Microscopic and macroscopic fin-collar effects in the prediction of finned-tube contact
This work developed a methodology that will enable the future development of a generalized correlation of thermal-contact conductance for the test samples of plate finned tubes (coils). This was accomplished by determining the local (microscopic) contact conductances and the fin-collar (macroscopic) resistances of coils. These two parameters were not taken into account while formulating the previous correlation. Experimental data for test samples of coils operating under vacuum were obtained from recent American Society of Heating, Refrigeration, and Air-Conditioning Engineers' sponsored projects. These data were utilized to correct the prediction of thermal-contact conductance of the fin by taking into account the effect of fin collars. The only available hypothetical contact pressure distribution in the literature was modified to take into account of a variable local pressure and the interference at the interface of tube and the fin. In turn, this pressure distribution was related to the microscopic contact conductance of the fin. Steady-state heat conduction through the tube to a fin collar resulted in a mixed boundary-value problem. The software Interactive Thermal Analysis System (I/TAS) available for use with a microcomputer based on the nodal method was used to solve a set of these problems. This enabled the determination of the macroscopic thermal contact conductance of fin collars.
- Research Organization:
- Missouri Univ., Rolla (USA)
- OSTI ID:
- 7146788
- Country of Publication:
- United States
- Language:
- English
Similar Records
A new method to estimate the thermal contact resistance in finned-tube heat exchangers
Solving macroscopic and microscopic pin-fin heat sink problems by adapted spectral method