• Korea-Australia Rheology Journal
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• 제20권4호
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• pp.197-211
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• 2008

The purpose of this study is mainly directed towards present of viewpoints on critical and commentary analysis on blood rheology, blood viscosity models, and physiological flow conditions. Understanding these basics is fundamental to meet the need for a sufficient and reliable CFD model of blood. Most of the used viscosity models on this manner have determined from parameter fitting on experimental viscosity data. Availability of experimental data from literature to define viscosity models of CFD analysis should be accurately chosen and treated in order to avoid any errors. Several basic gaps that limit the CFD model results are identified and given opportunities for future research.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권4호
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• pp.670-690
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• 2015

In this paper, numerical investigations for tank sloshing, based on commercial CFD package FLUENT, are performed to study effects of boundary layer grid, liquid viscosity and compressible air on sloshing pressure, wave height and rising time of impact pressure. Also, sloshing experiments for liquids of different viscosity are carried out to validate the numerical results. Through comparison of numerical and experimental results, a computational model including boundary layer grid can predict the sloshing pressure more accurately. Energy dissipation due to viscous friction leads to reduction of sloshing pressure and wave elevation. Sloshing pressure is also reduced because of cushion effect of compressible air. Due to high viscosity damping effect and compressible air effect, the rising time of impact pressure becomes longer. It is also found that liquid viscosity and compressible air influence distribution of dynamic pressure along the vertical tank wall.

• 한국건축시공학회지
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• 제3권3호
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• pp.121-126
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• 2003

This study investigated about several mix factors came up to drying shrinkage and carbonation of high flowing concrete using viscosity. The results are as follows; Drying shrinkage ratio of high flowing concrete using viscosity showed higher for early age, but lower than normal concrete as long age. Also, drying shrinkage ratio and reduction ratio of mass showed higher and relative dynamic modulus of elasticty showed lower as W/C was higher generally. And in case of high flowing concrete using viscosity, carbonation wasn't confirmed without the kinds of cement and viscosity except 50C.

• 한국조리학회지
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• 제8권3호
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• pp.267-278
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• 2002

단백질 함유량은 유색미가루가 밀가루보다 적지만 현미가루보다는 함유량이 많았고, 지방함량과 회분함량에서는 현미와 비슷하였다. 현미가루는 유색미가루보다 peak viscosity, holding viscosity, breakdown viscosity, final viscosity에서 높았을 뿐만 아니라 setback viscosity에서도 높았지만 유색미가루는 호화점도에서 현미가루 뿐만 아니라 밀가루보다도 월등히 낮았다. 현미가루와 흑미가루는 5.3~6.4%의 총 식이섬유를 함유하였으나 수용성 식이섬유의 함량은 낮은 반면 주로 불용성 식이섬유를 함유하였다. 건조면과 조리면의 cutting force는 현미가루와 유색미가루의 혼합비율을 높이면 감소하였고 조리면의 경우에는 찰흑미가루 10%와 화성현미가루 20%를 첨가했을 때 밀가루 100%로 만든 대조군과 큰 차이가 없었다. 국수의 기능성을 높이고 기호도를 향상시키기 위하여 현미가루와 유색미가루를 10~30%를 첨가하여 관능검사를 실험한 결과 현미가루 20%와 찰흑미가루 20%를 첨가한 국수가 가장 높은 관능적 평가를 받았다.

• Tribology and Lubricants
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• 제22권6호
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• pp.307-313
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• 2006

In this paper, a theoretical analysis is carried out to study the effect of viscosity variation with pressure in multiply grooved moving hydraulic spool valves. Analytical expressions for pressure distribution in the clearance and leakage flowrate are obtained solving one-dimensional Reynolds. For constant viscosity, an analytical expression for lateral force is also presented. The results showed that variation of viscosity with pressure affect highly on pressure distribution, leakage flowrate and lateral forces in hydraulic spool valves. Therefore additional intensive studies, including numerical analysis for two-dimensional Reynolds, should be required to investigate detailed lubrication characteristics of spool valves for high pressure.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.197-198
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• 2023

This study was conducted as part of research and development of high-strength grout. Accordingly, dolomite aggregate was used as a filler incorporated into the high-strength grout. Dolomite aggregate has a disadvantage of increasing the viscosity of the grout due to higher generation of fine powder than other aggregates. Accordingly, in this experiment, it was confirmed that the viscosity, flow time, and flow of high-strength grout change according to the volume composition ratio of dolomite aggregate and cement-based material. All experiments were conducted based on the Korean Industrial Standard KS F 4044, and the mixing factor was applied according to the composition ratio of the binder and the filler. In the experiment, the amount of fine powder contained in the dolomite aggregate rather than the silica sand used in the past is grasped, and after mixing with the grout accordingly, the mixture is proceeded to measure the viscosity in an unhardened state. In addition, the flow and flow time of the grout are evaluated according to the viscosity. As a result of the experiment, it was confirmed that the viscosity and flow time decreased and the flow increased as the volume composition ratio of the dolomite aggregate to the cement-based material increased.

