12-06-2012, 01:58 PM
Transient Thermal Analysis of a Fin
[attachment=24189]
A cylindrical copper fin conducts heat away from its base at 1000C and transfers it to a surrounding fluid
at 250C through convection. The convection heat transfer coefficient is
. The copper has a
thermal conductivity (k) of 398
, a specific heat (Cp) of 385
, and a density of 8933
. Determine
the following:
(a) the time to reach steady state
(b) the steady state temperature distribution (using a transient analysis)
© the temperature distribution after 50 seconds
(d) the animated history of temperature in the fin over time
(e) the steady state heat transfer rate through the base of the fin (using a transient analysis)
(f) the steady state temperature distribution and heat transfer rate through the base using a
steady state thermal analysis
For the transient analysis, we will assume that the fin has an initial temperature of 250C. At time t=0,
heat will begin to flow from the base into the fin where some of the heat is stored (hence the need for
the specific heat and density) and some of it is convected away. After a period of time, the temperature
distribution in the fin will become steady. Steady state solutions require that the system of equations
defining the model be solved only ONCE, while transient solutions require a new solution for each time
step. For example, ANSYS will determine the temperature distribution at t=0.1 s based on the initial
conditions. Next, ANSYS will determine the temperature distribution at t = 0.2 s based on the
temperature distribution at t=0.1 s (and so on). Solution accuracy is a function of the size of the time
steps as well as characteristics of the mesh.
[attachment=24189]
A cylindrical copper fin conducts heat away from its base at 1000C and transfers it to a surrounding fluid
at 250C through convection. The convection heat transfer coefficient is
. The copper has a
thermal conductivity (k) of 398
, a specific heat (Cp) of 385
, and a density of 8933
. Determine
the following:
(a) the time to reach steady state
(b) the steady state temperature distribution (using a transient analysis)
© the temperature distribution after 50 seconds
(d) the animated history of temperature in the fin over time
(e) the steady state heat transfer rate through the base of the fin (using a transient analysis)
(f) the steady state temperature distribution and heat transfer rate through the base using a
steady state thermal analysis
For the transient analysis, we will assume that the fin has an initial temperature of 250C. At time t=0,
heat will begin to flow from the base into the fin where some of the heat is stored (hence the need for
the specific heat and density) and some of it is convected away. After a period of time, the temperature
distribution in the fin will become steady. Steady state solutions require that the system of equations
defining the model be solved only ONCE, while transient solutions require a new solution for each time
step. For example, ANSYS will determine the temperature distribution at t=0.1 s based on the initial
conditions. Next, ANSYS will determine the temperature distribution at t = 0.2 s based on the
temperature distribution at t=0.1 s (and so on). Solution accuracy is a function of the size of the time
steps as well as characteristics of the mesh.