Date of Award

3-2006

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Aeronautics and Astronautics

First Advisor

Ralph A. Anthenien Jr., PhD

Abstract

The research was done as part of an effort to develop alternative fire suppressant technologies for aircraft engine nacelles. The turbulent shear flow behind a surface mounted fence inside an open circuit wind tunnel was investigated experimentally. The tunnel test section was designed to be 2-D and exhibit flow qualities similar to those found in a typical engine nacelle. A 279 mm wide fuel pan was inserted approximately four fence heights downstream of the fence location. The fuel pan was filled using water to simulate fuel with a depth of 32 mm. Cold flow tests were done on different fence configurations with turbulent airflow. The average turbulence intensity in the stream wise direction was 12% at the forward edge of the pan and with no fence in place. The Reynolds number was 2 x 104 in the free stream and based on a fence height of 50.8 mm. Several fences were used to simulate general types of clutter elements. The height, length, degree of perforation, and distance to the fuel pan were all fence geometries that were tested. Measurements were taken of the 2-D flow field along the centerline of the test section using Particle Image Velocimetry (PIV). A separation region with strong reverse flow was found to exist above the pan and have flow characteristics that were largely sensitive to fence dimensions. It was also found that the results for different configurations can be collapsed using the appropriate non-dimensional parameters.

AFIT Designator

AFIT-GAE-ENY06-M04

DTIC Accession Number

ADA449923

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