Measurements of Dissipation Rate and Velocity/Pressure Gradient Correlation for Improvements to Gas Turbine Turbulent Flow Models
Abstract
In this research program, a new comprehensive laser-Doppler velocimeter (CompLDV) experimental technique is being developed and used to measure precisely the instantaneous vector velocity, acceleration, and position of multiple particles within the Kolmogorov scales of high Reynolds number turbulent flows. With at least 4 particles at a given instant this results in the fine-spatial-resolution instantaneous measurement of the complete rate-of-strain and vorticity tensors and the dissipative and velocity fluctuation-pressure gradient fluctuation correlation terms in the Reynolds-averaged equations for complex three-dimensional turbulent flows, without employing any assumptions. Currently there is no other such experimental technique available and the information is important for improved turbulence modeling of complex 3-d flows like those in gas turbines and separated and vortical flows. Since this technique measures the instantaneous acceleration of the flow, the relationships between the instantaneous fluid acceleration and the velocity structure also are being examined in some detail for the first time. During this grant, this technique was used to obtain data for: (1) three-dimensional turbulent boundary layers and vortical and separated flows similar to those in gas turbines (7000 < Re theta <23,000), with and without high free-stream turbulence levels and (2) rough-wall boundary layers, which are also of interest to gas turbines.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 31, 2006
- Accession Number
- ADA451080
Entities
People
- Edgar Orsi
- K. T. Lowe
- Roger L. Simpson
Organizations
- Virginia Tech