Accession Number:
ADA281683
Title:
Numerical Simulation of Two-Dimensional Spatially-Developing Mixing Layers
Descriptive Note:
Contractor rept.
Corporate Author:
INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA
Personal Author(s):
Report Date:
1994-05-01
Pagination or Media Count:
45.0
Abstract:
Two-dimensional, incompressible, spatially developing mixing layer simulations are performed at Re 10 2 and 10 4 with two classes of perturbations applied at the inlet boundary 1 combinations of discrete modes from linear stability theory, and 2 a broad spectrum of modes derived from experimentally measured velocity spectra. The effect of the type and strength of inlet perturbations on vortex dynamics and time-averaged properties are explored. Two-point spatial velocity and autocorrelations are used to estimate the size and lifetime of the resulting coherent structures and to explore possible feedback effects. The computed time-averaged properties such as mean velocity profiles, turbulent statistics, and spread rates show good agreement with experimentally measured values. It is shown that by forcing with a broad spectrum of modes derived from an experimental energy spectrum many experimentally observed phenomena can be reproduced by a 2-D simulation. The strength of the forcing merely affected the length required for the dominant coherent structures to become fully-developed. Thus intensities comparable to those of the background turbulence in many wind tunnel experiments produced the same results, given sufficient simulation length. Mixing layers, Numerical simulation, Spatial simulation.
Descriptors:
- *MATHEMATICAL MODELS
- *MIXING
- *TWO DIMENSIONAL FLOW
- *SHEAR FLOW
- VELOCITY
- SIMULATION
- STABILITY
- DYNAMICS
- LAYERS
- TWO DIMENSIONAL
- THEORY
- ENERGY
- WIND
- STATISTICS
- INTENSITY
- RATES
- TURBULENCE
- ESTIMATES
- TIME
- BOUNDARIES
- SPECTRA
- PROFILES
- LENGTH
- FEEDBACK
- WIND TUNNEL TESTS
- BACKGROUND
- PERTURBATIONS
- AGREEMENTS
- MEAN
- FREE STREAM
- INLETS
- WIND TUNNELS
- INCOMPRESSIBLE FLOW
Subject Categories:
- Operations Research
- Fluid Mechanics