DOI: 10.1615/ICHMT.1994.IntSympHetatTransTurb
ISBN Print: 1-56700-016-9
ISBN Print: 978-1-56700-016-0
The Computation of Convective Heat Transfer in a 180-Degree Pipe Bend
RESUMO
The paper presents computations of turbulent flow and heat transfer in a 180° circular-sectioned bend at a Reynolds number of 58,000. Fully developed pipe flow conditions prevail upstream of the bend entry. The aim is to examine the performance of near-wall models of turbulent heat and momentum transport in a strongly three-dimensional flow with severe streamline curvature. A finite-volume solver is used which employs an algebraic second-moment (ASM) model of turbulence within the fully turbulent region of the pipe. Across the near-wall sublayer two different turbulence models have been applied: a two-equation eddy viscosity model and an ASM scheme. The predicted local Nusselt number is particularly sensitive to the near-wall turbulence model. With the k-ε scheme, entry effects are correctly simulated but the heat transfer rates over the second half of the bend are substantially underpredicted. Use of the ASM scheme results in a significant improvement of the predicted heat-transfer rates.