ISSN Online: 2377-424X
International Heat Transfer Conference 5
LOCAL REDUCTIONS IN HEAT TRANSFER DUE TO BUOYANCY EFFECTS IN UPWARD TURBULENT FLOW
Abstrakt
Local deteriorations in heat transfer, similar to those reported for near-Critical fluids, have been observed during
non-boiling heat transfer to water at wall temperatures below 140 °C in upward flow at Reynolds numbers of 6 × 103 to 2.4 × 104 in a vertical, uniformly heated tube. Wall temperature peaks occur when GrB*/PrB0.4ReB3.4 > 4 × 10−5, the minimum heat transfer coefficient becoming insensitive to flow rate and tube diameter: NuF = 0.075(GrF*PrF)0.25 ± 10%. The distance for development of the first wall temperature peak is given by xp/d = 0.070 ReB3PrB1.2/GrB*.