Download or read book Comparison of Turbulence Models for Nozzle Afterbody Flows with Propulsive Jets written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical investigation was conducted to assess the accuracy of two turbulence models when computing non-axisymmetric nozzle-afterbody flows with propulsive jets. Navier-Stokes solutions were obtained for a Convergent-divergent non-axisymmetric nozzle-afterbody and its associated jet exhaust plume at free-stream Mach numbers of 0.600 and 0.938 at an angle of attack of 0 deg. The Reynolds number based on model length was approximately 20 x 10(exp 6). Turbulent dissipation was modeled by the algebraic Baldwin-Lomax turbulence model with the Degani-Schiff modification and by the standard Jones-Launder kappa-epsilon turbulence model. At flow conditions without strong shocks and with little or no separation, both turbulence models predicted the pressures on the surfaces of the nozzle very well. When strong shocks and massive separation existed, both turbulence models were unable to predict the flow accurately. Mixing of the jet exhaust plume and the external flow was underpredicted. The differences in drag coefficients for the two turbulence models illustrate that substantial development is still required for computing very complex flows before nozzle performance can be predicted accurately for all external flow conditions. Compton, William B., III Langley Research Center CONVERGENT-DIVERGENT NOZZLES; NAVIER-STOKES EQUATION; NOZZLE FLOW; TURBULENCE MODELS; K-EPSILON TURBULENCE MODEL; JET EXHAUST; FREE FLOW; EXHAUST GASES; COMPUTATIONAL FLUID DYNAMICS; AXISYMMETRIC FLOW; ANGLE OF ATTACK; AERODYNAMIC COEFFICIENTS; PLUMES; REYNOLDS NUMBER; TURBULENCE; MACH NUMBER; DISSIPATION; AFTERBODIES; AERODYNAMIC DRAG...
Download or read book Comparison of Turbulence Models for Nozzle Afterbody Flows with Propulsive Jets written by William B. Compton (III.) and published by . This book was released on 1996 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comparison of Turbulence Models for Nozzle afterbody Flows with Propulsive Jets written by William B. Compton and published by . This book was released on 1996 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Paper written by and published by . This book was released on 1995 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1990 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Method of Difference Potentials and Its Applications written by Viktor S. Ryaben'kii and published by Springer Science & Business Media. This book was released on 2001-11-06 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first English edition of a well-known Russian monograph. This book presents the method of difference potentials first proposed by the author in 1969, and contains illustrative examples and new algorithms for solving applied problems of gas dynamics, diffraction, scattering theory, and active noise screening.
Download or read book Comparison of Turbulence Models for Simulating Flow in Waterjets written by Xian Luo and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have developed a fast numerical algorithm for simulating flows in complex moving domains. The new hybid smoothed profile/spectral element method exhibits high-order accuracy as well as great computational efficiency as it removes the tyranny of mesh generation. Here we extend this work by incorporating a variational multiscale large eddy formulation for modeling the subgrid turbulent scales. We present verification and validation studies of the combined method and compare different turbulence mdoeling methodologies. Subsequently, we apply it to study laminar, transitional and turbulent flows in an axial-flow waterjet propulsion system (ONF AxWJ-1). The robustness and efficiency of our methods enable parametric studies of many cases, which may aid greatly in the early stages of design and evaluation of such propulsion systems.
