This study involved the shape of water jet nozzle to promote blasting ability and an increase of projection distance when cleaning VLBC cargo hold. Furthermore, I researched the effect of pressure, length of reducer, nozzle caliber size and nozzle shape on the nozzle through CFD simulation. Simulation of water jet projection process inside VLBC cargo hold was done in both 2D and 3D environment. Simulation results show installing suitable nozzle can increase the cleaning effect of cargo hold.

As the fabrication technology used in FPDs(flat-panel displays) advances, the size of these panels is increasing and the pattern size is decreasing to the um range. Accordingly, a cleaning process during the FPD fabrication process is becoming more important to prevent yield reductions. The purpose of this study is to develop a FPD cleaning system and a cleaning process using a two-phase flow. The FPD cleaning system consists of two parts, one being a cleaning part which includes a two-phase flow nozzle, and the other being a drying part which includes an air-knife and a halogen lamp. To evaluate the particle removal efficiency by means of two-phase flow cleaning, silica particles 1.5μm in size were contaminated onto a six-inch silicon wafer and a four-inch glass wafer. We conducted cleaning processes under various conditions, i.e., DI water and nitrogen gas at different pressures, using a two-phase-flow nozzle with a gap distance between the nozzle and the substrate. The drying efficiency was also tested using the air-knife with a change in the gap distance between the air-knife and the substrate to remove the DI water which remained on the substrate after the two-phase-flow cleaning process. We obtained high efficiency in terms of particle removal as well as good drying efficiency through the optimized conditions of the two-phase-flow cleaning and air-knife processes.

In recent years, there was many conflagration about special structure such as wooden cultural assets, warehouses and factories. The common causes of increase in the fire damage were difficulty of the initial suppression and absence of equipment for appropriate disaster prevention. In this study, the destruction-spray nozzles, a core technology of destruction-spray fire vehicle which is possible for fire suppression of special structure was studied using the finite element method. As a result, the maximum deviation of the part nozzle was 18.1% compared with the reference value. Second, the maximum deviation of the nozzle module was 13.5% compared with the part nozzle. Third, the safety factor about internal pressure of the nozzle module was suitable as 13.6. Finally, the performance of the designed destruction-spray nozzle was satisfied with 4,652.1L/min in excess of the target performance.

In this paper, a commercial multibody dynamics program ADAMS was utilized to investigate the model for the multi-joint boom conflicts. In this process, CATIA, ANSYS and ADAMS were used to develop the simulation. The addition of ADAMS made the system more accurate and improved precision of the system. In brief, the 3D CAD model of the structure was initially developed via CATIA. After this, the CATIA models were exported to ANSYS for creating flexible-body modeling by using formatted file. Subsequently, with ADAMS, the flexible body model was directly imported from ANSYS which performed the analyses of the dynamic collision of the nozzle boom conflicts. This contained the information regarding geometry and model shapes of the flexible body. Using ADAMS/Durability, it was possible to determine the strain energy for the nozzle configuration by crashing the contact structure that was created. Via this procedure, the acquired simulation analysis of nozzle showed interestingly good results with respect to the objectives of the study

In this study, by using nickel chloride solution as a raw material, a nano-sized nickel oxide powder with an average particle size below 50 nm was produced by spray pyrolysis reaction. A spray pyrolysis system was specially designed and built for this study. The influence of nozzle tip size on the properties of the produced powder was examined. When the nozzle tip size was 1 mm, the particle size distribution was more uniform than when other nozzle tip sizes were used and the average particle size of the powder was about 15 nm. When the nozzle tip size increases to 2 mm, the average particle size increases to roughly 20 nm, and the particle size distribution becomes more uneven. When the tip size increases to 3 mm, particles with an average size of 25 nm and equal to or less than 10 nm coexist and the particle size distribution becomes much more uneven. When the tip size increases to 5 mm, large particles with average size of 50 nm partially exist, mostly consisting of minute particles with average sizes in the range of 15~25 nm. When the tip size increases from 1 mm to 2 mm, the XRD peak intensities greatly increase while the specific surface area decreases. When the tip size increases to 3 mm, the XRD peak intensities decrease while the specific surface area increases. When the tip size increases to 5 mm, the XRD peak intensities increase again while the specific surface area decreases.

In this study, using a tin chloride solution as the raw material, a nano-sized tin oxide powder with an average particle size below 50 nm is generated by a spray pyrolysis process. The properties of the tin oxide powder according to the nozzle tip size are examined. Along with an increase in the nozzle tip size from 1 mm to 5 mm, the generated particles that appear in the shape of droplets maintain an average particle size of 30 nm. When the nozzle tip size increases from 1 mm to 2 mm, the average size of the generated particles is around 80-100 nm, and the ratio of the independent particles with a compact surface structure increases significantly. When the nozzle tip size is at 3 mm, the majority of the generated particles maintain the droplet shape, the average size of the droplet-shaped particles increases remarkably compared to the cases of other nozzle tip sizes, and the particle size distribution also becomes extremely irregular. When the nozzle tip size is at 5 mm, the ratio of droplet-shaped particles decreases significantly and most of the generated particles are independent ones with incompact surface structures. Along with an increase in the nozzle tip size from 1 mm to 3 mm, the XRD peak intensity increases, whereas the specific surface area decreases greatly. When the nozzle tip size increases up to 5 mm, the XRD peak intensity decreases significantly, while the specific surface area increases remarkably.

