Date of Award:

5-2008

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Mechanical and Aerospace Engineering

Committee Chair(s)

Barton Smith

Committee

Barton Smith

Committee

Byard Wood

Committee

Heng Ban

Abstract

Separating oscillating and pulsating flows in an internal adverse pressure gradient geometry are studied experimentally. Simultaneous velocity-pressure measurements demonstrate that the minor losses associated with oscillating flow in an adverse pressure gradient geometry can be smaller or larger than for steady flow. Separation is found to begin high in the diffuser and propagate downward. Flows are able to remain attached further into the diffuser with larger Reynolds numbers, larger stroke lengths, and smaller diffuser angles. The extent of separation grows with L0/h. The minor losses grow with increasing displacement amplitude in the range 10 < L0/h < 40. Losses decrease with Re𝛿 in the range of 380 < Re < 740. It is found that the losses increase with increasing diffuser angle for 12° < θ < 30° . The losses for pulsating flow are found to be greater than for those of oscillating flow for small steady flow ratios and decrease to the oscillating flow value or below as the steady flow ratio approaches one. The nondimensional acoustic power dissipation increases with Reynolds number in the range of 380 < Re < 740 and decreases with stroke length in the range of 10 < L0/h < 40. The nondimensional resistance is independent of Reynolds number, decreases with increasing stroke length, and decreases with increasing diffuser angle. The inertance decreases slightly with increasing stroke length and appears to be Reynolds number independent.

Checksum

5fdae3948bc58bd75c94cb2f21226329

Download

Share

COinS

Copyright for this work is retained by the student. If you have any questions regarding the inclusion of this work in the Digital Commons, please email us at .