Comparison of Turbulence Models for Nozzle-Afterbody Flows with Propulsive Jets

Comparison of Turbulence Models for Nozzle-Afterbody Flows with Propulsive Jets
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 122
Release: 2018-07-17
Genre:
ISBN: 9781722971144

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...

Method of Difference Potentials and Its Applications

Method of Difference Potentials and Its Applications
Author: Viktor S. Ryaben'kii
Publisher: Springer Science & Business Media
Total Pages: 568
Release: 2001-11-06
Genre: Mathematics
ISBN: 9783540426332

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.

Computation of Axisymmetric Separated Nozzle-afterbody Flow

Computation of Axisymmetric Separated Nozzle-afterbody Flow
Author: James L. Jacocks
Publisher:
Total Pages: 36
Release: 1980
Genre: Airplanes
ISBN:

The development of a computer program for solving the compressible, axisymmetric, mass-averaged Navier-Stokes equations is described. The basic numerical algorithm is the MacCormack explicit predictor-corrector scheme. Turbulence modeling is accomplished using an algebraic, two-layer eddy viscosity model with a novel modification dependent on the streamwise gradient of vorticity. Comparisons of computed results with experimental data are presented for several nozzle-afterbody configurations with either or simulated plumes. (Author).

Air Breathing Engines and Aerospace Propulsion

Air Breathing Engines and Aerospace Propulsion
Author: B. N. Raghunandan
Publisher: Allied Publishers
Total Pages: 752
Release: 2004
Genre: Technology & Engineering
ISBN: 9788177646900

Contributed papers presented at the 7th National Conference on Air Breathing Engines and Aerospace Propulsion, hosted at I.I.T., Kanpur.