여름철 고온기 온실 내 효율적 증발냉방을 위하여 다량 포그 분무가 가능하고 설치비용이 저렴하도록 한 터보팬 2류체 노즐로 포그 분무장치를 구성하고 소형 유리온실에 2.2 m 높이로 설치하여 냉방시험을 실시하였다. 이 장치의 분무시험 결과 평균분무입경이 29 ㎛이고 1대당 포그 분무량은 160 ㎖/min로 비산반경 2 m이내에서 입자들이 모두 증발하는 것으로 나타났다. 이 장치를 평면적 228 ㎡인 단동 유리온실에 2대를 설치하여 냉방실험한 결과, 외기의 온도 30.2℃, 상대습도 81.2%인 때 온실 내 공기의 온도 28.8℃, 상대습도 87.5%의 낮은 냉각효과를 나타내었다. 문헌 조사와 냉방실험 결과로부터 여름철 우리나라 남부지역의 외기온 35℃를 기준으로 단동온실은 50% 차광에서 증발냉각에 의해 온실 내 공기온도를 외기온보다 2∼3℃ 낮추려면 환기회수 1회/분, 물분무량은 10 ㎖/min/㎡인 것으로 추정되었다.

노즐시험기로 측정되는 직물의 당김 힘은 직물이 갖는 포괄적인 촉감을 나타낸다. 노즐시험기는 기존 KES 시스템보다 저가이며, 측정에 있어서 절차가 간단하고 빠르다. 본 연구에서는 노즐시험기로 측정되는 직물의 촉감을 정량적으로 평가하기 위해 마찰법칙을 기초로 하여 반 실험적 촉감 방정식을 개발하였다. 모델 식에서 고려된 변수들은 직물의 마찰계수, 그리고 직물의 굽힘 길이와 전단 신도에 의해 결정되는 직물의 3차원적 변형 특성을 나타내는 드레이프 계수이다. 12 종류의 서로 다른 물성의 면과 폴리에스터 직물들을 사용하여 실험 측정한 촉감 값과 모델 방정식으로부터 예측한 촉감 값들을 비교 분석하였다. 높은 마찰계수, 높은 굽힘 길이, 그리고 낮은 전단 신도를 갖는 직물일수록 높은 촉감 마찰력, 즉 낮은 촉감 성능을 보여주었다. 실험 측정한 촉감 값과 모델 식으로부터 계산한 값들 사이 잘 일치하였으며, 이와 같은 결과는 모델 식을 사용하여 직물의 고유 물성들로써 촉감의 객관적인 예측이 가능함과 더불어 촉감 성능의 향상을 위한 직물설계에 있어서도 유용한 정보를 제공할 수 있음을 보여준다.

Fishing efficiency of a trawl vessel can be enhanced by increasing the swept area per unit time, which can be attained either by increasing the mouth size of the net, or by increasing the towing speed. To improve fishing and fuel efficiency of trawl vessels targeting fishes of greater mobility, in which the towing speed is more critical in determining fishing efficiency, we conducted a series of model tests to evaluate the performance of the newly-designed nozzle propeller before installing it in a trawl vessel to verify its towing speed and fuel efficiency in the sea. By conducting further model tests in the experimental basin, we redesigned the propeller of stern trawler to improve the resistance and propulsion performance. Through actual fishing operations, we evaluated the improvement in fuel and fishing efficiency by installing the new nozzle propeller. The trawling speed increased by 0.6kts at the same engine power (RPM), while the engine margin increased by more than 20%. The increased towing speed by installing the redesigned propeller is expected to enhance fishing performance through increasing the number of hauling- and casting operations per unit times, while shortening the towing duration. Analysis of the Catch-Per-Unit-Effort (CPUE) data indicated that the mean CPUE of trawl fishery increased from 3.04kg/m in year 2007 to 6.15kg/m in year 2008, confirming enhanced fishing efficiency by adopting the redesigned propeller.

In this study, the researcher investigated the effects of water mist nozzle shape on water mist according nozzle shape angle(=30°, 45°, 60°, 75° and 90°). It was found that the water mist spray with nozzle When exit angle of water mist nozzle is =90° as result examining about spray special quality of water mist, velocity distribution was expose to maximum. And temperature distribution of target plate was looked tendency that range low. Water mist spray system that consider in this research is one of the most important utilities providing water mist in order to supply fire extinguishing.

In order to provide the mechanism of nozzle clogging, recovered nozzles for high strength steel grade were examined carefully after continuous casting. The thickness of clogged material in SEN is increased in the following order: from the bottom to the top of the nozzle, upper part of slag line, and the pouring hole. Nozzle clogging material begins to form due the adhesion of metal to nozzle wall, the decarburization, and reduction of oxide in the refractory by Al and Ti in the melt. The reduction of oxide in the refractory by Al and Ti improves the wettability of the melt on the refractory and forms a thin Al-Ti-O layer. Metal containing micro alumina inclusions is solidified on the Al-Ti-O layer, and the solid layer grows due to the heat evolution through the nozzle wall. Thermodynamic calculation has been made for the related reactions. The effect of superheat to the nozzle clogging is discussed on ultra low carbon steel and low carbon steel.

