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Book Improved Reynolds Stress Modeling for Adverse Pressure Gradient Turbulent Boundary Layers in Industrial Aeronautical Flow

Download or read book Improved Reynolds Stress Modeling for Adverse Pressure Gradient Turbulent Boundary Layers in Industrial Aeronautical Flow written by Gustave Sporschill and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work seeks to improve the prediction of turbulent boundary layer flows under adverse pressure gradients (APG) encountered in the aeronautical industry, especially towards the trailing edge of wings. Indeed, the inaccurate prediction of such flows results in inaccurate predictions of aircraft performance and of the limits of the flight domain. To reduce the design margins and enable optimal aircraft geometries, the reliability of turbulence models in APG boundary layers has to be improved.The relevance of second-moment closures of the RANS equations, also called Reynolds-stress models (RSM), aiming at reproducing more accurately the physics of the flow, is therefore assessed for industrial use. Three Reynolds-stress models that differ in their near-wall modelling and in their length-scale providing equation, namely the EB-RSM, the SSG/LRR-omega RSM and the SSG-omega ATAAC RSM, are first benchmarked on two academic test cases, a flat plate and the APG boundary layer at equilibrium of the Skåre & Krogstad experiment, against the Spalart-Allmaras model and the reference data. These academic cases highlight the fundamental differences between the models and their impact on the profiles and integral quantities of the boundary layer. In particular, the Reynolds-stress profiles and the turbulence budgets in the flat plate test case demonstrate the effectiveness of near-wall modelling. However, the Skåre & Krogstad test case shows the necessity to improve the prediction of velocity profiles in the log region and of skin friction in strong APG flows, despite an excellent prediction of the boundary layer growth.A correction for the log-law region, corresponding to a local recalibration of the model constants in APG regions, is first explored to ensure the correct velocity gradient in APG log layers. The correction is investigated with the Spalart-Allmaras model using a NACA 4412 test case. Despite satisfactory results, the correction is shown to be difficult to generalise to other models and that its impact on the flow prediction is limited to low-Reynolds-number cases, thus restricting its relevance for the aeronautical industry.The two-equation eddy-viscosity models and RSMs are shown to be incompatible with the square-root layer, which progressively grows at the outer end of the log layer in APG boundary layers. A correction locally introducing a pressure-diffusion term is therefore investigated analytically and assessed on the RSMs considered using the Skåre & Krogstad test case. A new model, the EB-RSM-dP, is here defined as a corrected version of the EB-RSM and exhibits improved predictions regarding the velocity and Reynolds-stress profiles and the boundary layer quantities.The standard and corrected RSMs are compared to the Spalart-Allmaras model on an application case, the Common Research Model, representative of a commercial aircraft, and demonstrate the relevance of such models for the aeronautical industry with improved pressure distribution on the wing and reduced errors in the drag-due-to-lift predictions. The square-root-law correction is here validated with the SSG/LRR-omega-dP of Knopp et al. (2018) and the newly developed EB-RSM-dP, and shows significant improvement of the aerodynamic load on the wing, and of both the lift and drag predictions for the highest Reynolds number configuration, compared to the uncorrected models. This study also highlights the strong impact of the activation region of the correction on the results.

Book Differential Reynolds Stress Modeling for Separating Flows in Industrial Aerodynamics

Download or read book Differential Reynolds Stress Modeling for Separating Flows in Industrial Aerodynamics written by Bernhard Eisfeld and published by Springer. This book was released on 2015-03-24 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents recent progress in the application of RANS turbulence models based on the Reynolds stress transport equations. A variety of models has been implemented by different groups into different flow solvers and applied to external as well as to turbo machinery flows. Comparisons between the models allow an assessment of their performance in different flow conditions. The results demonstrate the general applicability of differential Reynolds stress models to separating flows in industrial aerodynamics.

Book Computation and Comparison of Efficient Turbulence Models for Aeronautics European Research Project ETMA

Download or read book Computation and Comparison of Efficient Turbulence Models for Aeronautics European Research Project ETMA written by Alain Dervieux and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains contributions to the BRITE-EURAM 3rd Framework Programme ETMA and extended articles of the TMA-Workshop. It focusses on turbulence modelling techniques suitable to use in typical flow configurations, with emphasis on compressibility effects and inherent unsteadiness. These methodologies are applied to the Navier-Stokes equations, involving various turbulence modelling levels from algebraic to RSM. Basic turbulent flows in aeronautics are considered; mixing layers, wall-flows (flat-plate, backward-facing step, ramp, bump), and more complex configurations (bump, aerofoil). A critical assessment of the turbulence modelling performances is offered, based on previous results and on the experimental data-base of this research programme. The ETMA results figure in the data-base constituted by all partners and organized by INRIA

Book Workshop on Engineering Turbulence Modeling

Download or read book Workshop on Engineering Turbulence Modeling written by and published by . This book was released on 1992 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Turbulent Boundary Layers

Download or read book Turbulent Boundary Layers written by Helmut E. Weber and published by . This book was released on 1979 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book An Experimental Investigation of Pressure Driven Three dimensional Turbulent Boundary Layers

Download or read book An Experimental Investigation of Pressure Driven Three dimensional Turbulent Boundary Layers written by Stanford University. Thermosciences Division and published by . This book was released on 1987 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Engineering Turbulence Modelling and Experiments 4

Download or read book Engineering Turbulence Modelling and Experiments 4 written by D. Laurence and published by Elsevier. This book was released on 1999-04-14 with total page 975 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings contain the papers presented at the 4th International Symposium on Engineering Turbulence Modelling and Measurements held at Ajaccio, Corsica, France from 24-26 May 1999. It follows three previous conferences on the topic of engineering turbulence modelling and measurements. The purpose of this series of symposia is to provide a forum for presenting and discussing new developments in the area of turbulence modelling and measurements, with particular emphasis on engineering-related problems. Turbulence is still one of the key issues in tackling engineering flow problems. As powerful computers and accurate numerical methods are now available for solving the flow equations, and since engineering applications nearly always involve turbulence effects, the reliability of CFD analysis depends more and more on the performance of the turbulence models. Successful simulation of turbulence requires the understanding of the complex physical phenomena involved and suitable models for describing the turbulent momentum, heat and mass transfer. For the understanding of turbulence phenomena, experiments are indispensable, but they are equally important for providing data for the development and testing of turbulence models and hence for CFD software validation.

Book Overview of Turbulence Models for External Aerodynamics

Download or read book Overview of Turbulence Models for External Aerodynamics written by R. A. W. M. Henkes and published by . This book was released on 1998 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Turbulence Modeling Progress and Future Outlook

Download or read book Turbulence Modeling Progress and Future Outlook written by and published by . This book was released on 1996 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Development of Relaxation Turbulence Models

Download or read book Development of Relaxation Turbulence Models written by C. M. Hung and published by . This book was released on 1977 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book The Structure of High Reynolds Number Turbulent Boundary Layers

Download or read book The Structure of High Reynolds Number Turbulent Boundary Layers written by Alexander J. Smits and published by . This book was released on 1993 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Turbulent atmospheric flow over a backward facing step

Download or read book Turbulent atmospheric flow over a backward facing step written by U K. Kaul and published by . This book was released on 1976 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: