• Water for future
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• v.40 no.12
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• pp.30-37
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• 2007

• Water for future
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• v.49 no.12
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• pp.23-31
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• 2016

• Proceedings of the Korea Water Resources Association Conference
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• 2002.05b
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• pp.940-945
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• 2002

• International Journal of Advanced Culture Technology
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• v.9 no.3
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• pp.360-366
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• 2021

In this study, we tried to examine how the kinking of the fire hose affects the time taken for initial water discharge by measuring and analyzing the time taken for initial water discharge with different number of kinks at different locations of the hose. The average time taken for initial water discharge was obtained by measuring the time in the unkinked state of the fire hose. Based on this standard, we conducted the experiment by selecting the kinking locations in the hose near the water outlet and nozzle, and setting the number of kinks to 3, 6, 9, and 12. The results of this study are as follows: First, if the fire hose has 5 kinks or more near the nozzle, no water was released. Second, when comparing the case of no kinks and 4 kinks near the nozzle, there was no significant difference in the time taken for initial water discharge. Third, when the fire hose was kinked 10 times near the outlet, the time required for initial water discharge increased by 1.62 seconds on average compared to the case with no kinking, but there was no problem with water discharge. Lastly, regarding the kinking locations of the fire hose, it was found that the greater the number of kinks near the nozzle than near the outlet, the greater the effect on the discharge. As a result, it is concluded that it would be preferable to install non-kinking devices near the nozzle of the fire hose.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.4
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• pp.1501-1509
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• 1996

Differential pressure devices such as an orifice and Venturi are widely used in the measurement of flow rate of fluid mainly due to cost effectiveness and easy installation. In the current study, the viscoelastic effect on discharge and loss coefficients of those flow meters were investigated experimentally. Aqueous solutions of Polyacrylamide (200, 500, and 800 ppm) as viscoelastic fluids were used. Discharge coefficient of an orifice for viscoelastic fluids increased significantly up to approximately 15-20% when compared with that for water, while loss coefficient decreased up to 10-25% depending on the diameter ratio, .betha.. Also, pressure recovery for viscoelastic fluids was extended much longer than that for water. On the other hand, discharge and loss coefficients of Venturi for viscoelastic fluids were found to be strongly dependent on the Reynolds number. In both flow meters, the concentration effect for discharge and loss coefficients was not observed at more over than 200 ppm of aqueous solution. Conclusively, orifice and Venturi flow meters should be calibrated very carefully in the flow rate measurement for viscoelastic fluids.

• Fire Science and Engineering
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• v.26 no.3
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• pp.67-72
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• 2012

Indoor fire hydrant facilities and sprinkler system applied to the initial fire suppression for buildings' interior fire are pivotal roles in extinguishing the fire in the early stage. The roof shapes of recent buildings combined with distinctive local culture and design are being constructed. Distinctive roof forms, i.e. gable roof buildings are planned and built, View point planning with the roof gardens also restricts measurement of the discharge pressure on the indoor fire hydrant, It is too narrow to gauge the water discharge pressure with deploying up to 5 water hoses. To resolve these problems improvement for the efficient management of indoor fire hydrant system and the effective early stage flame extinguishment is suggested.

• Journal of Korea Water Resources Association
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• v.43 no.12
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• pp.1039-1050
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• 2010

Relative accuracy of six discharge measurement methods-velocity-area method, rod-float method, ADCP moving-vessel method, ADCP fixed-vessel method, electromagnetic wave surface velocimeter (EWSV), LSPIV- is evaluated by comparing discharges measured by them with dam released discharges. Data from 39 times of concurrent discharge measurement campaigns are analyzed. Except the rod-float method, measured discharges show absolute errors less than 6.2% with dam discharges. When the four methods is evaluated by being compared with discharges measured with the conventional velocity-area method, discharges with electromagnetic wave surface velocimetry shows 7.35% of absolute errors and other three methods shows absolute errors less than 6%. The rod-float method, which shows large discrepancy compared with dam and velocity-area method, need complementary verification.

• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.342-346
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• 2006

The method presented is also efficient and applicable in estimating the discharge in high flows that are very difficult or impossible to measure before, due to technical or theoretical reasons. The method can drastically reduce the time and cost of measurement, regardless of the irregularity in the geometrical shape. With Microwave Water Surface Velocity Meter, An entropy based method for determining the discharge in the rivers can be used to develop real-time discharge measurement system (RDMS) which can carry out the real-time inflow hydrograph.

• Journal of Wetlands Research
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• v.12 no.1
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• pp.95-103
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• 2010

Discharge data examine the process of hydrologic cycle and used significantly in water resource planning and irrigation and flood control planning. However, it needs lots of time and money to get the discharge data. So discharge rating curve is usually used in converting discharge data. Therefore reliability of discharge rating curve absolutely depends on quality of discharge data. Many engineers who study hydrologic engineering make high quality discharge data to develop reliable discharge rating curve. And they carry out research on standard and method of discharge measurement, and equipment improvement. Now various flow meters are utilized to make discharge data in Korea. However, accuracy of equipment and experimental research data from measurement are not enough. In this paper, constant discharge flowed through standard concrete channel, and the velocity is measured using various flow meters. Also Discharge is calculated by measured data to compare and analyze. The equipment for the experiment is Price AA(USGS Type AA Current meter), flow meter, ADC, C2 small current meter, flow tracker, Electromagnetic current meter. The discharge got form various flow meters which are widely used for discharge measurement. The various depths of water were examined and compared such as 0.30 m, 0.35 m, 0.40 m, 0.45 m, 0.50 m, 0.55 m. The experiment progresses a round-measurement on 6-case. Wading measurement(one point method : the 60 % height in surface of the water) was applied to improve creditability and accuracy among measurement methods. USGS Type AA current Meter, Flow Meter, ADC, C2 Small Current meter got the certificate of quality guaranteed. So the results of experiment were used to compare discharge. The Results showed the difference based on USGS Type AA current Meter at average discharge and velocity. Electromagnetic current meter made differences over $\pm$ 10 % and Flow Meter made differences under $\pm$ 10 %. Also ADC, Flow Meter, C2 Small Current meter made differences under $\pm$ 5 %.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.1
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• pp.109-114
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• 2012

Stage-discharge relationship is applied to convert water level into discharge at the auto-measuring station in many irrigation canals. The stage-discharge curve is very important for reliable application for the agricultural water management system. We made results of discharge measurement at 18 stations in the irrigation canal nearby the Idong reservoir from 2010 to 2011. Stage-discharge relationships for each 18 stations were drawn considering of different hydraulic and geometrical characteristics at each stations. R-squared over 0.91 at each stations show high reliability for application of these relationships.