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Accession Number:
ADA516486
Title:
Numerical Investigation of Statistical Turbulence Effects on Beam Propagation through 2-D Shear Mixing Layer
Descriptive Note:
Master's thesis
Corporate Author:
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
Report Date:
2010-03-01
Pagination or Media Count:
105.0
Abstract:
A methodology is developed for determining the validity of making a statistical turbulent approach using Kolmogorov theory to an aero-optical turbulent flow. Kolmogorov theory provides a stochastic method that has a greatly simplified and robust method for calculating atmospheric turbulence effects on optical beam propagation, which could simplify similar approaches to chaotic aero-optical flows. A 2-D laminar Navier-Stokes CFD Solver AVUS is run over a splitter plate type geometry to create an aero-optical like shear mixing layer turbulence field. A Matlab algorithm is developed to import the flow data and calculates the structure functions, structure constant, and Fried Parameter ro and compares them to expected Kolmogorov distributions assuming an r23 power law. The range of Cn2s developed from the structure functions are not constant with separation distance, and ranged between 10-12-10-10. There is a consistent range of data overlap within the Cn2s derived from various methods for separation distances within the range 0.01m-0.02m. Within this range ro is found to be approximately 0.05m which is a reasonable value. This particular 2-D shear mixing layer was found to be non-Kolmogorov, but further grid refinement and data sampling may provide a more Kolmogorov-like distribution.
Distribution Statement:
APPROVED FOR PUBLIC RELEASE
