• Journal of Advanced Marine Engineering and Technology
• /
• v.28 no.7
• /
• pp.1072-1081
• /
• 2004

This paper is to investigate on the effects of the hole size of spring type EFV(excessive flow valve) for automobiles The analytical and experimental methods were employed to measure the discharge coefficient. choked flowrate and Pressure wave in a bombe, line and vaporizor The size of EFV was determined to meet the legally permitted limits with the capacity of engine displacement up to 2000cc, according to the obtained discharge coefficient. The Purpose of this paper is 1) to find causes of bad acceration performance in LPG engines 2) to find optimal design determination of spring coefficient and orifice hole size of excessive flow valve in LPG engine 3) to find pressure wave of bombe, line and vaporizer through expeimental verification. Experimental results indicated that increase of orifice size 0.5mm to 1mm be caused to increase discharge coefficient, and choked flow rate and decrease operation range of difference pressure wave.

• Nuclear Engineering and Technology
• /
• v.53 no.6
• /
• pp.1756-1768
• /
• 2021

The containment filtered venting system (CFVS) filters the atmosphere of the containment building and discharges a part of it to the outside environment to prevent containment overpressure during severe accidents. The Korean CFVS has a tank that filters fission products from the containment atmosphere by pool scrubbing, which is the primary decontamination process; however, prediction of its performance has been done based on researches conducted under mild conditions than those of severe accidents. Bubble behavior in a pool is a key parameter of pool scrubbing. Therefore, the bubble behavior in the pool was analyzed under various injection flow rates observed at the venturi nozzles used in the Korean CFVS using a wire-mesh sensor. Based on the experimental results, void fraction model was modified using the existing correlation, and a new bubble size prediction model was developed. The modified void fraction model agreed well with the obtained experimental data. However, the newly developed bubble size prediction model showed different results to those established in previous studies because the venturi nozzle diameter considered in this study was larger than those in previous studies. Therefore, this is the first model that reflects actual design of a venturi scrubbing nozzle.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.9 no.5
• /
• pp.75-81
• /
• 2001

This paper presents the atomization characteristics of single hole injector in the direct injection type diesel engine. The spray characteristics of fuel injector such as the droplet size and velocity were measured by phase Doppler particle analyzer. In this paper, the atomization characteristics of fuel spray are investigated for the experimental analysis of the measuring data by the results of mean diameter and mean velocity of droplet. The effect of fuel injection pressure on the droplet size shows that the higher injection pressure results in the decrease of mean droplet diameter in the fuel spray. The minimum size of fuel spray droplet appears on the location of 40mm axial distance from nozzle exit of diesel injector. Based on the experimental results, the correlation between the droplet diameter and mean velocity of the diesel spray due to the change of axial and radial distance from the nozzle tip were investigated.

• Computers and Concrete
• /
• v.16 no.1
• /
• pp.37-48
• /
• 2015

Alkali aggregate reaction affects numerous civil engineering structures and causes irreversible expansion and cracking. This work aims at developing model to predict the potential expansion of concrete containing alkali-reactive aggregates. First, the paper presents the experimental results concerning the influence of particle size of an alkali-reactive aggregate on mortar expansion studied at 0.15-0.80 mm, 1.25-2.50 mm and 2.5-5.0 mm size fractions and gives data necessary for model development. Results show that no expansion was measured on the mortars using small particles (0.15-0.80 mm) while the particles (1.25-2.50 mm) gave the largest expansions. Finally, model is proposed to simulate the experimental results by studying correlations between the measured expansions and the size of aggregates and to calculate the thickness of the porous zone necessary to take again all the volume of the gel created by this chemical reaction.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.8
• /
• pp.1121-1126
• /
• 2006

Methanol oxidation effect on carbon supported Pt was investigated as a function of Pt content in a sample which is closely correlated with Pt particle sizes. After prolonged methanol oxidation the Pt particle size did not change within the experimental error ranges. The $^{13}C$ chemical shift and linewidth of CO adsorbed on Pt show non-linear behavior simply due to the Pt particle size difference. The Pt size variation difference between this work and the previous reports of the particle growths is explained by the experimental temperature difference.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 1995.06a
• /
• pp.100-123
• /
• 1995

