The measurement of 2 turbulent fluid flows with temperature fluctuation using Laser-Doppler technique
Abstract
The measurement of turbulence in two flow fields with temperature fluctuation was examined: the natural convection flow between two horizontal boundaries and the exhaust flow from a jet engine combustor. Laser Doppler velocimeters with dual Bragg cells were developed for the measurements. A phase lock demodulator was used with on-line computer to obtain time domain data for the natural convection flow. A high speed digital counter was employed to acquire velocity and turbulent intensity data for the combustor flow. Convection experiments were carried out in a deep horizontal layer of water heated from below and cooled from above with well insulated side wall. The range of Rayleigh number ws from 10E9 to 10E12. Heat flux measurements correlated well with previous experimental data even with small width to height aspect ratios from 0.3 to 1. Power spectra of both the vertical and horizontal velocities showed that the turbulence is random even at the smallest aspect ratio measured.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1982
- Bibcode:
- 1982PhDT........22L
- Keywords:
-
- Fluid Flow;
- Jet Engines;
- Jet Exhaust;
- Laser Doppler Velocimeters;
- On-Line Systems;
- Temperature Gradients;
- Turbulent Flow;
- Boundary Layer Combustion;
- Bragg Cells;
- Computer Techniques;
- Convective Heat Transfer;
- Flow Velocity;
- Phase Lock Demodulators;
- Power Spectra;
- Fluid Mechanics and Heat Transfer