Heat Transfer to Molten Lead-Bismuth Eutectic in Turbulent Pipe Flow

Abstract Experimental heat-transfer results for molten lead-bismuth eutectic are presented for turbulent flow in a ¾-in. 18-gage mild-steel tube with constant heat flux. Validity of the measurement technique is established indirectly by identical tests with water which agree with the predicted heat-transfer performance for that fluid. Results for lead bismuth are correlated for the Peclet modulus range of 200 to 5000 over a Prandtl modulus range of 0.020 to 0.046 and Reynolds-number range of 7500 to 170,000. The resulting Nusselt moduli are 25 to 35 per cent lower than the prediction of Lyon-Martinelli momentum theory for turbulent flow. Local heat-transfer coefficients at the start of the heated section reveal that the thermal entrance length is approximately 30 pipe diameters.