The Impact of Damper Properties on the Amplitude and Frequency of Bluff Body Behaviors Under Vortex-Induced Vibration for Maritime Engines

School Name

Spring Valley High School

Grade Level

10th Grade

Presentation Topic

Engineering

Presentation Type

Non-Mentored

Oral Presentation Award

1st Place

Written Paper Award

1st Place

Abstract

Vortex Induced Vibrations (VIV) are a phenomenon where the fluid flow causes oscillations against an object called a bluff body by vortex shedding. This phenomenon has recently been studied as a source of renewable energy. The purpose of this study was to test the feasibility of a direct VIV powered maritime propulsion system. It was hypothesized that testing conditions would allow for operation of the proposed mechanical propulsion system and that the combination of the largest bluff body with the lowest damping would achieve the highest amplitude in its vibration. A structure was created to support the bluff body and damper. The bluff bodies consisted of four designs and were suspended by eight types of dampers. The combinations were then exposed to fluid flow at eight different velocities. Results were analyzed by investigating the relationship of velocity against amplitude and frequency. Regressions were also done for statistical analysis. The 2.75 cm bluff body with the 4.35 cm damper achieved the highest amplitude at 1.6 m/s. However, the regressions determined that the data was not statistically significant, and the independent variables did not correlate with the dependent variables (p>�), although these tests did not account for the lock-in region of VIV. In addition, results show that all combinations did not achieve the ability to make a direct drive engine feasible. However, the results demonstrate that it is possible to create a VIV power generator for the propulsion system.

Location

Founders Hall 222 B

Start Date

3-30-2019 1:45 PM

Presentation Format

Oral and Written

Group Project

No

COinS
 
Mar 30th, 1:45 PM

The Impact of Damper Properties on the Amplitude and Frequency of Bluff Body Behaviors Under Vortex-Induced Vibration for Maritime Engines

Founders Hall 222 B

Vortex Induced Vibrations (VIV) are a phenomenon where the fluid flow causes oscillations against an object called a bluff body by vortex shedding. This phenomenon has recently been studied as a source of renewable energy. The purpose of this study was to test the feasibility of a direct VIV powered maritime propulsion system. It was hypothesized that testing conditions would allow for operation of the proposed mechanical propulsion system and that the combination of the largest bluff body with the lowest damping would achieve the highest amplitude in its vibration. A structure was created to support the bluff body and damper. The bluff bodies consisted of four designs and were suspended by eight types of dampers. The combinations were then exposed to fluid flow at eight different velocities. Results were analyzed by investigating the relationship of velocity against amplitude and frequency. Regressions were also done for statistical analysis. The 2.75 cm bluff body with the 4.35 cm damper achieved the highest amplitude at 1.6 m/s. However, the regressions determined that the data was not statistically significant, and the independent variables did not correlate with the dependent variables (p>�), although these tests did not account for the lock-in region of VIV. In addition, results show that all combinations did not achieve the ability to make a direct drive engine feasible. However, the results demonstrate that it is possible to create a VIV power generator for the propulsion system.