Turbulence Modeling for Application to V/STOL Propulsion Induced Effects - Two Dimensional Formulation.
Abstract
Feasibility is established for the use of a statistical vortex model of turbulence to characterize shear flows associated with mixing and entrainment. The model is an extension of an approach used successfully for prediction of inlet flow maximum distortion levels. Analytically it forms the closure required for the governing Reynolds and kinetic energy turbulent flow equations. Applicability of the model to shear flows is validated by focusing on fully developed turbulent flow in a two-dimensional channel. The solutions completely characterize the flow with a single distributive set of vortex (or eddy) properties. This includes the mean velocity profiles, cross correlation (Reynolds) stress terms, root-mean-square levels of the axial and lateral velocity perturbations, and energy production, diffusion, and dissipation terms. Comparisons with an extensive channel data base verify the characterization. In addition, the solutions provide the framework for coupling the analytics with experimental boundary (or initial) conditions to define scaling relations. The studies indicate that a definite variation in turbulence eddy properties exists across the channel. These variations can be determined from measurements of the flow field unsteady pressure fluctuations. The results are applicable to turbulent flow boundary layers and flow mixing problems in general, and ultimately to aircraft propulsion induced effects (e.g., VSTOL) where jet mixing and entrainment dominate the flight/model scaling and simulation requirements. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 15, 1979
- Accession Number
- ADA090331
Entities
People
- Andres H. Ybarra
Organizations
- Vought