Showing 4 results for Experimental Test
Hassan Sayyaadi, Masood Rahimian, Mohamad Saed Seif,
Volume 6, Issue 12 (3-2011)
Abstract
In recent years, unmanned vehicles have intensively been developed to reduce risk on human life for marine applications. Predicting the dynamics behavior of an autonomous underwater vehicle is important during the vehicle’s design phase. In other words to design an AUV, one must clarify its maneuverability and controllability based on a mathematical model. The mathematical model contains various hydrodynamics forces and moments expressed collectively in terms of dynamics equations. Therefore, to optimize the AUV design it is necessary to predict maneuvering ability and dynamics behavior of AUV. This can be done by computational simulation.
SUT-2 is an AUV system, being developed by Marine Engineering Research Center, Sharif University of Technology in Iran. Primary dynamics test have been developed in marine engineering laboratory. In this paper dynamics behavior of this AUV is investigated by using experimental test and computational simulation. Results can be used to optimize the dynamics behavior and designing the autonomous controller of AUV.
Seyed Morteza Marashian, Mehdi Adjami, Taghi Aliakbari,
Volume 15, Issue 30 (1-2020)
Abstract
Single point mooring terminals are, as the name implies, facilities of small horizontal dimensions, to which large vessels are moored by means of a bow hawser or by any other means which allows the vessel to rotate 360 around the mooring point. Generally, the single point mooring terminal can have two functions. Primarily, it affords a safe mooring to the vessels. Secondly, it can form a link in the chain for the transport of oil. In this study, with the feasibility of 3D image processing, the SPM translational motion is evaluated. This translational motion includes Surge, Sway, and Heave. In order to ensure the results of the analysis of SPM translational motion, verification is carried out. In the following, by constructing SPM and situating it in reaction condition with regular wave, translational motion is obtained. Finally, the results indicate that image processing is acceptable in translational motion assessment of SPM.
Hodjat Naderi-Asrami, Shabnam Bahrami Asl, Mohamadreza Tabeshpour, Mohammad Saeed Seif,
Volume 16, Issue 32 (11-2020)
Abstract
Experimental measurements of dynamic instabilities in water environments are challenging due to their fluctuation and small amplitude. Most of studies use electrical circuits, this paper aims to use only mechanical methods to measure vortex induced vibrations. Measuring the fluctuations amplitude can help designing mechanisms for movement and for mechanical energy harvesting. This paper uses the novel particle image velocimetry method. The test comprises of a cylinder moving in water with different velocities. Uniform and tapered cylinders are used. Study of tapered cylinder is unprecedented. Output data is in the form of dimensionless amplitude-velocity graphs. From this test velocity for producing largest amplitude is obtained. It is also seen that in the efficient velocity, amplitude of uniform cylinder is larger. While tapered cylinder is suitable for using in currents with variable velocities.
Seyed Morteza Marashian, Mehdi Adjami, Rouhollah Amirabadi,
Volume 18, Issue 35 (5-2022)
Abstract
Armors are a kind of protective layer made of stone or concrete, used in breakwater constructions or coastal lines, arrayed with specific regular or irregular pattern on the breakwater or the coast. Armor damage due to wave attack is the principal failure mode to be considered when designing conventional rubble mound breakwaters. Since the cost of breakwater construction is high, the stability of this structure during its service life is important. This study includes the results of a experimental study stability of rubble mound breakwater covered with armor layers consisting of parsian national armor. In these experiments using irregular wave, the effect of significant wave height, wave period and water level changes on the stability of these concrete armor parts. The results obtained from the damage of the armor layer in the form Nod are presented that the stability of the armor decreases with increasing values of significant wave height and wave period and the armor layer of the rubble mound breakwater will be damaged. The effects of progressive damage on other breakwater components against wave interaction were also evaluated and the results of this study show the efficiency of this New Recommended Concrete Armor.
