Phased Array Beamforming for Aeroacoustics

In This Section

Synopsis:

This course will present physical, mathematical, and some practical aspects of acoustic testing with the present generation of arrays and processing methods. The students will understand the capabilities and limitations of the technique, along with practical details. They will learn to design and calibrate arrays and run beamforming software, including several algorithms and flow corrections. Advanced techniques in frequency-domain and time-domain beamforming will be presented. The important topics of electronics hardware and software for data acquisition and storage are outside the scope of the course, apart from a general discussion of requirements.

Key Topics:

  • Gain an understanding of diagnostic techniques for measuring noise-source characteristics and how they may be applied to your projects
  • Find out how advances in array technology can extend the capabilities of your existing facilities
  • Learn how to apply these techniques for testing in a wide range of situations
  • Become familiar with beamforming software

Who Should Attend:

Jet-noise and airframe systems researchers, automotive manufacturers, aircraft engine manufacturers, and professionals in other areas of industry where suppression of noise is important. Engineers and scientists working in aeroacoustics, aerodynamic measurement technology, aircraft design, array sensor systems, and air breathing propulsion will find this course extremely useful.

Course Information:

Type of Course: Instructor-Led Short Course
Course Level: Intermediate


Course scheduling available in the following formats:


  • Course at Conference
  • On-site Course
  • Stand-alone/Public Course

Course Length: 2 days
AIAA CEU's available: yes

Outline

Course Outline:


I. Overview
A. Objectives of phased array tests
1. Source location
2. Acoustic measurements in nonacoustic settings
3. Source component separation
4. Far field synthesis from near field data
B. Sample applications
C. Airframe noise measurements with wind tunnel models
D. Beamforming theory
E. Analysis and presentation of results

II. Testing and Analysis with Classical Beamforming
A. Wide band sparse array design
B. Test setup
1. Free jet wind tunnels: three-dimensional ray tracing for convection correction
2. Closed, hardwall wind tunnels
3. Static engine tests
C. Conceptual overview of data acquisition
D. Coordinates and grid generation
E. Array calibration
F. Data format
G. Beamforming
H. Visualization of results

III. Advanced Techniques for Special Situations
A. Cancellation of interference by subspace projection
B. Suppression of sidelobes
C. Superresolution and adaptive beamforming
D. Matched field processing recombination of partially coherent fields
E. Moving sources

Course Outline

Overview


  • Objectives of phased array tests
    • Source location
    • Acoustic measurements in nonacoustic settings
    • Source component separation
    • Far field synthesis from near field data
    • Source component separation
  • Sample applications
  • Airframenoise measurements with wind tunnel models
  • Beamforming theory
  • Analysis and presentation of results

Testing and Analysis with Classical Beamforming


  • Wideband sparse array design
  • Test setup
    • Free jet wind tunnels: three-dimensional ray tracing for convection correction
    • Closed, hardwall wind tunnels
    • Static engine tests
  • Conceptual overview of data acquisition
  • Coordinatesand grid generation
  • Array calibration
  • Data format
  • Beamforming
  • Visualization of results

Advanced Techniques for Special Situations


  • Cancellation of interference by subspace projection
  • Suppression of side lobes
  • Super resolution and adaptive beamforming
  • Matched field processing recombination of partially coherent fields
  • Moving sources
Materials

Course Materials

Since course notes will not be distributed onsite, AIAA and your course instructor are highly recommending that you bring your computer with the course notes already downloaded to the course. Once you have registered for the course, these course notes are available about two weeks prior to the course event, and are available to you in perpetuity.


Instructors

Course Instructor:


Dr. Robert P. Dougherty’s company, OptiNav, Inc., develops phased array beamforming systems for aeroacoustics and does research for the Navy and NASA. Previously, he was Associate Technical Fellow at Boeing, where he developed the RDIFF and CDUCT nacelle acoustic propagation codes. He is an Affiliate Associate Professor at the University of Washington.