Turbulence modeling for high-lift multi-element airfoil configurations | Posted on:2005-01-28 | Degree:Ph.D | Type:Dissertation | University:University of Toronto (Canada) | Candidate:Godin, Philippe | Full Text:PDF | GTID:1452390008984610 | Subject:Engineering | Abstract/Summary: | | This study provides a detailed comparison of two turbulence closures for aerodynamic flows around high-lift airfoils; the first based on turbulent viscosity and the second on the algebraic Reynolds-stress approximation. A detailed analysis of their derivation helps shed light on their inherent limitations in predicting complex flow phenomena such as confluent boundary layers and flow separation found in typical take-off and landing conditions.; Amongst the turbulent viscosity models coded and studied are the Spalart-Allmaras, Baldwin-Barth, Wilcox k - o and Menter's Shear Stress Transport model. A parameter study based on different pressure-strain correlations and dissipation models (or near-wall treatment) is included when studying the algebraic Reynolds-stress models for both the explicit (EARSM) and the more traditional or implicit (IARSM) forms.; One of each of the following categories: one-equation, two-equation, IARSM and EARSM is selected and compared on several low-speed high-lift configurations. Comparisons to experimental data for both mean flow and turbulence quantities are provided for all cases studied.; Results are generally very promising and of sufficient accuracy for engineering interest. Overall, the study indicates that for flows around low-speed high-lift airfoils, the algebraic Reynolds-stress construct does not represent a higher level of description than the eddy viscosity models since it fails to improve on accuracy. The basic underlying assumption of weak-equilibrium in algebraic Reynolds-stress models is outperformed by well calibrated eddy-viscosity models. | Keywords/Search Tags: | High-lift, Algebraic reynolds-stress, Turbulence, Models | | Related items |
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