Please see the attached file for the fully formatted problem(s).
1. A heated copper wire 1 mm in diameter is in a pool of water at 1 atm. What is the maximum heat flux (q/A)?
The temperature difference is related to the heat flux (q/A) by the following equation:
What temperature difference (which we'll call zTmax) is associated the
maximum heat flux (q/A)? What is the corresponding heat transfer coefficient for this maximum heat flux situation?
If the water were in the film boiling regime, what is the heat transfer coefficient corresponding to Tmax? Estimate the temperature difference T needed to achieve the maximum heat flux in the film boiling regime.
What is the required wire temperature?
How does this compare with the melting point of copper?
gives for cylindrical coordinates the following relationship which may be helpful in determining the maximum transfer coefficient for the maximum Q/A.
K= Q(ln(ro/ri)/2pLdelta T
Now the first part of this question requires we take into consideration that the phase of the water does not change in the heat exchanger. We have a phase change for water at 100C so the wire temperature cannot exceed 100C to prevent the film boiling. The initial ...
The heat flux and temperature of a copper wire are calculated. The temperature differences related to the heat flux is calculated.