• 한국화재소방학회논문지
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• 제32권1호
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• pp.24-32
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• 2018

수리계산방식에 의한 설계는 전산프로그램을 사용하는 방식과 직접 설계자가 계산에 의하여 설계하는 방식이 있다. 전산프로그램을 사용하는 경우 필요한 조건을 입력하면 프로그램에 의해 마찰손실, 유량, 양정 등을 계산하여 주지만 기본적인 개념과 절차를 모르게 되면 계산값이 입력자마다 다를 수가 있어 절차상의 기준을 정하는 것이 필요하다. 설계자가 직접 계산하는 경우에도 동일하다. 따라서 설계면적 내에서 수리계산의 절차를 다음과 같이 제시하였다. 가지관에 설치되는 티의 등가길이는 방출구(Outlet)의 관경이 다를지라도 설치된 배관의 관경과 동일한 관경(Run)의 등가길이를 선택한다. 가지관 중간에 손실값이 큰 다른 헤드가 있더라도 말단에서부터 계산해온 압력이 더 크다면 말단헤드에서부터 계산해온 압력으로 헤드방출량을 계산한다.

• 한국정밀공학회지
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• 제18권6호
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• pp.127-132
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• 2001

An automatic design system for a hydraulic gate has been developed to cut down the time for the design calculation and to optimize its design. It is oriented to the radial gate which is the simplest, most reliable, least expensive and most widely used hydraulic gate. This system is composed of data input, strength computation and result display modules with databases of the properties of components and materials. In this development, the existing intricate design procedure has been changed to the straightforward procedure without assumption of weight. With this code, the design time of the radial gate could be reduced below one thirtieth in comparison with manual work and the optimum design could be accomplished easily.

• Geomechanics and Engineering
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• 제33권3호
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• pp.317-326
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• 2023

Accurately measuring the hydraulic conductivity of dredged slurry (HCODS) is a difficult task and usually requires highly developed experimental techniques. To resolve such problem, this paper presents a novel laboratory method, where a double drainage sedimentation test (DDST) is proposed to generate a downward seepage after the end of primary consolidation (EOP). Based on the established stress equilibrium equations, it is figured out that the determination of local hydraulic gradients requires the effective stress distribution to be measured. Accordingly, an additional single drainage sedimentation test (SDST) with the same initial water content is performed in the novel laboratory method, which can be utilized to establish the relationship between effective stress and water content for investigated slurry. Thus, HCODS can be determined via a pair of SDST and DDST, with the water contents after the EOP measured. The corresponding calculation procedure is given in details. With a simply-designed settling column, the hydraulic conductivity tests were performed on three types of dredged slurry. The results demonstrated the effectiveness of the novel laboratory method in measuring HCODS.

• 소음진동
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• 제10권4호
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• pp.623-628
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• 2000

This paper presents the automatic plumbness measuring system form improving the accuracy and working time for plumbness measuring of semi-umbrella type hydraulic turbine generator. It is general practice that rotating shaft should run within acceptable vibration limit. In order to obtain more accurate measuring data for single stage shaft on the semi-umbrella type, plumbness approach must be established carefully and accurately. Generally, present plumbness procedure is required several calculation algorithm, laser sensor and data acquisition devices. As a result of application to actual new system it is confirmed that working time could be saved over 80% and accurate measurement data could be acquired.

• 상하수도학회지
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• 제13권2호
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• pp.95-104
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• 1999

A simulation of water hammer, introduced by abruptly varied motion of a pumping machine, was performed at a one of typical pumping station in Korea. Impact of hydraulic structure such as check valve, pressure relief valve and air valve in mitigating water hammer effect was estimated gradually. Method of characteristic was employed for the effective calculation of discharge and head. The relationship between various hydraulic structures and flow was properly integrated on the base of the method of characteristic. The methodology in this approach can provide significant contribution in decision making procedure for the design of hydraulic structure at a typical pumping station in Korea.

