| Author | Hanif, Md. |
| Call Number | AIT Thesis no. 1063 |
| Subject(s) | Waves--Mathematical models
|
| Note | A thesis submitted in partial fulfilment of the requirements for the Degree of Master of Engineering at the Asian Institute of Technology, Bangkok, Thailand. |
| Publisher | Asian Institute of Technology |
| Abstract | This paper presents the application of Finite Element Method (FEM) to the boundary value problem of wave force analysis on horizontal objects of
elliptic cross-section. The object is considered as a fixed one at the free-surface and at the bottom as well. The fundamental equations and the variationally principle corresponding to them have been introduced, and the
linear matrix equations are derived through the Finite Element discretization.
Linearized boundary conditions have been used based in the assumption that the amplitudes of the generated wave are small compared to the their wave
lengths. In order to optimize the numerical process, the decaying behavior of the local disturbance has been investigated and the results have been used to find an appropriate position for imposing the radiation boundary
condition.
Two dimensional wave field has been considered for the analysis
and in order to observe the behavior of waves on the structure, the wave condition has been varied from shallow to deep water. The FEM Model has
been tested with the known solutions for both the conditions and the convergence criteria obtained with the change of element aspect ratio as well
as with the change of .the number of elements. The monotonic convergence
was achieved when the element length {.6x) was less than or equal to the one tenth of the wave length i.e., x/L // < . 0 .1. Consequent.ly the same criteria was adopted to the new object keeping the same wave conditions. The results of
this improved technique include the determination of force components, moments and inertia coefficients. In addition to this, pressure distribution around
object, scattered wave amplitude, reflection and transmission coefficient and
water profile has also been obtained as a part of the solution. All the results has been presented in the normalized form with dimensionless wave
number. Such a normalized form of results can be easily adopted for the design work of offshore structures of similar geometry. With this powerful model any degree of complicated boundary geometry can be handled in practice. |
| Year | 1978 |
| Type | Thesis |
| School | Student Research Before 1979 |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Thesis (Year <=1979) |
| Chairperson(s) | Suphat Vongvisessomjai ;Gupta, Ashim Das
|
| Examination Committee(s) | Watanabe, Akira ;Arbhabhirama Anat
|
| Scholarship Donor(s) | Government of Canada |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1978 |