• 한국유체기계학회 논문집
• /
• 제2권3호
• /
• pp.37-44
• /
• 1999

In a screw-type centrifugal pump, the pump head deteriorates from single-phase flow to the choke due to an increased air entrainment at a wide tip clearance compared to that of a narrow tip clearance. Moreover, at a narrow tip clearance, the pump head became partially higher in a two-phase flow than that of a single-phase flow near the best efficiency point in low void fraction region. Therefore, we observed the internal flow pattern by using a stroboscope and we measured the mean size of bubbles from the images obtained with a high speed camera. Then, we investigated the influences of the mean size of bubbles, tip clearances and flow patterns on pump performance.

• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
• /
• pp.57-62
• /
• 2004

In the current study the effects on pump performances of a conventional centrifugal pump for Newtonian and non-Newtonian fluid were experimentally studied. The study aimed to compare the pump characteristics for Newtonian and non-Newtonian fluid. The working fluids are water, aqueous sugar solution, glycerin solution, muddy solution and pulp solution. The pump characteristics with high viscosity fluids were different. The operating efficiency for the sugar and glycerin solutions were decreased to $8.1\%$ and $12.9\%$ than that of water. The head reductions of the muddy solution for different concentration ratios were decreased to $7.97\%,\;15.11\%$ and $24.87\%$ than that of water And the head reductions of the pulp solution for different concentration ratios were decreased to $11.87\%,\;19.79\%$ md $36.81\%$ than that of water.

• 재활간호학회지
• /
• 제4권2호
• /
• pp.251-264
• /
• 2001

The purpose of study was to compare body image between diabetes mellitus patients who used insulin pump therapy and didn't use insulin pump therapy. The study design was comparative survey study the subjects were 60 diabetes mellitus patients who used insulin pump therapy and 60 diabetes mellitus patients who didn't use insulin pump therapy at B hospital in Busan. The data were collected from 15th April to 20th August, 1998. The instrument used for this study were Osgood's body image scale. The collected data were analyzed frequency, percentage, $X^2$-test, mean, standard deviation, t-test, ANOVA, Scheffe test. The results were as follows 1. Demographical characteristics between diabetes mellitus patients who used insulin pump therapy and didn't use insulin pump therapy were no significant difference. 2. Characteristics related disease between diabetes mellitus patients who used insulin pump therapy and didn't use insulin pump therapy were significant difference in paticipation of D.M. meeting, no of paticipation of D.M. meeting. 3. Body inmage score of diabetes mellitus patients was $69.08{\pm}18.13$. In body image, diabetes mellitus patients who used insulin pump therapy were higher than that didn't use insulin pump therapy(t=1.964, P<.05) 4. In body image's each item, common-strange item, noble-humble item, competent-incompetent item, light-heavy item, diabetes mellitus patients who used insulin pump therapy were higher than diabetes mellitus patients who didn't use insulin pump therapy(P<.05). 5. In body image according to economic status, marital status, occupational status were significantly difference. 6. In body image according to causes of regular hospital visiting, paticipation of diabetes mellitus class were significantly difference. In conclusion, diabetes mellitus patients who used insulin pump therapy were more positive than diabetes mellitus patients who didn't use insulin pump therapy.

• 재활간호학회지
• /
• 제4권1호
• /
• pp.105-118
• /
• 2001

The purpose of study was to compare body image between diabetes mellitus patients who used insulin pump therapy and didn't use insulin pump therapy. The study design was comparative survey study the subjects were 60 diabetes mellitus patients who used insulin pump therapy and 60 diabetes mellitus patients who didn't use insulin pump therapy at B hospital in Busan The data were collected from 15th April to 20th August, 1998. The instrument used for this study were Osgood's body image scale. The collected data were analyzed frequency, percentage, $X^2$-test, mean, standard deviation, t-test, ANOVA, Scheffe test. The results were as follows 1. Demographical characteristics between diabetes mellitus patients who used insulin pump therapy and didn't use insulin pump therapy were no significant difference. 2. Characteristics related disease between diabetes mellitus patients who used insulin pump therapy and didn't use insulin pump therapy were significant difference in paticipation of D.M. meeting, no of paticipation of D.M. meeting. 3. Body inmage score of diabetes mellitus patients was $69.08{\pm}18.13$. In body image, diabetes mellitus patients who used insulin pump therapy were higher than that didn't use insulin pump therapy(t=1.964, P<.05) 4. In body image's each item, common-strange item, noble-humble item, competent-incompetent item, light-heavy item, diabetes mellitus patients who used insulin pump therapy were higher than diabetes mellitus patients who didn't use insulin pump therapy(P<.05) 5. In body image according to economic status, marital status, occupational status were significantly difference. 6. In body image according to causes of regular hospital visiting, paticipation of diabetes mellitus class were significantly difference. In conclusion, diabetes mellitus patients who used insulin pump therapy were more positive than diabetes mellitus patients who didn't use insulin pump therapy.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2002년도 춘계학술대회논문집
• /
• pp.235-239
• /
• 2002