• Nuclear Engineering and Technology
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• 제28권3호
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• pp.331-338
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• 1996

In the thermal-hydraulic design, the effect of fuel rod bow is quantified tv the rod bow DNBR penalty which is a key design parameter to assure the coolability of fuel assembly in the pressurized water reactor. In this work, a computer program for the evaluation of the rod bow DNBR penalty based on Westinghouse methodology is developed and its application procedure is proposed. The computer simulation is based on the Monte-Carlo method. The qualification of developed computer program is performed by a comparison of calculational result with that given by Westinghouse's document. A new application procedure is built using batch mean and batch standard deviation. The normality of sample population generated by the batch calculation is confirmed by means of a chi-square test for goodness of fit. On the view point of statistics it is effected that the more reliable design value may be produced by the new application procedure.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.498-507
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• 2008

The mixture of bentonite powder and water is generally used to maintain the stability of excavation surface during the construction of vertical cutoff walls. The filter cake on the sidewall surface is the result of filtration of slurry into the adjacent soil formation. The filter cake is believed to have a very low hydraulic conductivity compared to that of the cutoff wall. This paper evaluates hydraulic conductivities of bentonite filter cakes set up with three types of bentonites under various pressure levels. A modified fluid loss test was employed in this experiment. Theory of filtration process was reviewed to explain the procedure in the present experiment. Hydraulic conductivity of the filter cakes with consideration of the filter medium resistance was evaluated. The results of the experiment with two calculation methods and discussion are presented to show the efficiency of the modified fluid loss test.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1502-1511
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• 2008

The mixture of bentonite powder and water is generally used to maintain the stability of excavation surface during the construction of vertical cutoff walls. The filter cake on the sidewall surface is the result of filtration of slurry into the adjacent soil formation. The filter cake is believed to have a very low hydraulic conductivity compared to that of the cutoff wall. This paper evaluates hydraulic conductivities of bentonite filter cakes set up with three types of bentonites under various pressure levels. A modified fluid loss test was employed in this experiment. Theory of filtration process was reviewed to explain the procedure in the present experiment. Hydraulic conductivity of the filter cakes with consideration of the filter medium resistance was evaluated. The results of the experiment with two calculation methods and discussion are presented to show the efficiency of the modified fluid loss test.

• 소음진동
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• 제8권5호
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• pp.922-928
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• 1998

This paper presents the automatic alignment measuring system for improving the accuracy and working time of alignment of large vertical hydraulic pump turbine. It is general practice that rotating shaft should run within acceptable vibration limit. In order to obtain better run-out data of multi-stage rotor, careful and accurate alignment approach must be established. Generally, present alignment procedure are required several iterative works and so many manpower. Therefore, the new system has been developed using a vector calculation algorithm, laser sensor and data acquisition devices. As a result of appling to actual machines, it is confirmed that manpower is saved up to an average 90%.

• 한국소음진동공학회논문집
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• 제12권4호
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• pp.261-271
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• 2002

The fluid-elastic instability analysis of the U-tube bundle inside the steam generator is very important not only for detailed design stage of the SG but also for the change of operating condition of the nuclear powerplant. However the calculation procedure for the fluid-elastic instability was so complicated that the consolidated computer program has not been developed until now. In this study, the numerical calculation procedure and the computer program to obtain the stability ratio were developed. The thermal-hydraulic data in the region of secondary side of steam generator was obtained from executing the ATHOS3 code. The distribution of the fluid density can be calculated by using the void fraction, enthalpy, and operating pressure. The effective mass distribution along the U-tube was required to calculate natural frequency and dynamic mode shape using the ANSYS ver. 5.6 code. Finally, stability ratios for selected tubes of the CE type steam generator were computed. We considered the YGN 3.4 nuclear powerplant as the model plant, and stability ratios were investigated at the flow exit region of the U-tube. From our results, stability ratios at the central and the outside region of the tube bundle are much higher than those of other region.