• 유체기계공업학회:학술대회논문집
• /
• 2003.12a
• /
• pp.107-114
• /
• 2003

The influence of property difference in refraction index on micro PIV measurement of two-fluid flow in a microchannel was analyzed. The difference of measurement planes in two fluids would bring misunderstanding of the physics. The objective-imaging system for two-fluid flow measurement was presented, and the condition for measurement of valid velocity profile across two-fluid interface was derived. A micro PIV experimental system was set up to measure two-fluid flow inside a Y-shape microchannel. Under the conditions, three cases of two-fluid flow of glycerol solutions at different concentration (${\phi}$), e.g., (${\phi}=0\;and\;{\phi}=0.2,\;{\phi}=0.1\;and\;{\phi}=0.5,\;{\phi}=0\;and\;{\phi}=0.6$, were measured. Close agreement of experimental and numerical results was found.

• Journal of muscle and joint health
• /
• v.23 no.2
• /
• pp.84-94
• /
• 2016

Purpose: This research aimed to identify levels of nurses' perception and practice of fluid intake and output (I & O) measurement and to explore the relationship between perception and practice of it. Methods: Using a cross-sectional survey design, 195 nurses who practiced fluid I & O measurement were recruited from a general hospital. Nurses who agreed to participate in this study completed a structured study questionnaire to assess their levels of perception and practice of fluid I & O measurement. Results: A level of perception of I & O measurement was high (3.46 points out of 5), and scores for 3 subdomains of I & O (importance, accuracy, and efficacy) were evenly high. The level of practice of I & O was fairly high (3.76 points out of 5). Perception and practice of I & O were highly correlated (r=.73, p<.001). Conclusion: Nurses seem to have higher levels of perception and do practice fluid I & O measurement correctly. In order to have reliable and valid I & O measures, nurses need to have continuous education on I & O measurement based on clinical guideline to utilize it as an invaluable clinical instrument.

• Korean Chemical Engineering Research
• /
• v.40 no.6
• /
• pp.676-680
• /
• 2002

The specific gravity meter is the instrument used to measure the density of fluids under the reference conditions and it can be widely used in industrial areas, especially in massive flow rate natural gas industry. This study has been carried out in an attempt to improve measurement accuracy of natural gas flow rate calculation, providing the adequate installation and proper operation conditions of specific gravity meter. The test results are 1) the density measurement errors in case of using methane and standard gas as calibration gases are smaller than using methane and nitrogen gas, 2) the periodical calibration to maintain accurate density measurements is essential, and 3) the specific gravity meter is sensitive to changes of environmental conditions, especially environmental temperature surrounding the specific gravity meter.

• Journal of Magnetics
• /
• v.22 no.2
• /
• pp.281-285
• /
• 2017

To suppress the wall slip effect and improve the yield stress measurement precision of magnetorheological fluid, measurement disks with different grooves are first manufactured. Then, the influence of groove characteristics on the yield stress of magnetorheological fluid is investigated by the method of experiments. Finally, the optimization wall grooves of measurement disks are obtained, and the yield stress of a self-prepared magnetorheological fluid is measured. Results indicate that the groove type and groove width have a slight influence on the shear yield stress, whereas the measured yield stress increases with enhanced groove density, and the optimized groove depth is 0.3 mm. The measured shear yield stress of self-prepared MR fluid can be improved by 18 % according to the optimized grooved disks, and the maximum yield stress can reach up to 65 kPa as the magnetic flux density is 0.5 T.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.30 no.3
• /
• pp.207-211
• /
• 2010

In this paper, the fluid AID(acoustic inspection device) was developed to measure SOS(speed of sound) since fluids used in most of industrial fields have different properties and its equipment is highly expensive. From AID developed, it is intended to get potentially the capability to distinguish the kind of fluid using the measurement by the SOS at various fields. In order to measure the sound speed of specific fluids, the measurement system and ultrasonic sensors are composed. The fluid used in the experimental work are soybean oil, glycerin, diesel oil and the error of time difference due to the container wall is extracted for preliminary experiment. As results, the variations of sound speed according to the temperature change of target fluid were analyzed and the polynomial equations were proposed.

• Korean Chemical Engineering Research
• /
• v.47 no.5
• /
• pp.565-571
• /
• 2009

This study was conducted to evaluate hydrocarbon and water dew points of natural gas. For this purpose, algorithm of suppressing divergence was devised to evaluate hydrocarbon dew point up to near critical point and algorithm for finding water dew points lower than that of hydrocarbon, which cannot be calculated by commercial dew point program, was developed. The evaluated values were compared to commercial program and ISO reference values, and the results showed that deviations were zero.

• Korean Chemical Engineering Research
• /
• v.47 no.5
• /
• pp.599-607
• /
• 2009

This study was conducted to derive the five correlations which could predict specific gravity(or heating value), compression factor, density, etc., if we know heating value or specific gravity only. To make a sufficient number of raw data for regression, SGERG EOS was modified into equation of heating value. Based on these raw data, five correlations were obtained and the uncertainties of the correlations were evaluated. The results showed that the uncertainties were near 0.1% in most conditions of natural gas and so the correlations could be used in natural gas industry and academic fields.

• The KSFM Journal of Fluid Machinery
• /
• v.3 no.3 s.8
• /
• pp.25-30
• /
• 2000

Thermodynamic method of pump performance measurement calculates pump efficiency and flowrate by measuring fluid temperature increase and pressure rise through the pump. The theory of this method is investigated and precise comparison experiment with classical hydraulic method was conducted to verify the accuracy. Classical hydraulic pump performance measurement results and Yatesmeter results based on the thermodynamic method showed good agreement in measured performance.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.11 no.2
• /
• pp.111-118
• /
• 2003

Recently, environmental damage to urban area becomes serious problem due to the exhaust emissions by increasing the number of vehicle. Especially, exhaust emission from diesel vehicles are blown to be harmful to human health and environment. Photoacoustic Spectroscopy system is very useful technology for simultaneous and continuous measurement of the various components of the automotive exhaust gas. In this study, in order to reduce emission gases from automobile, we tried to develop the measurement system of Photoacoustic Spectroscopy. To improve performance of high sensitive Photoacoustic Spectroscopy system for automotive exhaust emissions, the shape of Photoacoustic Spectroscopy cell was optimized to use the flow analysis. And Exhaust emission data of the 1,500cc gasoline engine was fixed the working fluid. The characteristics of fluid flow for cell were analyzed by various conditions in detail.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.26 no.6
• /
• pp.1016-1025
• /
• 2002

This paper deals with the measurement of the fluid viscosity by using the torsional vibration of a circular rod excited by a torsional vibrator at one end. The effect of an adjacent viscous fluid on the torsional vibration of the rod has been studied theoretically and expressed in terms of the mechanical impedance. The theoretically-obtained trend that the mechanical impedance is proportional to the square root of the viscosity times the density of the fluid has been confirmed by the impedance measurement. The paper demonstrates that a torsionally-vibrating rod can be used as a sensor to measure the viscosity of a fluid.