Computational Assessment of Flow through a High-Flow Nacelle Bypass for Low Supersonic Boom

Jain, Nishan

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https://hdl.handle.net/2142/26111 Copy

Description

Title

Computational Assessment of Flow through a High-Flow Nacelle Bypass for Low Supersonic Boom

Author(s)

Jain, Nishan

Issue Date

2011-08-25T22:14:34Z

Director of Research (if dissertation) or Advisor (if thesis)

Bodony, Daniel J.

Department of Study

Aerospace Engineering

Discipline

Aerospace Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Reynolds-averaged Navier-Stokes (RANS)
• turbulence modeling
• sonic boom minimization
• high-flow nacelle bypass
• gearbox
• fairing
• blockage
• turbulence shock interaction

Abstract

Sonic boom minimization is a challenge faced by the aviation community to enable high- speed civilian aircraft flying supersonically over populated land. One of the concepts proposed to reduce sonic boom incorporates a high-flow secondary nacelle bypass to enclose the engine and its protrusions where the flow is diverted around a gearbox through a set of inlet and exit guide vanes. To assess the flow quality within the bypass, computational studies are conducted using traditional RANS-based methods. Three levels of geometric complexity are considered—including the full engine, only the aft vane sections, and only one channel from the aft section—to evaluate global and local flow characteristics and to evaluate the influence of different turbulence models on the flow solutions. The aft vane calculations were conducted in “clean” and “vaned” configurations which correspond to experimental models whose data were used for validation purposes. Comparisons between the full engine and detailed single channel calculations show a weak dependence on the turbulence model used for the mean flow predictions as well as strong turbulence-shock interactions. The clean and vaned aft bypass sections exhibit reasonable agreement with the experimental data but show a stronger influence of the turbulence model on predictive accuracy due to a laminar-turbulent transition affecting the inflow velocity profile.

Graduation Semester

2011-08

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http://hdl.handle.net/2142/26111

Copyright and License Information

Copyright 2011 by Nishan Jain

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