Date of Award

3-10-2010

Document Type

Thesis

Degree Name

Master of Science in Applied Physics

Department

Department of Engineering Physics

First Advisor

Steven T. Fiorino, PhD.

Abstract

A methodology is developed for determining the validity of making a statistical turbulent approach using Kolmogorov theory to an aero-optical turbulent ow. 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 r2/3 power law. The range of C2n's 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 C2n's 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.

AFIT Designator

AFIT-GAP-ENP-10-M03

DTIC Accession Number

ADA516486

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