Critical heat flux on a flat plate in a pool of subcooled liquid helium

Abstract

Critical heat flux (CHF) on a flat plate in a pool of liquid helium was measured for bulk liquid temperatures ranging from saturation temperature down to 1.8 K under pressures of 101.3 and 130 kPa. Four test plates 10 mm wide×40 mm long×0.1 mm thick, made of Manganin were used. Test plates were pasted on a Fiber-Reinforced-Plastic (FRP) plate 4 mm in thickness. The test plates were supported with the heated surface upward (θ=0), θ=π/2, θ=3π/4 and downward (θ=π), respectively. Clear dependence on the supporting angle, θ, was observed for the critical heat fluxes (CHFs) in He I. The CHFs become gradually lower with the increase in θ to around π/2 and decrease significantly with further increase in θ. The CHFs for each supporting angle increase with the increase in subcooling. The CHFs become significantly higher with the bulk liquid temperature becoming lower than the lambda temperature, and the dependence on the supporting angle diminishes. Correlation of CHF in He I including the effects of supporting ang...