Turbulent Flow and Heat Transfer in the Entrance Region of a Parallel Wall Passage

Abstract

Measurements of boundary layer development and heat transfer were made in the entrance region of a parallel passage and compared with a computer solution based on the law of the wall. Little difference was found between the heat transfer, both measured and predicted, with a developing flow and that predicted with a fully developed flow. The experiments also show that boundary layer parameters, such as momentum thickness, do not approach their fully developed values asymptotically.

Feeding anatomy, filter-feeding rate, and diet of whale sharks Rhincodon typus during surface ram filter feeding off the Yucatan Peninsula, Mexico

“…At these Reynolds numbers the flow is very likely turbulent, but the nature of that turbulence is uncertain. In the initial length of a parallel channel, such as the parabranchial chamber, the flow is characterized by highfrequency, small-scale turbulence and reduced boundary layer thickness (Byrne et al, 1969). However, after this initial length, the flow is dominated by low-frequency, large-scale turbulence and the boundary layer extends the entire channel width (Clark, 1968;Moin and Kim, 1985).…”

Hybrid solution of the averaged Navier-Stokes equations for turbulent flow

“…The tabulation of the longitudinal velocity component at the centerline is presented here, in order to produce a set of reference results in the comparisons that follow, against experimental and previous numerical contributions. Figures (2.a,b) bring a comparison of the present integral transform results, under the full Navier-Stokes formation and the algebraic turbulence model in Richman and Azad (1973) and Taylor et al (1977), and the experimental results of Byrne et al (1969±70), for the longitudinal velocity component pro®les at different axial positions and Re 7X0 Â 10 4 . Also, some sample results from previous work under the boundary layer formation are shown, such as the integral transform implementation in Pimentel and Cotta (in Press), which employs the algebraic turbulence model of Cebeci and Smith (1974), and the ®nite differences solution with k À e model proposed in Zaparoli (1989).…”

“…In this case, the experimental results of Dean (1972) are employed in the comparisons, complemented by the boundary layer integral transform results in Pimentel and Cotta (in press Figures (4.a,b) show the evolution of the centerline longitudinal velocity component along the channel dimensionless coordinate, X, respectively, for Re 7X0 Â 10 4 and 1X0 Â 10 5 . Besides the experimental results of Byrne et al (1969±70) and Dean (1972), alternative simulations with more involved turbulence models are presented, extracted from Pimentel and Cotta (in press), Bradshaw et al (1973) and Emery and Gessner (1976). Clearly, the very simple turbulence model utilized, and detailed in appendix A, can adequately reproduce the centerline velocity at regions close to the channel inlet and as the fully developed region is approached.…”

Prediction of laminar and turbulent flow heat transfer in annular passages

“…4.24 the present predictions for skin friction coefficients are compared with the data of Dean [147] and Byrne et al [148], along with the predictions of [111] and [150]. The wall shear stress values in [148] The effect of bridging (Model B) on flow development was also studied. In these cases, the turbulent viscosity profile was bridged of [147] and [148] along with the prediction of Model A are also shown.…”

“…The wall shear stress values in [148] The effect of bridging (Model B) on flow development was also studied. In these cases, the turbulent viscosity profile was bridged of [147] and [148] along with the prediction of Model A are also shown.…”