Project Title:

Boundary Layer Transition Detection System

08.08-4846
Project Title:Boundary Layer Transition Detection System
Company:Innovative Dynamics
Oxnard, CA 93030-6512
Principal Investigator:Dahl, Philip R.

Abstract:

The objective of this project is to develop a prototype Boundary Layer Transition
Detection System (BLTDS) that incorporates piezoelectric material to sense laminar,
transitional, and turbulent boundary layer produced signals and to detect the point
of transition.  A novel concept conceived by the proposer that utilizes solid-state
piezoelectric sensot technology indicates that it is possible to sense both surface
drag shear force and acoustic noise generated by the airflow.  The key elements of
this system utilize polyvinylidene flouride transducer film material (PVDF) for sensing
and a microcomputer for digital signal processing.  Due to its excellent piezoelectric
properties and broadband response, the PVDF can sense the boundary layer surface
vibratory motion responding to frequencies from a few Hz to 100 KHz and higher. 
By incorporating a microcomputer into this system, a number of design advantages
immediately become available.  It will be possible to construct a inintrusive prototype
BLTDS that determines laminar, turbulent, and transitional conditions on both wind
tunnel models as well as actual aircraft flight control surfaces.