NOISE OF HIGH PERFORMANCE AIRCRAFTS AT AFTERBURNER
Abstract
Generation of indirect combustion noise inside a military-styled nozzle is a new subject to most members of the aeroacoustics community. The physics of the phenomenon is not sufficiently established. Furthermore, the entropy waves or hot spots that exit the afterburner and enter the nozzle are random and broadband. The problem is, therefore, stochastic in nature. Standard Computational Aero Acoustics and Computational Fluid Dynamics methodology is unable to produce a stochastic wave field in the time domain. Thus, to try to unravel the physics of noise generation inside a military-styled nozzle by numerical simulation would necessarily require the development of a stochastic model inflow boundary condition. The main function of such a boundary condition is to produce an incoming stochastic entropy wave field. Unfortunately, such numerical inflow boundary condition is not available in the literature. The proposed research plan consists of three main elements. They are: 1. Development of a stochastic inflow boundary condition capable of generating a random broadband entropy wave field with user-assigned statistical properties. 2. Development of a computer code for numerical simulation of the passage of random entropy blobs through a military-styled nozzle. 3. Perform a parametric study of the generation of broadband acoustic waves arising from the passage of a field of random entropy blobs through a military-styled nozzle. The primary purpose of the study is to obtain a better understanding of the physics involved. The study uses three dimensional numerical simulation results. The presence of expansion fans and shocks inside the nozzle is expected. Deliverables: Quarterly Progress Reports and Final Report
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512008
Entities
People
- Christopher Tam
Organizations
- Florida State University
- Office of Naval Research
- United States Navy