the water can be heated uo to 226 K (Water boiling near 2 bar pressure is about 110-120 Celsius and water can't be the biger temperature than ~110-120 Celsius?

Thank You!

[Audrius]

Please, help...

[sircorp]

Originally Posted by Audrius

Hi everyone,

I have question. I'm trying to simulate natural convection in the spent fuel pool. For example I have a box which dimensions is: lenght and width 6,0 m, height 11,0 m.

Setup in Fluent 14.0 is:
General:
Solver - pressure-based
Time - steady
Gravity - Z axis -9.81

Models:
Energy - ON
Viscous - Standart k-e, Standart Wall Fn

Materials:
Fluid: water (boussinesq model 998,2 density; Cp 4182; Thermal Conductivity 0,6; Viscousity 0.001003; Thermal expansion coefficient 0,0002)

Cell Zone Conditions -> Edit -> Material name - water-liquid

Boundary Conditions (to types of wall: one wall heat - temperature 500K; others walls are only convection (Heat transfer coef. 2.5; Free stream temperature 293); OPERATING COUNDITIONS: operating pressure 101325 Pa, operating temperature 301K.

Solution methods: Scheme - simple; Gradient - Least Squares Cell Based; Pressure - Body force weighted; Momentum, Turbulent Kinetic Energy, Turbulent dissipation rate, energy is first order upwind

Solution Initialization - hybryd initialization

Run calculation - 1000 iterations

First question is - thats wrong with pressure? In the bottom of pool preassure should be about 2 bar.

Second queastion is - what way the water can be heated uo to 226 K (Water boiling near 2 bar pressure is about 110-120 Celsius and water can't be the biger temperature than ~110-120 Celsius?

Thank You!

It is a case of Forced Convection Cooling. Pressure is with reference to Injection Point. (Similar to a pre-pressurized thank). set the reference pressure (in operating conditions) what ever is the pressure at the bottom of the cooling pool)

(I am not a expert but) Problem what I can see it your meshing zixe ? Such a large system, you need a massive computer to even create Meshing and months to process the modelling.

Good Luck

Shane

[Audrius]

Dear Sircop,

I have a very powerful compute cluster, so the mesh for my pool is about 30 million cels. Now my model looks like this:

My model is closed domain, so there is not the inlet and outlet pipes and the preasure in the operational conditions are selected like this:

By the way, maybe You have Forced Convection Cooling or Pre-pressurized tank tutorials?

Kind regards,
Audrius