The relationship between plastic deformation and crystal grain change in warm forging processes of SM100 carbon steel is studied. If the carbon steel is deformed in warm forging temperature (about recrystallization range), the crystal grain and cementite of the internal part are changed, so material properties are changed. Some experimental values, such as the elliptic degree of cementite, the grain size of cementitie and ferrite grain size, are investigated. When the plastic deformation proceeds, the elliptic degree of cementite becomes large, the grain size of cementite particle is small, and the size of ferrite grain appears fine by recrystallization. The elliptic degree of cementite has a considerable effect on formability. The distribution of effective strain in the forging is calculated by the rigid visco-plastic FEM analysis. The effective strain distribution obtained from the FEM simulation is compared with the experimental result. At effective strain 0.3 dynamic recovery and dynamic recrystallization begin, over 2.5 the organization of material has better quality that is suitable for the following cold forming.

• Journal of Biosystems Engineering
• /
• v.17 no.4
• /
• pp.363-369
• /
• 1992

The aim of this study was to examine the blurring effects on performance of the experimental fruit grader in grading Fuji apples by size and coloration of the whole surface of individual apples. The grader consisted of a black/white image prcessing system, one camera, and utilized the algorithm developed for high speed sorting in the previous study. The results are summarized as follows : 1. With the algorithm developed in the previous study, it took 0.27~0.33 second in analyzing the size and coloration of an apple, and relative errors were within 3% for size and 1.3% for coloration. 2. The effect of blurring increased linearly with the conveying speed of apple and showed more significant effect on detection of coloration than on determining of size. 3. Considering the blurring effect, capacity of the experimental fruit grader was estimated to 7,500 apples per hour.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2010.05b
• /
• pp.67-68
• /
• 2010

Recently, there were not enough studies regarding the mix adjustment and changes of normal physical properties of slump flow type concrete in domestically. Therefore in this paper, it is aimed securing the fundamental data about flow its mix design method by experimental research. The experiment includes the adjustment of the way for slump flow type concrete by the variation of size of coarse aggregate. In the result, it is advisable raising the ratio of fine aggregate and unit water amount by considering the specific surface when increasing the Gmax size.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.6
• /
• pp.164-169
• /
• 2018

In this study, the effect of the size of the specimen on the apparent resistivity was investigated at the laboratory level for electrical resistivity. The specimens were measured for apparent resistivity by fabricating specimens with different sides and heights. Experimental results show that the apparent resistivity increases as the side and height of the specimen become smaller. Also, it was confirmed that the influence of the size of the specimen on the electrical resistivity measurement was not linear.

• Fashion & Textile Research Journal
• /
• v.24 no.6
• /
• pp.766-774
• /
• 2022

In this study, the fit of commercial sports bras was analyzed according to various design variations, focusing on the shape of the shoulder strap, which is known to cause great discomfort in wearing sports bras. Experimental clothes were set to four commercially available sports bras with different shoulder strap shapes. The results showed that, in "size suitability," the overall satisfaction with experimental clothing B, of which the shoulder strap can be adjusted, was the highest, especially for "underbust circ. fit," "bust circ. Fit," and "shoulder strap length." In the "Shape suitability" and "Wearability" sections, experimental clothing B also showed the highest satisfaction and the shoulder strap adjustment device did not negatively affect wearing satisfaction. In the question on "side wings rolled up," experimental clothing A also received a relatively good score, which is due to its long front length. In the "Compression of the front center" section, the responses for experimental clothing A and B were "appropriate" and for C and D, they were "pressurized." In "motion suitability" as well, satisfaction with experimental clothing B was the highest, followed by experimental clothes A, C, and D. In the "body shape correction" section, clothing B elicited the highest satisfaction, followed by experimental clothes A, C, and D, in that order. Overall, it is recommended that shoulder straps be applied with adjustable straps for the comfort of the shoulder area while wearing sports bras.