Problem with initial condition temperature in a thermal analyses

[paulis]

Dear all

Hi , how are you ?? well,I have some new problem ,I´ve been working in food thermal analysis applied in a meat muscle during a cooking process in a retort ( a retort is similar to oven but this one is with air and the retort cooks with water cascade ).

My simulation is divided in 3 steps,

step 1: a ramp up ,load 20 ºC to 75ºC
step 2: holding, load 75ºC
step 3: a ramp down , load 75 a 20ºC

My problem is that i can´t manage to put my inicial condition of a muscle and the retort at the same time so I try to explain what happennig to me,

The muscle must be at 0ºC ( because in a real life in the laboratory I take of from the frigde the piece of meat at that temperature) and the retort start cooking at 20ºC which is the natural environment condition and then raise to 75ºC during normal operation.

What I allways used in Abaqus is load condition. I thought that abaqus set 0ºC for my inicial condition of the muscle. So in step 1 I put 20º to simulate the retort temperature , but I discovered that my muscle and the retort are and the same temperature 20ºc when the process starts and this is no right.

could you please give me some advice?

thanks in advanced

Paulis =)

 

[GNicholson]

Paulis,

Quick question, are you using "Dynamic, Temp-disp, Explicit" for the step type?

Regards.
Gordon

 

[corus]

I would assume that the analysis is standard using transient heat transfer, altough you've not mentioned the time period for each step. In CAE use prescribed displacement and set the temperature of each part to whatever value it is initially, and set it for the initial step.

corus

 

[paulis]

hello again! yes, you are right , I missed the step times!I I´m sorry!

My simulation in ABAQUS 6.7/CAE version is divided in 3 steps

increment size 0.002

step 1: 0.012 a ramp up ,load 20 ºC to 75ºC
step 2 0.076 holding, load 75ºC
step 3: 0.026 a ramp down , load 75 a 20ºC

so please what should I do so as to have my muscle at 0ºC at initial time? Do i have to use stefan boltzman 5.67 e-11at the beggining of the model atributes and absolute zero??

Gnicohlson , I don´t use Dynamic, Temp-disp, Explicit" but thanks for asked.

thanks in advanced

paulis =)

 

[amubashar]

Hi

To define an initial temperature for a part in CAE, in model tree, choose Predefined Fields -> Other -> Temperature and provide a value for the Initial step.

Regards

Aamir