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Full-Text Articles in Mechanical Engineering
Damping And Fluidelastic Instability In Two-Phase Cross-Flow Heat Exchanger Tube Arrays, Joaquin Moran
Damping And Fluidelastic Instability In Two-Phase Cross-Flow Heat Exchanger Tube Arrays, Joaquin Moran
Publications and Scholarship
An experimental study was conducted to investigate damping and fluidelastic instability in tube arrays subjected to two-phase cross-flow. The purpose of this research was to improve our understanding of these phenomena and how they are affected by void fraction and flow regime. The model tube bundle had 10 cantilevered tubes in a parallel-triangular configuration, with a pitch ratio of 1.49. The two-phase flow loop used in this research utilized Refrigerant 11 as the working fluid, which better models steam-water than air-water mixtures in terms of vapour-liquid mass ratio as well as permitting phase changes due to pressure fluctuations. The void …
Surface Friction Guiding For Reduced High-Frequency Lateral Vibration Of Moving Media, V. Kartik, Jonathan A. Wickert
Surface Friction Guiding For Reduced High-Frequency Lateral Vibration Of Moving Media, V. Kartik, Jonathan A. Wickert
Jonathan A. Wickert
The free and forced vibration of a moving medium is examined in an application where distributed friction guiding is used to control lateral position passively. Subambient pressure features formed in the guides intentionally modify the naturally occurring self-pressurized air bearing and increase the contact force between the medium and the guide's surface. These features increase friction to a level beyond that achievable based on the nominal wrap pressure. The moving medium is modeled as a beam that is transported over frictional regions and subjected to prescribed boundary disturbances arising from runout of a supply or take-up roll. For axial transport …
On Damping And Fluidelastic Instability In A Tube Bundle Subjected To Two-Phase Cross-Flow, Joaquin Moran, David S. Weaver
On Damping And Fluidelastic Instability In A Tube Bundle Subjected To Two-Phase Cross-Flow, Joaquin Moran, David S. Weaver
Publications and Scholarship
An experimental study was conducted to investigate damping and uidelastic instability in tube arrays subjected to twophase cross-ow. The purpose of this research was to improve our understanding of these phenomena and how they are affected by void fraction and ow regime. The working uid used was Freon 11, which better models steam-water than air-water mixtures in terms of vapour-liquid mass ratio as well as permitting phase changes due to pressure uctuations. The damping measurements were obtained by plucking the monitored tube from outside the test section using electromagnets. An exponential function was tted to the tube decay trace, producing …