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Heat transfer equation - formulation

  1. Mar 19, 2012 #1
    Hi, I have a device which is heated from inside by constant heat (let's say by Joule's heat - UIt). Some heat causes temperature rise of the device, some is lost into surroundings through device's surface. I measured how temperature of the device varies with time and I want to calculate constants like heat capacity of the device and heat loss coefficient.

    But I'm not sure whether my equation is correct:

    dQ = CdT1 + γ(dT2)dt

    C - heat capacity of the device
    γ - heat loss coefficient
    dt - time differential
    dT1 - temperature differential (of the device per dt)

    I'm confused about last expression in the equation: What does dT in the expression γ(dT2)dt mean? Is it the same as dT1 or is it rather instantaneous temperature of the device minus temperature of surroundings?
  2. jcsd
  3. Mar 21, 2012 #2
    Anyone? I just need in what form/terms we express heat loss...
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