Identifier

etd-0902103-171251

Degree

Master of Science in Mechanical Engineering (MSME)

Department

Mechanical Engineering

Document Type

Thesis

Abstract

Airflow from single and coaxial contoured nozzles with a square cross section is studied using constant temperature anemometry. The inner to outer jet velocity ratio is 1.5. The Reynolds number of the outer jet based on the hydraulic diameter of the outer nozzle exit is 15,300. Results are compared to previous data obtained with circular nozzles under the same conditions. Properties of the jets and their shear layers such as turbulence shear layer thicknesses and growth rates were derived from the velocity record. The mixing between the jets and with the external flow was found to be enhanced by passive forcing. Axis switching was observed in the near field of the jets. Fourier space analysis was conducted. Energies of the preferred modes and their harmonics were computed in the shear layers. A sub-harmonic cascade was observed, evidence of non-linear interaction between the preferred mode and its sub-harmonics.

Date

2003

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

D. E. Nikitopoulos

DOI

10.31390/gradschool_theses.3650

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