Turbulent Flow Past a Surface-Mounted Two-Dimensional Rib

Abstract

The ability of the nonlinear k–ε turbulence model to predict the flow in a separated duct flow past a wall-mounted, two-dimensional rib was assessed through comparisons with the standard k–ε model and experimental results. Improved predictions of the streamwise turbulence intensity and the mean streamwise velocities near the high-speed edge of the separated shear layer and in the flow downstream of reattachment were obtained with the nonlinear model. More realistic predictions of the production and dissipation of the turbulent kinetic energy near reattachment were also obtained. Otherwise, the performance of the two models was comparable, with both models performing quite well in the core flow regions and close to reattachment and both models performing poorly in the separated and shear-layer regions close to the rib.

Numerical study of turbulent flow over two-dimensional surface-mounted ribs in a channel

“…To test the accuracy and validity of the numerical computations, a case of a turbulent duct flow over a surface-mounted two-dimensional square rib (B/H= 1) is computed and compared with the previous study of Acharya et al [3]. Table I shows all relevant parameters in the experiments of Acharya et al [3] and the corresponding values used in present model.…”

“…The inlet boundary is located at 15 rib heights upstream of the obstacle. To compare the results with experimental data of Acharya et al [3], their inlet flow conditions were used for the specification.…”

“…Antoniou and Bergeles [2] measured the mean velocity and turbulence intensity along with integral properties of the developing flow to examine the region behind a two-dimensional surface-mounted prism of varying length after reattachment. In using a conventional fiber optic laser-Doppler anemometer (LDA) system, Acharya et al [3] measured the flow of mean velocities and Reynolds stresses in the upstream and downstream recirculating regions of a separated duct flow past a two-dimensional surface-mounted square rib. In the numerical investigations, most of the studies attempted to improve the turbulence models to simulate the turbulent transported quantities.…”

“…In the numerical investigations, most of the studies attempted to improve the turbulence models to simulate the turbulent transported quantities. It included the studies of Acharya et al [3], Durst and Rastogi [4] and Benodekar et al [5]. To account for the near-wall effects in using the non-linear k-m model to simulate the turbulence quantities, the wall function approximations are used in these studies.…”

A 3D-PIV System for Gas Turbine Applications

“…1), and this facility has been used by the co-PIs to study heat transfer in the coolant channels with rotation {Hibbs Eliades et al, 1999) and without rotation (Hibbs et al, 1998;Hibbs et al, 1999). Velocity and temperature measurements, and RANS computations in the stationary frame have also been reported by the PI (Acharya et al 1994.…”