Diffusion of a linear-source passive contaminant by a turbulent flow - Effect of an imposed uniform deformation
Abstract
The thermal wake of a heated wire in a 9-m/sec turbulent flow subjected to uniform compression or expansion by the section geometry is investigated experimentally, considering the heat of the wire as a passive contaminant. One working section has an inlet 15 cm high and 60 cm wide tapering smoothly over its 1-m length to an outlet 60 cm high and 15 cm wide; the other has inlet and outlet 15 cm high and 60 cm wide tapering to 30 by 30 cm at the midpoint of its 1-m length. Mean and fluctuating temperature and velocity fields and temperature-signal probability-density functions are determined, and the results are presented graphically. It is shown that turbulent diffusion is potentiated by compression and suppressed by expansion. A theoretical model of thermal-wake structure is proposed. The design of the test apparatus is treated in detail in an appendix.
- Publication:
-
Journal de Mecanique Theorique et Appliquee
- Pub Date:
- 1983
- Bibcode:
- 1983JMecT...2.1013P
- Keywords:
-
- Flow Distortion;
- Thermal Diffusion;
- Turbulent Diffusion;
- Diffusivity;
- Flow Velocity;
- Probability Density Functions;
- Temperature Profiles;
- Wakes;
- Wind Tunnel Tests;
- Fluid Mechanics and Heat Transfer