Time and Coordinate dependent Heat Load

[TeQie]

Hi there, i am enquiring anyone who knows about TIME dependent heat load. I am currently having a project of heating up rail (head hardening) and to achieve enough depth and hardness, I need to measurethe most suitable heat transfercondition to the rail head. The rail is moving in a conveyor while heated and cooled. In theory I have achieved what required but before the big investmentI am looking for some simulation to ensurethe theory works.


The question is:


1. Is the bulk temperature is the ambient temperature or the film temperature?


2. I would like to apply the time dependent heat loadcondition, using a symbolic (available function component), can anyone give me an example of using this? Any simple example will be so much appeciated.


3. Lastly, this is confusing me...The prescribed temperature as stated in PTC help file is the limit temperature of the entity...I dont get this and how Pro E asks me to input the temperature of the entity...Thermal boundary from my knowledge depends on the type of flow whether it is laminar or turbulent...and how can this differed from the thermal symmetry? Please advise

 

[Natewebb]

1. ambient


2. 1.1*time


3. a prescribed tempreature fixes a temperature, like a constraint in structure fixes displacment. This boundary condition is not driven by convection. It's not a limit, its a atificalially fixed temperature.

 

[TeQie]

Thanx so much, thats pretty much what Im looking for...However, If i read through the manual and tutorial from PTC, I dont see that Prescribed temperature is compulsory(different to structural analysis) unless you have a fix temperature input (varying heat flux) and it canbe ignoredwhen fix temp doesnt exist...correct me if im wrong...


Secondly, Can you help me clarify the equation problem with some advanced mathematics symbol e.g. cos(x). Whatdoes x represent? coordinate or time or something else?


For Your Interest In my analysis I would run a transient thermal analysis to represent the amount of heat into the rail head from time to time... Im going to heat up rail head with flame (flame hardening) to the head surface at constant heat fluxand the rail is moving horizontally...My interest is to find out at particular range of time I would get enough temperature (740degreesC) up to 6mm depth from the head then I need to air quench the head to 600degreesC in 10secs to obtain 340BHN hardness... I must determine the speed range that moves the rail horizontally as well as designing the cooling system (compressed air) to achieve perfect temp output and speed. I dont see that prescribed temperature is anyhow applied in my case except the contact region between the support and the rail but i assume it is ignorable.





Anyway your help is vry appreciated...Tell me anything if you have problem and I do my best to help.