(DURIP) A SYSTEM FOR EXPERIMENTAL INVESTIGATION OF UNSTEADY BOUNDARY LAYER TRANSITION AND SEPARATION
Abstract
The request consists of three main components- a dual phase shaker system, infrared (IR) camera and high-performance workstation. The shaker system will enable generation of precise unsteady wind tunnel model motion with variable waveforms, including multifrequency and even random. This will allow investigations of realistic unsteady flow behavior as experienced, for example, by high aspect ratio composite wings during flight. The IR camera will provide nonintrusive measurements of boundary layer transition and separation suitable for airfoils as well as swept and finite wings. IR thermography is ideally suited for unsteady boundary layer transition and separation measurements because it is nonintrusive, can provide the necessary spatial resolution and is more sensitive than for example, pressure sensitive paint. The high-performance workstation will be employed to execute new advanced processing techniques for IR thermography data. It will also drive and control the shaker system. This equipment request is motivated by the recent shift towards high-strength composite materials which allows the use of high-aspect ratio wings with low induced drag that can dramatically increase the range and endurance of flight vehicles. For such wings, unsteady loads resulting from atmospheric turbulence, gusts, or directly from inherent instabilities of the separated flow will elicit strong structural responses. The resulting structural motion can affect boundary layer transition and separation especially when laminar airfoils are employed. The understanding of unsteady boundary layer transition, separation, and the interplay between the two remains a major unresolved issue in aerodynamics. This is due, in part, to difficulties in measuring such phenomena on unsteady platforms. The equipment proposed for acquisition here will permit UArizona researchers to examine unsteadiness that is representative of high aspect ratio wings coupled with detailed measurements of transition and separation. Part of the requested instrumentation (IR camera and workstation) will also support efforts in high-speed aerodynamics research.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 07, 2023
- Source ID
- FA95502110402
Entities
People
- Hermann Fasel
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Arizona