class 7 - Transient Conduction: The Lumped Capacitance...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
Transient Conduction: The Lumped Capacitance Method Chapter Five Sections 5.2 thru 5.3 Class 7
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
What kind of situation is transient conduction? A solid experiences a sudden change in its thermal environment Quenching Charging Lumped capacitance Assume temperature is spatially uniform at any instant during the transient process Therefore we assume no temperature gradients
Background image of page 2
For this situation, what is the energy balance? g out in st st E E E t dE E + - = I II III IV a)I and II b)I and III c)I, II and III d)I and IV e)II, III and IV
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
How do we use the energy balance to find our lumped capacitance approach?
Background image of page 4
Define a thermal time constant:
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Define a thermal time constant: What will happen if we increase R t ? a)A solid will respond more slowly to changes in its thermal environment b)A solid will respond more quickly to changes in its thermal environment c)The R t does not affect the response – only the lumped thermal capacitance
Background image of page 6
To determine total energy transfer Q after some time :
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Since –Q = ΔE st a)For quenching Q is positive and the solid experiences a
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 15

class 7 - Transient Conduction: The Lumped Capacitance...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online