Date of Award

5-2024

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Mechanical and Civil Engineering

First Advisor

Daniel R. Kirk

Second Advisor

David Fleming

Third Advisor

Paul Schallhorn

Fourth Advisor

Hamidreza Najafi

Abstract

This dissertation presents studies on pressure loss through annular corrugated pipes to determine a friction factor coefficient using nitrogen. Ten different corrugated pipes’ geometries were evaluated via testing and experimentation. The ratio of corrugation height to inner diameter varied from 0.233 to 0.333 and the ratio of corrugation pitch to inner diameter varied from 0.181 to 0.446. Nitrogen flow rates between 0.25 to 94.4 standard liters per minute were used, resulting in Reynolds numbers, based on the corrugated pipe inner diameter, from 100 to 23,000. The experimental set-up was validated using smooth-pipe pressure loss measurements and the derived friction factor showed good agreement with the Moody diagram. Experimental uncertainty analysis was conducted, including the correlated bias error terms, encompassing 95% bounds of the data collected and presented for both derived results Reynolds number and friction factor from the measured inputs. The current results indicate that pipes with smaller pitch to inner diameter ratios transition closer to Re = 1,600. An example of the experimental result includes a corrugated pipe with an inner diameter of 8.64 mm and corrugation pitch of 2.41 mm, at Reynolds number of 300 +/- 7%, the resulting friction factor was 0.183 +/- 32%. Experiments were conducted with two-dimensional bends varying up to 16 in bend radius and 180 degrees. The resulting additional pressure loss due to the bend was within the uncertainty analysis errors and concluded that secondary flow effects are still secondary even for flow through corrugated pipes. CFD was conducted and a comparison of nine different turbulence models were compared with the k-ε (K-epsilon) producing the most accurate results of the differential pressure loss to the experiments conducted within ~10% on average.

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