Landfried, Douglas Tyler
(2013)
Characterization of the Behavior of Confined Laminar Round Jets.
Master's Thesis, University of Pittsburgh.
(Unpublished)
Abstract
Laminar jets have been very important in the understanding of fluid dynamics in practical applications. Several examples include expansions in pipes and flow of gas into a large plenum. While much previous research has given consideration to heat transfer behavior and pressure gradients within the confinement, little attention has been paid to quantify the velocity profiles and transitions between various flow regimes. Using a finite volume CFD code, OpenFOAM ®, the incompressible Navier-Stokes equations were solved for a varying expansion ratio and varying Reynolds numbers. In the present analysis, three separate Reynolds numbers are tested (32.2, 48.3, 64.4, based on the inlet jet diameter and velocity), while the expansion ratio is varied from 40-100. Results suggest that initially, the flow characteristics are identical to a free jet. At some downstream location, the presence of the enclosure is felt by the jet and deviations begin to be seen from free jet behavior. This transition region continues until at a sufficiently large downstream location, the flow becomes fully developed, internal Poiseuille flow. In this thesis, analysis is conducted for these transition regions and explanations are offered with practical correlations to successfully predict the important flow physics that occur between free jet behavior and Poiseuille flow. Of primary focus are predictive correlations for the jet centerline velocity and the jet half width, as a function of jet Reynolds number and expansion ratio. Similar functional dependence is also determined for the “linear” decay region of the jet and the reattachment location on the enclosure wall. Key dimensionless parameters are identified, the magnitude of which can be used to classify the flow conditions.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
| Creators | Email | Pitt Username | ORCID  |
|---|
| Landfried, Douglas Tyler | dtl5@pitt.edu | DTL5 | |
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| ETD Committee: |
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| Date: |
24 September 2013 |
| Date Type: |
Publication |
| Defense Date: |
12 July 2013 |
| Approval Date: |
24 September 2013 |
| Submission Date: |
22 July 2013 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
65 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Swanson School of Engineering > Mechanical Engineering |
| Degree: |
MS - Master of Science |
| Thesis Type: |
Master's Thesis |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
confined jets, laminar jets, round jets, turbulent jets, confinement, enclosure, Reynolds number, sudden expansion, computational fluid dynamics, CFD, modelling, OpenFOAM |
| Date Deposited: |
24 Sep 2013 20:10 |
| Last Modified: |
15 Nov 2016 14:14 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/19353 |
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