Adjoint-based Aeroacoustic Control
Abstract
A technique for controlling complex unsteady high-speed flows is being developed. Our approach uses numerical solutions of the adjoint of the compressible flow equations to circumvent the complexity of the flow and directly determine the sensitivity of a specified control objective to changes in actuation. Since this method requires a complete physical description of a turbulent flow which is only currently available from direct numerical simulations, the immediate objective obviously is not to develop a practical control scheme. Instead, the method's utility is in its ability to study flow control in applications like jet noise reduction where a practical prediction capability is lacking. It provides working controls which can be generalized and at the same time provides unique full-fidelity simulation databases of a noisy and its corresponding quieted flow, which can be compared to study the subtle mechanisms of sound generation. The key result of the previous funding period was the development of the adjoint-based formulation in two-dimensions and its (remarkably) successful demonstration on a two-dimensional mixing layer. That was the first time a non-trial-and-error methodology successfully reduced noise from a free shear flow to The summary of our accomplishments of this funding period.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2006
- Accession Number
- ADA450363
Entities
People
- Jonathan B. Freund
- Mingjun Wei
- Randall R. Kleinman
Organizations
- University of Illinois Urbana–Champaign