Trawlers have to a sufficient towing force due to it's characteristics of the high performance. The newly constructed trawler with the conventional propellers shows the sufficient towing force, so that the propeller and engine are optimized. In the 1970s, many trawlers were imported from overseas by Korean fisheries industries. But the engine output degradation with year by year caused the trawlers to decrease the towing speed of the vessels. On the previous studies, the nozzle propeller had not so good efficiency with increasing of resistance in high-speed cruising operation over 15knots. But the trawling operation is just required the higher thrust and towing force, so that the nozzle propeller is very profitable for the it's effectiveness. A new nozzle propeller was designed for the 4,462G/T trawler, Dong-San, operated by Dongwon Industries Co., Ltd. to improve the towing speed, and the model tests were performed. The model ship and model propeller are preciously manufactured and used model tests in basin. The resistance test and propeller open water test were performed for the cases of the half and full loads. The required engine horse power and RPM were evaluated analytically by the speed-power curve, when the trawler was equipped with the nozzle propeller. The results of tests showed that the towing speed 4.85knots on the design load waterline requires the 200 engine RPM and 2,567ps in the delivered horsepower.

가스터빈에서 연료 분무 노즐은 연소 특성에 영향을 미치는 중요한 부품이다. 스월 분무 장치를 설계하기 위하여 유량과 분무액적 평균 직경을 설계변수로 정하고 연료 분무 노즐의 최적화를 수행하였다. 설계변수는 이중 노즐의 실험값들을 비교하여 중요한 영향을 미치는 변수로 선정하였다. 민감도는 유량과 분무액적 평균 직경의 변화에 따른 값을 사용하였다. 이중 오리피스형 스월 분무장치의 형상 최적설계를 통하여 유량의 미립화를 높이도록 연구하였다. 최적설계를 위하여 실험 계획법을 이용하였으며, 영향을 적게 미치는 설계변수들은 설계대상에서 제외하였다. 분무 노즐의 분무액적 평균 직경을 사용한 결과는 Jasuja의 액적 평균 이론을 이용하여 도출된 결과와 유사함을 알 수 있었다. 연구 결과는 이중 오리피스형스월 분무장치와 이와 비슷한 종류의 노즐 최적화를 위한 특성을 파악하고 최적의 유량과 허용 공차를 제시하였다.

Nozzle geometry influences gas dynamics making sprayed particle behavior one of the most important parameters in cold spray process. Gas flows at the entrance convergent section of the nozzle takes place at relatively high temperature and are subsonic. Thus, this region is a very suitable environment for heating spray particle. In this study, numerical simulation and experiments were conducted to investigate the effect of nozzle contour, entrance geometry of nozzle and powder injection position at nozzle on the cold spray process. The process changes were observed through numerical simulation studies and the results were used to find a correlation with coating properties.

Water jet trajectories and velocity deficits from a high pressurize nozzles were experimentally observed. In this article, several parameters affecting plugging and erosion onto the steam generator tube were quantitatively analyzed. Visualization, velocity distribution, and spray growth rate with different nozzle configurations have been mainly focused using a 2-D PDPA (Phase Doppler Particle Analyzer) system. The results indicated that trajectories along the centerline regardless of their momentum has its potential core region. However, the phenomena from the peripheral part need to be meticulosly considered. Accordingly, it is evident that quantitative velocity deficits at the outer region are outstanding due to the aerodynamical drag and entrainment.

본 논문에서는 펌프 노즐이 부착된 잠수 선형의 유동에 관해 수치해석 결과를 보여준다. 이는 속도분포, 양력계수, 영각의 값을 갖는 펌프젯 노즐이 선체와 부착되었을 때와 부착되지 않았을 때의 종강도 모멘트 등의 값들을 계산한다. 선형의 속도 분포에 따른 노즐의 영향면적과 양력계수(변호의 특성요인) 종강도 모멘트, 영각에 따른 도함수 등을 보여준다.

The contamination problem is getting worse now a day because of the industrial activities. Recently it has been announced that there's environmental hormone in river and lake which produces clean water, also there's too many of algae reproduces under the water and some virus in the drinking water. The quality of water is very important. pure and clean water is not only a precondition for human being to live but a basic factor to improve the quality of life. so a water purification system must be developed. This study is about the surface washing treatment technique. We tried to use a rotary nozzle to get a tush degree of efficiency, for it was not enough with present way of washing. The nozzle is run by water pressure. The results of the experiment are as follows. We got a clean and equal surface after washing. After washing, the water's maximum consistency was 330NTU and it shows that this way is better than before one with 215NTU. Clean level of the filter was 6˚and it's 2.8 times higher than 17˚with the old way. We can see the results that the new way of washing is more effective than old way based on this study.