• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.11a
• /
• pp.38-39
• /
• 2013

In this study, in regard to fiber reinforced mortar mixing steel fiber and 4types of organic fiber, impact test was carried out. Because to predict fracture reduction performance with flexural, tensile strength when types of fiber were different as impact reduction performance of concrete is closely related with toughness such as flexural strength, tensile strength and fracture energy etc. As a result, enhancement of toughness by fiber reinforcement controls the spall of rear. On the other hand in case of steel fiber relatively turned up high toughness in appropriate load compared with organic fiber but in same mixing rate, impact reduction performance by projectile showed low performance due to few number of an individual of mixing.

• Journal of Advanced Marine Engineering and Technology
• /
• v.32 no.5
• /
• pp.663-669
• /
• 2008

A rapid growth of automobile industry has become a major cause for the environmental pollution of big cities, which has driven the emission regulation into extreme. The study of alternative fuel is one of the many researches for improving car emissions. In this study, the effect of an ethanol mixing rate on the engine performance of exhaust emissions, fuel consumption and a maximum torque is assessed for a gasoline engine without any retrofit. The result shows that maximum torque is not reduced in the range of ethanol mixing rate of 10 to 15%. CO and NOx is reduced with the increase of ethanol mixing rate and the fuel consumption remains in similar level.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1996.06c
• /
• pp.1117-1125
• /
• 1996

A low-cost and precise metering device, which is suitable to automatic mixing of nutrient-solution for hydroponic culture, was developed for small-scale growers. The metering accuracy of the metering device developed was compared with commercial metering pumps. The mixing performance through the control of EC and pH was also evaluated. The accuracy of the metering device in terms of the full -scale error was $\pm$0.3% , which was much better compared to $\pm$2.45% and $\pm$1.38% for the two types of commercial metering pumps. The mixing system of nutrient-solution with the metering device showed a satisfactory control performance with the accuracies of $\pm$0.05mS/cm and$\pm$0.2pH for EC and pH, respectively.

• Korean Chemical Engineering Research
• /
• v.60 no.3
• /
• pp.468-471
• /
• 2022

The influence of the central axis and the strut supporting the helical ribbon was investigated in a helical ribbon impeller mixing tank through experiments and visualization. As a result, the strut, which is in the transverse direction, turned out to have a significant adverse effect on the mixing performance such as the occurrence of incomplete mixing region from the change of the liquid level. In contrast, the central axis, which in the longitudinal direction, did not show much adverse effects.

• The KSFM Journal of Fluid Machinery
• /
• v.16 no.1
• /
• pp.47-55
• /
• 2013

In the present study, a numerical simulation to analyze mixing performance inside an industrial mixer was investigated for various geometry of turbine impellers. Various pitching angles and various types of turbine blades were considered in the simulation. In order to model the rotation of impeller, the Multiple Reference Frames (MRF) technique was used. For evaluation of the effect of various shapes on the mixing performance, dimensionless coefficient such as flow coefficient, circulation coefficient, power coefficient, pumping effectiveness and circulation effectiveness were used. From the results, the effect of pitching angle of a pitched turbine impeller was to give best pumping effectiveness around $30^{\circ}$ pitching angle, whereas best circulation effectiveness around $65^{\circ}$ pitching angle. Dual pitched turbine impeller showed best performance in both pumping effectiveness and circulation effectiveness among impeller types considered in the present study.

• Journal of the Korea Convergence Society
• /
• v.9 no.10
• /
• pp.237-242
• /
• 2018

A micromixer is a component of a lab-on-a-chip or microfluidic device that mixes two or more chemicals together(convergence). The purpose of this study is to assess the performance of passive micromixer of various shapes. Six shapes of micromixers were compared and three dimensional modeling was carried out to have the same hydraulic diameter. The commercial code, ANSYS Fluent, was used to simulate the internal mixing flow. A numerical analysis method is described in detail in this paper. The performance of the micromixer was compared with the mixing index and pressure drop. Consequently, the CDM-8T shape showed reasonable mixing performance and relatively low pressure drop.

• Journal of environmental and Sanitary engineering
• /
• v.10 no.2
• /
• pp.30-35
• /
• 1995

In this research effect of physicochemical parameter on flocculation using PASS-100 were evaluated. pEt flocculant dosage, mixing intensity and detention time were adopted as experimental variables. The physicochemical parameter( p% mixing intensity and mixing time ) were important Parameter on flocculation performance. Effluent pH range for effective flocculation was 4.5-7. Optimum Gt$_{d}$ range was 20,000-30,000 and its range similar to alum flucculation. Rapid mixing was very important parameter to floe formation in PASS- 100 flocculation. Whereas, slow mixing did not affect to the removal efficiency at settling time for 30minute or more.

• Proceedings of the KSME Conference
• /
• 2001.11b
• /
• pp.557-562
• /
• 2001

Fluid mixing is ubiquitous and essential in many natural and industrial systems. Understanding the mixing processes that occur in these diverse system is essential for predicting many aspects of practical importance. The objective of this study is to perform the experimental and numerical investigation of the flow and mixing in a static mixer. Three different types of mixing elements, Sulzer, SSM and PPM were used. Glycerin and hydraulic oil were used as mixing fluids. Pressure drop was measured using a manometer.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.11
• /
• pp.3021-3031
• /
• 1994

Experiments have been performed to find out the effect of the mixing port length of Y-jet atomizers on the spray performance, using air and water as the test fluids. Water and air flow rates and drop sizes were measured at each injection pressure condition for different mixing port length. The air flow rate was almost unaffected by the change of the mixing port length. However, the water flow rate was relatively susceptible to the change of the mixing port length. The mixing point pressure was very much influenced by the mixing port length. Variations of spatial distribution of Sauter Mean Diameter (SMD, $D_{32}$) and the cross-section-averaged SMD ($D_{32,m}$) with different mixing port length and air/water mass flow rate ratio were examined. Generally, when the mixing port length was reduced, the mean drop size decreased and became spatially even.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.18 no.12
• /
• pp.999-1006
• /
• 2006

A study of temperature profiles in mixing zone of AHU (air handling unit) can contribute greatly to enhance performance of AHU system, so the study on the temperature distribution between RA (return air) and OA (outdoor air) is important to analyze the mixing characteristics in a mixing zone of AHU. Accordingly, the temperature profiles during RA (return air) and OA (outdoor air) supply process into mixing zone of AHU with an air mixer are studied experimentally. The effect of air mixer, OA temperature and RA/OA flow rate are studied in detail. In this study, the results show that the mixing efficiency is all high for installed the air mixer. The more OA temperature increase and OA flow rate decrease, the more mixing efficiency is high.