Temperature dependant heat flux

[MNS747]

Hi All
I have an excel curve with the equation which came out manipulating the heat flux which is reducing with time and with the temperature increase. i.e. Heat flux decreases with time and the temperature increase.

I want to model this heat flux in Abaqus and want to model it as per the function of temperature. Means Abaqus should automate the process of decreasing heat load with the temperature increase not with the time. In other words the decreasing heat flux load should be a function of increasing temperature.

i know to create the tabular Amplitude but this allows only the input of heat flux against time. However i have created an analytical field and input the obtained equation from excel which was
y = 4E-06x2 - 0.0028x + 0.5309 (3rd order polynomial with X being temperature and Y being the flux)
Now I dont know how i can input temperature in above equation in Abaqus. I appreiciated if i get any answers to this.
Regards

 

[MNS747]

Hi All
Sorry for posting this topic again as just trying to be more clearer.
I am trying to model the flux from the bearings which reduces with the temperature increase. i.e. the flux is totally dependant on the temperature. Do I need the user subroutine *DlOAD to do this? if so is there any possibility that any one can help me starting it as i am new to the scripting. thanks in advance

Regards

 

[DanStro]

I can't say that I've done anything like this but it looks to me like DFLUX would be the correct choice. FLUX(2) is the change in flux w/Temp.

HTH
Dan

 

[corus]

DFLUX would be the way if you have fortran, but if the flux depends on the temperaure (presumably the surface temperature) then you could define a heat transfer coefficient such that the term h.(T-Ta) is equivalent to your flux, with transfer coefficient,h, set as temperature dependent so that your h.(T-Ta) is equivalent to the cubic.

corus

 

[MNS747]

hi Corus
thankyou for your reply. let me explain the problem. the bearing is rotated for an hour and the temperature is measured at the surface of the housing where the bearing is enclosed. At the surface, the temperature was measured as ramping up quickly and after half an hour it starts to get stabilized. Now using the temperature data, the heat flux was calculated at every 10 sec hence gave me the decay curve i.e. the flux was decreasing due to temeprature stabilization or vice versa. My requirement is to model it automatically so that the Flux should see the temeprature i and lower itself later. I was able to obtain an equation which is mentioned above as I dont want to use tabular data. It seems DFlux is the right choice. As per your recommedation for the coefficient h, again i have to develop the tabular data for the temeprature and defining different h at different temperatures. Now what do you prefer, shall i go for the DFlux routine or coefficient h.
Thanks and appreciated
regards

 

[corus]

If you have fortran then DFLUX is the much easier option than having to fiddle about with deriving coefficients for h.


corus

 

[MNS747]

Thanks Corus.Your help is greatly appreciated
Regards