Investigation of the Effect of Adaptive Characteristics on Non-Cavitating Noise for Flexible Propeller in Non-Uniform Flow via the Fluid-Structure Interaction Model
Abstract When constructing a low-noise submarine, it is crucial to consider the non-cavitating noise from the propeller. Non-cavitating noise reduction is crucial for submarine stealth and survivability. Recently, several studies have been conducted on the use of flexible propellers as a means of reducing non-cavitating noise. However, there are no studies on the use of […]
A useful guide of effective mesh-size decision in predicting the ultimate strength of flat- and curved plates in compression
Abstract The present study aims to determine the appropriate size of mesh or the number of the element (NoE) for flat- and curved plates, which is suggested to assess its safety subjected to axial compression based on the ultimate limit state (ULS) design and analysis concept. The unstiffened panel (= plate) and stiffened panel, considered […]
Development of Enhanced Empirical-Asymptotic Approach for Added Resistance of Ships in Waves
Abstract This study aims to develop a practical and accurate prediction method for the added resistance of ships in regular wave conditions. To this end, the SNU formula proposed by Yang et al. (2018a) is enhanced for the diffraction-induced added resistance of ships in short waves with arbitrary wave headings. Notably, the SNU formula is […]
Experimental study on hydrodynamic behavior and energy conversion of multiple oscillating-water-column chamber in regular waves
Abstract An oscillating water column (OWC) device is a promising wave energy converter that uses ocean wave energy resources. The OWC chamber absorbs the energy of ocean waves and significantly affects energy conversion performance. In this study, the hydrodynamic performance of a multiple OWC chamber was investigated experimentally, emphasizing its hydrodynamic behavior and energy conversion characteristics. A series of regular wave tests were […]
EXPERIMENTAL STUDY OF A VARIABLE BUOYANCY SYSTEM FOR LOW DEPTH OPERATION
Abstract Autonomous Underwater Vehicles (AUVs) are used for the underwater survey both in coastal areas and deep sea without any human intervention during their operations. However, high energy consumptions required by the thrusters of the AUV’s adversely affect their performance such as range and endurance, etc. Herein, we have presented a novel design and development […]
Experimental study on the towing stability of a towed underwater object
Abstract The towing stability of a towed underwater object was investigated through towing tank model tests. Three types of towing cables were employed, and the attitude of a towed object was measured by an inertial measurement unit. The towed object's geometry and the position of the towing point were fixed. The lower center of gravity […]
An investigation on material diversity of synthetic fiber ropes in the course stability of towing under wind
Abstract The synthetic fiber ropes are commonly employed as the main material for the towing line to connect the towed ship and tug boat. The diversity of material e.g. polyester, aramid, and HMPE could impact the behavior of towing system and lead the instability of towed ship. Following the practical method previously proposed for the towing system analysis, […]
Greenhouse gas reduction and economic cost of technologies using green hydrogen in the steel industry
Abstract Reducing greenhouse gas (GHG) emissions from the steel industry is one of the top priorities for mitigating climate change. Although hydrogen has been considered as a key element to accomplish this task, the effects of various hydrogen-using technologies in steel mills have not been analysed and compared to each other. This paper quantitatively analysed the […]
Optimal duct length of ducted fans for minimizing first blade-passing frequency noise
Abstract Fans generate tone noise and broadband noise. The first blade-passing frequency noise is a tone noise and is the most dominant; attaching a duct and a stator can reduce this noise. However, there has been no theoretical development in using structural characteristics to reduce the noise generated by ducted fans. In this study, noise […]
Application of Machine Learning for Prediction of Wave-Induced Ship Motion
Abstract This paper investigates the possibility of the machine learning technique being applicable in the real-time prediction of wave-induced ship motions. An integrated machine learning model is proposed by considering the two different physical attributes in the equation of motion: memory effects of past motion history and excitation forces induced by incident waves. A long […]
