Turbulence development in non-uniform supersonic jets for supersonic jet noise reduction
Abstract
Turbulence development in non-uniform supersonic jets for supersonic jet noise reduction The proposed program leverages uniquely capable experimental techniques to define the characteristics of heated supersonic turbulent plumes developing from prescribed non-uniform nozzle exit conditions. The noise produced by high speed, high temperature exhausts of tactical aircraft engines causes crewperson hearing damage and special operational concerns for community noise for the Navy. Physics-based approaches are needed to reduce jet noise and to transition technologies from the lab scale to the full scale. In developing these approaches, a rich physical description of the complicated turbulent, variable property flow physics involved is needed. Currently, neither the statistical behavior of supersonic shear layer turbulence nor the characteristics of its stochastic behavior is sufficiently defined for a number of pressing needs such as computational validation, noise prediction inputs, and reduced-order modeling for noise control. Further, other researchers have noted that noise radiated by actual, installed engines differs from anything seen in the laboratory. The proposed work addresses these gaps in information by systematic study of supersonic plumes using a 250 kHz repetition rate velocimeter developed during the ONR Hot Jet Noise Basic Research Challenge. By modifying the Virginia Tech Hot Supersonic Jet Rig for cross-sectional variations in plume total pressure, total temperature and core turbulence, physical aspects related to actual engine geometries will be examined systematically. The goals for outcomes of the program include 1. Producing new information for interpreting full-scale plume turbulence and noise results obtained in other work. 2. Systematically studying and explaining the impact of plume core variations on plume turbulence development relevant to jet noise radiation. 3. Providing new test cases, including well-characterized inflow, for validation of computational models being developed by the Navy.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 23, 2016
- Source ID
- N000141612444
Entities
People
- Kevin Lowe
Organizations
- Office of Naval Research
- United States Navy
- Virginia Tech