• 한국식품영양과학회지
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• 제27권5호
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• pp.881-889
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• 1998

For the application of the commercially modified starch in frozen and retort foods, apparent viscosity and water loss were measured at each stages of heating, sterilization and freezing-thawing stages. Apparent viscosity showed the exponential increase with concentration and the slopes of apparent viscosity against concentration in the Firm-Tex(hydroxypropyl distarch phosphate), Hi-Flo(acetylated distarch adipate) and Colflo 67(acetylated distarch adipate) from waxy maize starch were higher than those of Amyloacetate M20(starch acetate) and X-amylo 250(distarch phosphare) from potato starch. In the presence of 1 or 2% NaCl, X-amylo 250 among modified starches showed the increase in water loss and the decrease in apparent viscosity, whereas Colflo 67, Hi-Flo and Firm-Tex were little affected by NaCl. In the presence of 1 or 2% sucrose, water loss and apparent viscosity of the modified starches were not affected. In the range of pH 4~8, water loss and apparent viscosity of the modified starches had no change but the differences were detected to some extent between each of heating, sterilization and freezing-thawing stages. In the apparent viscosity and water loss of the modified starches after 3 week storage from heating and sterilization, Hi-Flo, Amyloacetate M20 and X-amylo 250 were not changed at the storage period, and the overall acceptability of retort food containing the modified starches such as Firm-Tex and Amyloacetate M20 were favored more than others. In the apparent viscosity and water loss of the modified starches which have been frozen and thawed three times repeatedly, Colflo 67, Hi-Flo and Firm-Tex were not changed in freezingthawing, and the overall acceptability of frozen food containing Firm-Tex was most favored.

• Journal of Advanced Marine Engineering and Technology
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• 제7권2호
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• pp.15-21
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• 1983

Preparing for treatment and management of the emulsified fuel oil which will be generalized henceforth, this paper is an attempt to examine the viscosity-temperature characteristics of emulsified heavy fuel oil which is mixed with water and emulsifier in various mixture ratio by mechanical mixer. The experimental results are summarized as follows: 1. The viscosity-temperature characteristics of the emulsified C & B grade heavy fuel oil mixed with water of same or less weight, is changed according to log.log(v+0.6)=b-3.8log T. 2. The emulsifier has to be added to the emulsified A grade heavy fuel oil mixed with water of same or less weight, because it is instable. Especially if the emulsifier is sodium stearate, it is added more than 0.3% of the weight of oil and water. 3. In the emulsified A grade heavy fuel oil mixed with water and emulsifier, the higher the ratio of water addition becomes, the higher the viscosity is and the more the viscosity-temperature slope decreases. But the higher the ratio of emulsifier addition is, the more the viscosity-temperature slope increases. In this case, the linearity of viscosity-temperature characteristic curve is poorer than that of B and C grade heavy fuel oil. 4. In the emulsified A grade heavy fuel oil mixed with emulsifier of 0.3% or less, the emulsion type is O/W type when water addition ratio is 40%, but it is W/O type when it is 10%, 20%, 30% and 50%.

• Korea-Australia Rheology Journal
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• 제15권3호
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• pp.117-124
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• 2003

Elastohydrodynamic lubrication (EHL) film is measured under the condition of viscosity index improver added to base oil. In-situ optical contact method using the interference principle make the measuring resolution of ~5 nm possible and enables the measuring range all over the contact area of up to ~300 $\mu\textrm{m}$ diameter. What is more important to the developed method by the author is that the measurement of EHL film thickness is possible in the range from 100 nm to 2 $\mu\textrm{m}$, which is the regime of worst contact failures in precision machinery. Viscosity index improver (VII) is one of the major additives to the modem multigrade lubricants for the viscosity stability against temperature rise. However, it causes shear thinning effects which make the film thickness lessened very delicately at high shear rate (over $10^5 s^{-1}$) of general EHL contact regime. In order to exactly verify the VIIs performance of viscosity stability at such high shear rate, it is necessary to make the measurement of EHL film thickness down to ~100 nm with fine resolution for the preliminary study of viscosity control. In this work, EHL film thickness of VII added lubricant is measured with the resolution of ~5 nm, which will give very informative design tool for the synthesis of lubricants regarding the matter of load carrying capacity at high shear rate condition.

• 센서학회지
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• 제17권4호
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• pp.289-294
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• 2008

The purpose of this study is to materialize the viscosity sensor by using the SH-SAW sensor of which the center frequency is operated at higher than 50 MHz. In order to measure the viscosity, SAW sensor of which the center frequency is operated at 100 MHz is developed. By using the developed sensor, phase shift, delay time, insertion loss, and frequency variation are measured at different viscosity. The result shows that the phase shift difference between the viscosity variations is such that the difference between the distilled water and the 100 % glycerol solution is approximately $45^{\circ}$, the change of the insertion loss is approximately 9 dB, and the difference of frequency variation is approximately 5.9 MHz. Therefore, it is shown that viscosity of unknown solution can be measured with the surface acoustic wave sensor.