Experimental and Numerical Investigation of Electra KrF Laser Hibachi Foil Cooling with a Near-Wall Planar Jet
- 67 Downloads
Repetitively pulsed operation (5 Hz) of the electra gas laser requires sufficient cooling of the transmission foils, which separate the vacuum diodes from the laser cell and is subject to excessive heat from the attenuation of electron beams. A new method adopting a near-wall, high-speed planar jet was proposed for the protection of the hibachi foil by enhanced convection heat transfer. The jet flows upwards and is parallel to the hibachi foil. Bench-top experiments simulating a single foil span between two neighboring supporting ribs were conducted. Jet velocities and surface heat fluxes were varied. Experimental Nusselt numbers were correlated as dependent on jet Reynolds number and normalized distance from the jet exit. CFD simulations were also performed, where good agreement was observed between the experiments and simulations. The study shows that the planar jet enhances heat transfer from the surface but with decreasing heat transfer coefficients downstream, which indicates that the foil is not cooled uniformly with a single planar jet.
KeywordsInertial fusion energy Gas laser Hibachi cooling Heat transfer enhancement Planar jet
Financial support by the Naval Research Laboratory is acknowledged.
- 3.F. Hegeler et al., in Proceedings of 15th IEEE International Pulsed Power Conference (Monterey, California, June 13–17, 2005)Google Scholar
- 5.P. Burns et al., Fusion Sci. Technol. 56, 346 (2009)Google Scholar
- 6.V. Novak et al., Fusion Sci. Technol. 47, 610 (2005)Google Scholar
- 7.V. Novak et al., Fusion Sci. Technol. 52, 483 (2007)Google Scholar
- 8.B. Lu et al., Fusion Sci. Technol. 56, 441 (2009)Google Scholar
- 9.P.M. Burns et al., Fusion Sci. Technol. 56, 341 (2009)Google Scholar
- 10.R.J. Goldstein, in Advances in Heat Transfer 7, 321, ed. by T.F. Irvine Jr, J.P. Harnett (Academic Press, New York, 1971)Google Scholar
- 12.J. Zhou, M. Salcudean, I. Gartshore, in Near-Wall Turbulent Flows (Elsevier Science Publisher, The Netherlands, 1993), pp. 377–386Google Scholar
- 14.A. Lefebvre, in Gas Turbine Combustion (Taylor and Francis, London, 1999), pp. 289–297Google Scholar
- 15.C. A. Cruz, A. W. Marshall, in Proceedings of 40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit (Fort Lauderdale, Florida, July11–14 2004)Google Scholar