Unsteady motion and transition to turbulence in developing curved duct flow
Abstract
An experiment was performed to further the understanding of developing flows in curved ducts of square cross-section. Unlike most earlier works, attention was paid to investigating the time-dependent character of the motion. Mean and unsteady flow characteristics were determined using flow visualization and a laser-Doppler velocimeter. Only one velocity component, that aligned in the longitudinal (streamwise) coordinate direction, was measured. Notwithstanding, the time histories, autocorrelations and spectra derived reveal a time-periodic motion that becomes turbulent with increasing Reynolds number. The results are of intrinsic fundamental value and also illustrate the danger of imposing symmetry of the conservation equations on numerical solutions of this flow.
- Publication:
-
6th Symposium on Turbulent Shear Flows
- Pub Date:
- 1987
- Bibcode:
- 1987stsf.proc...13A
- Keywords:
-
- Ducted Flow;
- Flow Geometry;
- Flow Visualization;
- Laser Doppler Velocimeters;
- Transition Flow;
- Unsteady Flow;
- Data Reduction;
- Fast Fourier Transformations;
- Flow Stability;
- Reynolds Number;
- Velocity Measurement;
- Fluid Mechanics and Heat Transfer