• Journal of Mechanical Science and Technology
• /
• v.18 no.12
• /
• pp.2265-2272
• /
• 2004

The aquaculture tank is used for breeding fish in sea water which was pumped up to land. The flow characteristics in the aquaculture were investigated with varying the tank geometry and flow rate. The numerical analysis has been employed for calculating the velocity and temperature distributions in a water tank of rectangular type. The finite volume method and SIMPLE algorithm with 3-dimensional standard $\kappa$-$\varepsilon$ turbulence model were used for the numerical analysis. For comparison with experimental results, the PIV system was applied to visualize the flow patterns quantitatively. The numerical results showed good agreements with the experimental results. The mean velocity and temperature versus aquarium depth were represented for various circulating flow rates. Especially, the aquaculture environment is recommended that the aquarium depth has to be d=0.5 m, and this case is the condition of higher velocity and temperature in winter season.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.14 no.2
• /
• pp.198-204
• /
• 2011

This paper presents the experimental result to investigate the characteristics of turbulent wake generated by submarine. A SUBOFF nude model which was assumed as an axial -symmetric body was used to create wake, and a thin strut was mounted on the top of the model. The experiments were conducted in a circulating water channel(CWC), and a hot-film was used to measure the turbulence in wake cross-section at the distance range of 0.0~2.0L from the model. The hot film anemometer measured turbulent velocity fluctuations, and the timeaveraged mean velocity and turbulent intensity are obtained from the acquired time-series data. Measured results show well the general characteristics of turbulent intensity, kinetic energy and mean velocity distribution. Also, experimental equations are derived. These experimental equations show well the general characteristics of the turbulent wake behind the submerged body with simple configuration.

• Journal of international Conference on Electrical Machines and Systems
• /
• v.3 no.1
• /
• pp.48-53
• /
• 2014

In December 2011 and July 2012, two sets of 840MVA hydro-generator of Three Gorges on Yangtze River with Close-loop-self-circulating evaporative cooling (CLSCEC) system were put into commercial operation. In this paper, we make engineering summary of these two generators with CLSCEC system. We also make a comparison between the internal water cooling (IWC) hydro-generator and the CLSCEC hydro-generator used in Three Gorges power plant in fields of their operating characteristics, working performances, technical features, working safety and reliability. In addition, engineering structures, type tests' results and systematic emulating calculation of CLSCEC schemes are analyzed.

• Journal of Ocean Engineering and Technology
• /
• v.14 no.4
• /
• pp.9-16
• /
• 2000

This paper deals with the numerical and experimental study on the characteristics of the flow around a sunken vessel. Numerical simulation of the two dimensional steady flow on the midship section are carried out by the CFD code which is developed by using finite volume method and which includes the standard $textsc{k}$-$\varepsilon$ model with standard wall function. A experimental study is also carried out for the 1/100 scale model in circulating water channel. A velocity fields around the ship are measuremed by using particle image velocimetry technique. And the fluid forces acting on the ship hull by uniform current are measured by two axis load cell. The computed and measured velocity fields on the midship section are compared with each other in the view point of velocity dstribution and reattachement length, which shows good agreement in quality. The drag force on the vessel also showed the same tendency in both computational and experimental results. However, the quantitative disagreements are shown due to the three dimensional effect of the experiment. The result are used to determine the functional efficiency and stability of the vessel as a artificial reef.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.14 no.3
• /
• pp.364-371
• /
• 2011

This paper presents experimental results and derived experimental equations to investigate the turbulent wake characteristics generated by the self-propelled SUBOFF submarine model. A self-propelled SUBOFF model which was assumed as an axial-symmetric body was used to create wake, and a thin strut was mounted on the topside of the model. The experiments were conducted in a circulating water channel(CWC), and the hot-film was used to measure the turbulence in wake cross-section at the distance range of 0.0~2.0L from the model. The hot film anemometer measured turbulent velocity fluctuations, and the time-averaged mean velocity and turbulent intensity are obtained from the acquired time-series data. Measured results show well the general characteristics of turbulent intensity, kinetic energy and mean velocity distribution. Also, this paper presents derived experimental equations, which is extended result to the reference [1]. These experimental equations show well the general characteristics of the turbulent wake behind the self-propelled submerged body.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.16 no.3
• /
• pp.8-16
• /
• 2020

