Measurement on Nusselt number of regenerator wire meshes by cylindrical probe
- Ashikaga Inst. of Tech., Tochigi (Japan). Dept. of Mechanical Engineering
- Nihon Univ., Tokyo (Japan)
The regenerator is an important element in Stirling engines. As a regenerator element, a fire-hardened layer of wire mesh became popular for Stirling engines. However the fire-hardened layer of wire mesh is expensive. Recently packed wire mesh has been used widely in Japan, however basic performance like flow resistance and heat transfer ratio, has not been clarified yet. The authors measured performance of flow resistance and presented the results in last year`s IECEC conference. In the present study, a new method to estimate the Nusselt number of wire meshes in oscillating flow is proposed and reported. This method employs a cylindrical probe having two thermocouples in the axis symmetry direction. The present method has a feature that temperature variation in oscillating flow condition can be estimated without expensive instrument for unsteady measurement. It became clear that the measured Nusselt numbers of usual meshes are from 45% lower to 30% higher than the empirical equation of previous study. The Nusselt number of packed wire mesh became about 1/6 of the equivalent layer of usual mesh. These results shows that a rough estimation of performance of heat transfer is possible by the present method.
- OSTI ID:
- 474393
- Report Number(s):
- CONF-960805--
- Country of Publication:
- United States
- Language:
- English
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