Loading...

Aero-Hydro-Elastic Analysis of a Floating Beam in a Water Channel Subjected to Cross Wind

Tavanbakhsh, Sadeq | 2020

406 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 53117 (45)
  4. University: Sharif University of Technology
  5. Department: Aerospace Engineering
  6. Advisor(s): Dehghani Firouzabadi, Rouhollah
  7. Abstract:
  8. In static floating structures such as floating bridges and offshore runways that are in contact with the water surface from the floor and with the open air from the top, three types of interactions occur: the interaction of the structure with air, the interaction of the structure with water and Interaction of air with water. Due to the long length of such structures and approaching their natural frequencies to the standing wave frequencies (seiche frequencies), the analysis of the elastic behavior of the structure alone is not enough, but the structure-air-water interaction must be evaluated simultaneously in a system. Leading research addresses this issue and examines the behavior of an aero-hydroelastic system.In this study, assuming a high length-to-width ratio of the floating structure, the structure is modeled with an Euler-Bernoulli beam. Providing an analytical solution to a problem in which the structural-air-water interaction is investigated simultaneously is very complex. If the irregular geometric shape of the riverbed or canal and structural cross-sectional changes are also involved, it makes it almost impossible to provide an analytical solution. As a result, in the present study, a combination of potential flow, boundary element and finite element methods has been used to solve the problem. Finally, by presenting a boundary element-finite element model for the system, the aero-hydroelastic behavior at different cross wind flow velocities has been evaluated.The results show that in the aero-hydrodynamic system, the system frequencies are very close to the frequencies of the hydrodynamic system. In this system, with increasing wind speed, the effect of crosswind on the system dominates and the natural frequencies of the system converge to a constant value. Also, in this case, the damping is a small amount that indicates that the Oscillations continue for a long time. The results of the aero-hydroelastic system indicate that the presence of the structure as an elastic boundary between the two fluid fields, changes the process of changing and the amount of natural frequencies. As the crosswind velocity increases, the system frequencies initially increase but then decrease and converge to a constant value. The analysis of the results indicates that at low speeds the behavior of the system is affected by the behavior of the structure. as the momentum of the flow increases, the behavior of the aero-hydroelastic system is affected by the crosswind
  9. Keywords:
  10. Aeroelasticity ; Hydroelasticity ; Boundary Element Method ; Finite Element Method ; Standing Waves ; Floating Structure

 Digital Object List

 Bookmark

No TOC