Three Dimensional Modeling of Caspian Sea Currents Using FVCOM MODEL

River, Estuarine and Coastal Dynamic

HOW TO INCREASE THE CAPACITY OF AN EXISTING SEA WATER INTAKE

ABSTRACT Sea Water Intakes supplying water for desalination, cooling systems, or other parts of many important industrial components, such as refineries, and power plants are usually built in the shore lines and close to the target systems. In some conditions, such as expansion of the refinery, or other plants and in order to avoid building a new sea water intake because of lack of the suitable land or expending a lot of money, it is required to enhance the amount of withdrawing water and increase the capacity of the existing sea water intake. In such conditions, several important factors such as, minimum required submergence depth for the pumps, maximum allowed current velocity at the entry of the suction chambers, maximum allowed current velocity inside the intake and near the filters, and the flow pattern should be checked

Wake and structure model for simulation of cross-flow/in-line vortex induced vibration of marine risers

Three dimensional responses of riser subjected to Vortex Induced Vibration (VIV) are investigated. Proportionality relations of stress and fatigue damage are mentioned. A computer code has been developed for time domain modeling of VIV of riser accounting for both Cross-Flow (CF) and In-Line (IL) vibration. The wake oscillator model is used to calculate the VIV of each strip. The wake oscillators are coupled to the dynamics of the long riser, while the Newmark-beta method is used for evaluating the structural dynamics of riser. The wake dynamics, including IL and CF vibrations, is represented using a pair of non-linear Van der Pol equations that solved using modified Euler method. The existing experimental and numerical results for stepped and sheared current are used to validate the proposed model and the results show reasonable agreement. The proposed model was implemented on Amir-Kabir semi-submersible riser deployed at the water depth of 713 meters of Caspian Sea. CF/IL VIV of this riser is simulated for various current velocities. The results show that although displacement amplitude of IL direction is lower than CF direction but because of higher curvature, stress values of IL direction for some cases can be higher than CF direction. Also because of higher frequency of IL direction, fatigue damage of this direction can be higher than CF one in some cases. It is shown that with increasing of current velocity; however, variation of displacement amplitude of two directions is low but stress increased and fatigue damage also increased with higher rate. For lower velocities which the modes are controlled with tension, stress and fatigue damage of IL direction is higher than CF direction

Influential factors of loyalty and disloyalty of travellers towards traditional-resorts

With emergence of digital travel platforms, traveler online reviews have become a source of rich information which has a significant role in their perception of the services that influences consumer’s demand for resorts. This study aims to identify and rank influential factors of loyalty and disloyalty of travelers through customer online reviews in traditional resorts using Latent Sentiment Analysis (LSA). Our results indicate factors that creating loyalty and disloyalty toward traditional resorts are different and some of these factors are more significant and different from previous studies in the context of other types of hotels. This study signifies the importance of travellers’ online reviews to the resorts managers and contributes to them to improve loyalty factors and alleviate disloyalty factors

Response based analysis of an FPSO due to arbitrary wave, wind and current loads

EThOS - Electronic Theses Online ServiceGBUnited Kingdo