[pratikmehta]

Hello Friends,

I am trying to perform a simulation for ice melting

Here is the Problem definition:

I have a aluminium hollow pipe ( 1mm thickness ) . Through this pipe water at 80 C is flowing at constant flow rate . Re number is about 20K
The ice deposition over this pipe is about 2mm thick .

My quest is to know how much time does it take for the ice at -5 C gets converted to water at 5 C . I just need to know when does water reach 5C.


What I have done so far:

I have got geometry and meshed it .I have the fluid domain ( water )and solid domain ( Ice ) .I am using CFX 12.1v. Material in fluid domain is water & material in Ice domain is user created material as CHT solid & thermodynamic state as solid.

My doubts,,,
1) How should I treat the interface ??. Should I keep it as conservative interface flux as the boundary condition and should I create a thin wall of 1 mm aluminium ,so as to save my meshes to aviod the extra physical 1mm thickness of the pipe.

2) Variables like Density, Thermal conductivty & Sp heat capacity as all function of temperature. Regarding the thermal conductivity & density I have used step function CEL expression that will suitably feed in the right number at the existence of ice or water. My biggest worry is to specify Cp variation as the ice start to heat up from -5C .

I need to know how should I specify Cp that will consider the Cp of Ice from -5C to -1C approx 2kJ/KgK , then it must consider Cp as 166kJ/KgK frmo -1C to +1 C and later from 1C onwards Cp as 4kJ/KgK .

I tried to use the step function in order to get this variation but could not get it correct.

So how would you suggest me to go forward .


Thanks for your suggestions

Best regards
Pratik