Turbulent single-phase and two-phase semi-confined jet impingement heat transfer predictions
Turbulent single-phase, and two-phase (air and water droplets) jet impingement cases are calculated and analyzed for a variety of configurations and input and boundary conditions including jet Reynolds number (Re{sub w}), non-dimensional distance to target wall (H/W), inlet turbulence intensity, droplet size and injection velocity, and loading ratio. A finite control volume method is used with a two-layer turbulence model for solving the continuous phase flow parameters, and a trajectory approach is used to make two-phase flow calculations. For the single-phase cases examined, a secondary rise in Nusselt number was seen for higher H/W values or larger Reynolds numbers. This secondary peak diminishes and shifts to higher x/2H as H/W is decreased, consistent with the empirical data. Significant enhancement to heat transfer (up to over 3 times that of the corresponding single-phase case) was observed with the introduction of droplets. The significant contributors to the enhanced heat transfer were determined to be the heat-sink provided for the continuous phase, increased continuous phase mass flow rate due to vapor generation, and momentum-induced changes in the flow-field. Wall-to-droplet heat transfer and lift forces were not significant for the set of conditions examined. A reduction in loading ratio substantially reduced heat transfer, and variation of initial injection velocity for small droplets did not have an effect due to the relatively short aerodynamic response time.
- Research Organization:
- Dept. of Energy, Washington, DC (US)
- OSTI ID:
- 20002464
- Report Number(s):
- CONF-990805-; TRN: IM200002%%464
- Resource Relation:
- Conference: 33rd National Heat Transfer Conference NHTC'99, Albuquerque, NM (US), 08/15/1999--08/17/1999; Other Information: PBD: 1999; Related Information: In: Proceedings of the 33rd national heat transfer conference NHTC'99, by Jensen, M.K.; Di Marzo, M. [eds.], [1150] pages.
- Country of Publication:
- United States
- Language:
- English
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