• 한국군사과학기술학회지
• /
• 제17권1호
• /
• pp.33-40
• /
• 2014

Due to its unmanned feature and some of being matured underwater technologies, UUV(Unmanned Undersea Vehicle) is increasingly considered as a utility player in today's battle-field. The operational benefit of submarine-based UUV operation could be enormous yet the integration challenges are significant, particularly for most of small conventionally-powered submarines. In this paper, we consider UUV operational methodology via the conventional submarine's torpedo tube. Two previous attempts having been done to retrieve the UUV through torpedo tube are reviewed, and their pros and cons are also analyzed. Then, an alternative option is proposed for UUV operation via torpedo tube. In addition, some of practical challenges are also discussed in the paper.

• 한국해양공학회지
• /
• 제23권2호
• /
• pp.53-57
• /
• 2009

Unmanned surface vehicles (USVs) conduct various missions while exchanging information with control centers. Maritime security, coastal surveillance, and sea surface and undersea inspections are included in the important missions of USVs. To carry out these missions, large amounts of information are required from sensors, such as cameras, radars, and sonars. High bandwidth wireless communication is necessary to send this information to the control center in real time. In general, USVs are made using small boats. The motions of small boats are easily influenced by sea waves and the magnitude of changes in the attitude is large and the period of the changes is short in comparison with large ships. Thus, the direction of an antenna beam pattern for a wireless communication system in a USV can change rapidly, and with a large magnitude. In addition, since the reflection of electromagnetic waves on the sea surface is not negligible, the effect of multipath noises on the wireless communication system must be considered carefully. There are also several other elements that negatively affect wireless communication systems in USVs. This paper presents the wireless communication environment to be considered in the design and implementation of wide bandwidth communication systems for USVs. Short test results for wireless communication on the sea are also given.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제12권1호
• /
• pp.892-901
• /
• 2020

We used a numerical method to estimate the hydrodynamic maneuvering derivatives for the heave-pitch coupling motion of an underwater glider. It is very important to assess the hydrodynamic maneuvering characteristics of a specific hull form of an underwater glider in the initial design stages. Although model tests are the best way to obtain the derivatives, numerical methods such as the Reynolds-averaged Navier-Stokes (RANS) method are used to save time and cost. The RANS method is widely used to estimate the maneuvering performance of surface-piercing marine vehicles, such as tankers and container ships. However, it is rarely applied to evaluate the maneuvering performance of underwater vehicles such as gliders. This paper presents numerical studies for typical experiments such as static drift and Planar Motion Mechanism (PMM) to estimate the hydrodynamic maneuvering derivatives for a Ray-type Underwater Glider (RUG). A validation study was first performed on a manta-type Unmanned Undersea Vehicle (UUV), and the Computational Fluid Dynamics (CFD) results were compared with a model test that was conducted at the Circular Water Channel (CWC) in Korea Maritime and Ocean University. Two different RANS solvers were used (Star-CCM+ and OpenFOAM), and the results were compared. The RUG's derivatives with both static drift and dynamic PMM (pure heave and pure pitch) are presented.