In this study, a AGV(Auto Guide Vehicle) is presented and the dynamic characteristics of AGV driving device is investigated. The design factors of hydraulic pump and motor is an important component for it's performance characteristics. the dynamic characteristics of hydraulic pump and motor is simulated by using commercial code AMESim. Simulation results show that each behavior can be predicted with changing the various parameters.

• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 2004년도 학술대회지
• /
• pp.99-107
• /
• 2004

Lubrication characteristics between a cylinder block and a valve plate for high speed bent-axis type hydraulic pump play an important role in volumetric efficiency and durability of pump. In this paper, a finite element method is presented for the computation of the pressure distribution between a cylinder block and a valve plate for high speed bent-axis type hydraulic pump. Also, a Runge-Kutta method is applied to simulate the cylinder block dynamics of three-degrees of freedom motion. From the results of computation, we can draw two major conclusions. One is related to the fluid film characteristics between a cylinder block and a valve plate and the other is related to the average leakage that is determined by the pressure gradient and the clearance near the discharge port. The numerical results of cylinder block dynamics were compared with the experimental results using eddy-current type gap sensors those are fixed at a pump housing.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 하계학술대회 논문집 A
• /
• pp.266-268
• /
• 1998

The linear MHD(magnetohydro-dynamic) machine obtains the linear motion by replacing the solid conducting secondary of LIM with the ionized gas, plasma or the liquid metal. The electromagnetic pump which is a kind of MHD machine is divided into induction pump and conduction pump. This paper shows the classification and development trends of MHD machines and the characteristics of double sided flat linear induction pump (DFLIP).

• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 2003년도 유체기계 연구개발 발표회 논문집
• /
• pp.353-360
• /
• 2003

Hydraulic performance and cavitation characteristics of fuel pump in turbo-pump were studied experimentally. The fuel pump has a centrifugal impeller with a separate inducer. In this paper, flow characteristics of inducer and impeller was experimentally investigated separately and together. Especially static pressure distribution of Inducer was examined in non-cavitation and cavitation conditions.

• Journal of Advanced Marine Engineering and Technology
• /
• 제28권8호
• /
• pp.1203-1210
• /
• 2004

It was reported recently that the pump head degradation near the best efficiency point from single-phase flow to the break-down due to air entrainment became less in a screw-type centrifugal pump than in a general centrifugal pump. In this paper, I carried out internal pressure measurements and visualizations, and investigated the various physical phenomena occurring inside a screw-type centrifugal pump operated in air-water two-phase flow. The results could give some characteristics about the degradation of pump performance on air-water two-phase flow.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회B
• /
• pp.2763-2768
• /
• 2007

Recently, as the semiconductor production technology develops, there has been growing interest in the cooling system using micro fluid pump. Among the various types of micro fluid pump, the valve-less diffuser/nozzle has been extensively studied in recent years. However, the flat-walled diffuser/nozzle flow has not been clearly looked into due to its non-linear characteristics. In this paper, the flow characteristics of the flat-walled diffuser/nozzle have been analyzed using similitude model and simulations. Similitude models are designed so that the flow pattern is same as that of 1/10 scale flow by using high viscous fluid as working fluid. The results are compared to the simulations. It is shown that the flow characteristics of 2D simulation are different from 3D simulations at high Re region, and the measured pump efficiency is highly dependent on the pressure difference as well as the channel geometry. From these results, the desirable conditions for the efficient pump is discussed.