This paper presents the heating performance analysis results of a ground-source heat pump (GSHP) system using hybrid ground heat exchanger (HGHE). In this paper, the HGHE refers to the ground heat exchanger (GHE) using both a surface water heat exchanger (SWHE) and a vertical GHE. In order to evaluate the system performance, we installed monitoring sensors for measuring temperatures and power consumption, and then measured operation data with 4 different load burdened ratios of the HGHE. During the entire measurement period, the average heating capacity of the heat pump was 37.3 kW. In addition, the compressor of the heat pump consumed 9.4 kW of power, while the circulating pump of the HGHE used 6.7 kW of power. Therefore, the average heating coefficient of performance (COP) for the heat pump unit was 4.0, while the system including the circulating pump was 2.7. Finally, the parallel use of SWHE and VGHE was beneficial to the system performance; however, further researches are needed to optimize the design data for various load ratios of the HGHE.

• Journal of Ocean Engineering and Technology
• /
• v.27 no.6
• /
• pp.1-6
• /
• 2013

A 25ft class fishing leisure boat is developed, and the resistance performances are investigated by a model test in a high-speed circulating water channel. The design speed of the developed ship is 25 knots using a 150 ps outboard engine. A catamanan type hull form using a planing section is adopted considering the Froude number and large deck area. The effect of a center body attached on the bottom of the cross deck is studied under various conditions. Wave patterns are observed to make clear the relationship between the resistance performance and the wave characteristics. The results show that the shape of the center body and the position of the chine line can have a strong effect on the resistance performance in a certain velocity range.

• Journal of the Society of Naval Architects of Korea
• /
• v.42 no.2 s.140
• /
• pp.80-87
• /
• 2005

A set of experiments was carried out for obtaining the velocity field around the hydrofoil of finite span, using a wing of the NACA 0012 section in a circulating water channel. DPIV technique was used to measure the velocity field, and the velocity measurements along the span were done for 3 speeds, 3 submerged depths, and 4 angles of attack. Experimental data are compared with the theoretical assumptions, as well as the numerical findings by Lee and Lee(2004). Special care is given to the flow near the tips and in the region close to the leading edge. Though indirect, using the measured data of the velocity, it is now possible to compare the aerodynamic and the hydrodynamic strength of the circulation distribution of a wing in the framework of the lifting-line theory.

• Environmental Analysis Health and Toxicology
• /
• v.3 no.1_2
• /
• pp.55-64
• /
• 1988

Experiments were performed on mice to investigate the influences of ampicillin and ethanol on the immune response. Ampicillin was injected intraperitoneally and ethanol was administered in the drinking water. Mice were sensitized and challenged with sheep red blood cells. Immune responses were evaluated by humoral immunity, cellular immunity, peripheral circulating white blood cell and phagocyte activity. 1. The combined administration of ampicillin and ethanol as compared to ampicillin had not influence on the weight of spleen, but increased the weight of thymus. 2. Humoral immune response was slightly reduced by ampicillin. Especially, the combined administration of ampicillin and ethanol significantly reduced hemclysin production. 3. Cellural immune response was reduced by ampicillin. The combine administration of ampicillin and ethanol significantly reduced cellural immune response. 4. Peripheral circulating white blood cell was reduced by the combined administration of ampicillin and ethanol as compared to ampicillin. 5. The combined administration of ampicillin and ethanol as compared to ampicillin had not influence on the phagocyte activity.

• Environmental Analysis Health and Toxicology
• /
• v.4 no.1_2
• /
• pp.1-10
• /
• 1989

Experiments were performed on mice to investigate the influences of doxycycine and ethanol on the immune responses. Doxycycline was injected intraperitoneally and ethanol was administered in the drinking water. Mice were sensitized and challenged with sheep red blood cells. Immune responses were evaluated by humoral immunity, cellular immunity, peripheral circulating white blood cell and phagocyte activity. Pathotoxicological influences were measured by serum protein and albumin. The weight of spleen, thymus and liver were measured. Doxycline and ethanol combined administration decreased the weight of thymus and spleen. Humoral and cellular immune response were reduced by doxycycline administration. Especially ethanol combined administration significantly reduced humoral and cellular immune response. Phagocyte activity was increased by ethanol combined administration and peripheral circulating white blood cell was significantly increased by ethanol adminstration. Ethanol combined administration decreased serum A/G ratio.