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Results for “nozzle flow”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Commercial turbofan engine exhaust nozzle flow analyses using PAB3D

Recent developments of a three-dimensional (PAB3D) code have paved the way for a computational investigation of complex aircraft aerodynamic components. The PAB3D code was developed for solving the simplified Reynolds Averaged Navier-Stokes equations in a three-dimensional multiblock/multizone structured mesh domain. The present analysis was applied to commercial turbofan exhaust flow systems. Solution sensitivity to grid density is presented. Laminar flow solutions were developed for all grids and two-equation k-epsilon solutions were developed for selected grids. Static pressure distributions, mass flow and thrust quantities were calculated for on-design engine operating conditions. Good agreement between predicted surface static pressures and experimental data was observed at different locations. Mass flow was predicted within 0.2 percent of experimental data. Thrust forces were typically within 0.4 percent of experimental data.

Abdol-Hamid, Khaled S.↗
NASA NTRS1992

DSMC analysis of species separation in rarefied nozzle flows

The direct-simulation Monte Carlo method has been used to investigate the behavior of a small amount of a harmful species in the plume and the backflow region of nuclear thermal propulsion rockets. Species separation due to pressure diffusion and nonequilibrium effects due to rapid expansion into a surrounding low-density environment are the most important factors in this type of flow. It is shown that a relatively large amount of the lighter species is scattered into the backflow region and the heavier species becomes negligible in this region due to the extreme separation between species. It is also shown that the type of molecular interaction between the species can have a substantial effect on separation of the species.

Chung, Chan-Hong↗
NASA NTRS2001

Effect of Mixing Enhancement Devices on Turbulence in Separate Flow Nozzles

This paper presents the effects of several mixing enhancement devices on turbulence in jet nozzles. The topics include: 1) The Advanced Subsonic Technology (AST) Program; 2) Test Programs SFNT97 and SFNT2K; 3) Facility; 4) Mixing Enhancement Nozzles; 5) IR reductions; 6) Schlieren of Chevrons; and 7) Aeroacoustics of Enhanced Mixing-Paradigm. This paper is presented in viewgraph form.

Bridges, James↗
NASA NTRS2014

USM3D Predictions of Supersonic Nozzle Flow

This study focused on the NASA Tetrahedral Unstructured Software System CFD code (USM3D) capability to predict supersonic plume flow. Previous studies, published in 2004 and 2009, investigated USM3D's results versus historical experimental data. This current study continued that comparison however focusing on the use of the volume souring to capture the shear layers and internal shock structure of the plume. This study was conducted using two benchmark axisymmetric supersonic jet experimental data sets. The study showed that with the use of volume sourcing, USM3D was able to capture and model a jet plume's shear layer and internal shock structure.

Carter, Melissa B.↗
NASA NTRS2015

Computational and Experimental Study of Supersonic Nozzle Flow and Shock Interactions

This study focused on the capability of NASA Tetrahedral Unstructured Software System's CFD code USM3D capability to predict the interaction between a shock and supersonic plume flow. Previous studies, published in 2004, 2009 and 2013, investigated USM3D's supersonic plume flow results versus historical experimental data. This current study builds on that research by utilizing the best practices from the early papers for properly capturing the plume flow and then adding a wedge acting as a shock generator. This computational study is in conjunction with experimental tests conducted at the Glenn Research Center 1'x1' Supersonic Wind Tunnel. The comparison of the computational and experimental data shows good agreement for location and strength of the shocks although there are vertical shifts between the data sets that may be do to the measurement technique.

Carter, Melissa B.↗