Download or read book Turbulence Measurements of Separate Flow Nozzles with Mixing Enhancement Features written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-19 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comparison of turbulence data taken in three separate flow nozzles, two with mixing enhancement features on their core nozzle, shows how the mixing enhancement features modify turbulence to reduce jet noise. The three nozzles measured were the baseline axisymmetric nozzle 3BB, the alternating chevron nozzle, 3A12B, with 6-fold symmetry, and the flipper tab nozzle 3T24B also with 6-fold symmetry. The data presented show the differences in turbulence characteristics produced by the geometric differences in the nozzles, with emphasis on those characteristics of interest in jet noise. Among the significant findings: the enhanced mixing devices reduce turbulence in the jet mixing region while increasing it in the fan/core shear layer, the ratios of turbulence components are significantly altered by the mixing devices, and the integral lengthscales do not conform to any turbulence model yet proposed. These findings should provide guidance for modeling the statistical properties of turbulence to improve jet noise prediction. Bridges, James and Wernet, Mark P. Glenn Research Center NASA/TM-2002-211592, E-13376, NAS 1.15:211592, AIAA Paper 2002-2484
Download or read book Turbulence Model Comparisons for a High Speed Aircraft written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-21 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Four turbulence models are described and evaluated for transonic flows over the High-Speed Research/industry baseline configuration known as Reference H by using the thin-layer, upwind, Navier-Stokes solver known as CFL3D. The turbulence models studied are the equilibrium model of Baldwin-Lomax (B-L) with the Degani-Schiff (D-S) modifications, the one-equation Baldwin-Barth (B-B) model, the one-equation Spalart-Allmaras (S-A) model, and Menter's two-equation Shear Stress Transport (SST) model. The flow conditions, which correspond to tests performed in the National Transonic Facility (NTF) at Langley Research Center, are a Mach number of 0.90 and a Reynolds number of 30 x 10 (exp. 6) based on mean aerodynamic chord for angles of attack of 1 deg., 5 deg., and 10 deg. The effects of grid topology and the representation of the actual wind tunnel model geometry are also investigated. Computed forces and surface pressures compare reasonably well with the experimental data for all four turbulence models.Rivers, Melissa B. and Wahls, Richard A.Langley Research CenterCOMPUTATIONAL FLUID DYNAMICS; COMPUTATIONAL GRIDS; NAVIER-STOKES EQUATION; TURBULENCE MODELS; TRANSONIC WIND TUNNELS; SUPERSONIC AIRCRAFT; APPLICATIONS PROGRAMS (COMPUTERS); WIND TUNNEL TESTS; BALDWIN-LOMAX TURBULENCE MODEL; ANGLE OF ATTACK; GRID GENERATION (MATHEMATICS); MATHEMATICAL MODELS; TOPOLOGY; SHEAR STRESS
Download or read book First NASA Industry High Speed Research Configuration Aerodynamics Workshop written by Richard M. Wood and published by . This book was released on 1999 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Some Turbulence Models to the Computation of an Axisymmetric Jet in Streaming Flow written by S. Biringen and published by . This book was released on 1974 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiple scale Turbulence Modeling of Boundary Layer Flows for Scramjet Applications written by G. Fabris and published by . This book was released on 1981 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Survey of Turbulence Models for the Computation of Turbulent Jet Flow and Noise written by and published by . This book was released on 1999 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Air Breathing Engines and Aerospace Propulsion written by B. N. Raghunandan and published by Allied Publishers. This book was released on 2004 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contributed papers presented at the 7th National Conference on Air Breathing Engines and Aerospace Propulsion, hosted at I.I.T., Kanpur.
Download or read book Future Space Transport System Components under High Thermal and Mechanical Loads written by Nikolaus A. Adams and published by Springer Nature. This book was released on 2020-10-26 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book presents the findings of Collaborative Research Center Transregio 40 (TRR40), initiated in July 2008 and funded by the German Research Foundation (DFG). Gathering innovative design concepts for thrust chambers and nozzles, as well as cutting-edge methods of aft-body flow control and propulsion-component cooling, it brings together fundamental research undertaken at universities, testing carried out at the German Aerospace Center (DLR) and industrial developments from the ArianeGroup. With a particular focus on heat transfer analyses and novel cooling concepts for thermally highly loaded structures, the book highlights the aft-body flow of the space transportation system and its interaction with the nozzle flow, which are especially critical during the early phase of atmospheric ascent. Moreover, it describes virtual demonstrators for combustion chambers and nozzles, and discusses their industrial applicability. As such, it is a timely resource for researchers, graduate students and practitioners.
Download or read book The Effect of Exhaust Plume afterbody Interaction on Installed Scramjet Performance written by Thomas Alan Edwards and published by . This book was released on 1988 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
