• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2632-2637
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• 2007

Rotary performance and flow resistance induced by each element in suction nozzle of a vacuum cleaner with a double-blade rotary fan are investigated numerically and its relation with flow-induced noise and rotary performance is examined. Flow resistance and vorticity in suction nozzle are calculated and it is found that they are closely related with flow-induced noise. Gap between double blades, adoption of cross-flow fan, enlargement of flow inlet area, and optimization of blade number are tested for noise reduction. Finally, the effects of each method are verified experimentally. It is found that several combinations of the proposed methods can be adopted for noise reduction although the degree of reduction is not much.

• The KSFM Journal of Fluid Machinery
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• v.15 no.3
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• pp.25-31
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• 2012

A computational study on the improvement of the pressure loss of intake system, which is located at engine manifold of the combat vehicle, has been conducted using a finite-volume-based, Reynolds-Averaged Navier-Stokes (RANS) solver. The computational result of the pressure loss through the air cleaner is in good agreement with equivalent experimental data. A parametric study was done for improving of the pressure loss of intake system over the baseline case. The effects of five primary parameters such as the height of inlet, the width of interconnection pipe, the shape of drain chamber and the diameter of filter housing were considered in this study. Consequently, this computational investigation can contribute to finding an optimal guideline for the idea of improvement in the pressure loss of intake system.

• Clean Technology
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• v.9 no.2
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• pp.63-69
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• 2003

The metal finishing industry generates a variety of pollutants such as acidic or alkaline wastewater, chromic compounds, cyanide, heavy metals, and toxic materials. Especially, zinc plating process is one of the processes which cause serious environmental problems. In this study, we applied the proven optimum technology to important unit processes in terms of implement effects through the process diagnosis and analysis. This study aimed to improve the working environment and the environmental pollutions in zinc plating process.

• Korean Business Review
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• v.21 no.1
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• pp.1-17
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• 2008

This article examines the establishment of the game theoretic model for the cleaner vehicles and analyzes the established model. We discuss the way to represent the players' preferences over the outcomes to make the model applicable in real practice. In this article we employ the real data to represent the preferences. In the analysis of the model we consider various scenarios and discuss how we can use GAMBIT, which is a game theory analysis software, to find solutions in each proposed scenario.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.935-938
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• 2007

In suction nozzle of a vacuum cleaner, where flow-induced noise is generated mainly by flow resistance, several ideas to reduce noise are investigated. To increase fan performance, blade number is optimized and a centrifugal fan is replaced by a cross-flow fan, In addition, gear ratio of fan to drum brush is changed. It is found that fan performance is increased by adopting these methods. Next, the blade height of the fan is decreased to reduce sound pressure level, which causes inevitably decrease in fan performance. Eventually, flow-induced noise is reduced by 6.3 dBA in its overall level with the fan performance maintained.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.208-211
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• 2006

Flow resistance induced by each element in suction nozzle of a vacuum cleaner with a rotary fan is investigated numerically and its relation with flow-induced noise is examined. Flow resistance and vorticity in suction nozzle are calculated and it is found that they are closely related with flow-induced noise. From numerical results, it is suggested that reduction of flow resistance effectively increases all-suction performance and decreases sound pressure level of noise generated in the suction nozzle.

• Journal of Korean Society for Quality Management
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• v.27 no.3
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• pp.170-188
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• 1999

In all activities of companies, manufacturing processes are one of those which have the worst effect on our environment. So manufacturing companies have taken the necessary steps to comply with environmental regulations. But, most of them focused on the environmental standard control equipments, using ‘end-of-pipe techniques’ that can obtain the desired reductions in a short time-period. But these methods are essentially symptomatic treatments and are not enough for sustainable development. 3M's solution is the ‘cleaner techniques’which emphasize prevention rather than corrective control. This paper examines the concept of cleaner techniques and the environmental management system of 3M - how to conduct technological innovation to prevent generation of pollution and waste at the source under the 3P program.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.63-68
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• 2001

A numerical analysis to predict the flow characteristics in turbo fan for vacuum cleaner has been performed by using CFD. The rotating reference frame method is applied to compute the impeller-diffuser interaction and the characteristics of two models, 460 and 380, are calculated for various rotating speeds and flow rates. The flow in impeller, diffuser and return channel is assumed as steady and compressible. STAR-CD with k- $\epsilon$ turbulence model is used to solve the Navier-Stokes equations. Computed relative velocity, absolute pressure and flow angles are shown and compared with measurement results. The good agreement between the predictions and measurement results confirms the validity of this study.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.54-60
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• 2001

In this research, we developed a computer code that designs a compressor impeller, which serves as an essential component of a vacuum cleaner, and predicted its performance. The TEIS model originally developed by Japikse(1985), and the mean line analysis m combined to design the centrifugal impeller optimally. In this program the inlet geometry is designed by using the mean line analysis, and with assumption of resonable exit blade angle, the optimal geometry is searched by means of TEIS model and iterative scheme. The performance of designed impeller was compared with experimental data, and the far-field noise by the rotating impeller is also predicted.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.10a
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• pp.29-32
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• 2003

Multi -walled carbon nanotube(MWNT)/poly(methyl methacrylate) composites were fabricate d through film casting. Manufacturing process was established using a ultrasonic cleaner and a homogenizer. Acetone was used as a solvent to melt PMMA and mix with MWNT. The ultrasonic cleaner performed an important role in producing MWNT/MMA nanocomposites. Ultrasonic energy was utilized to disperse MWNT in acetone. Also, melting PMMA in acetone and mixing MWNT and PMMA were achieved using the homogenizer. It was confirmed that the nanohlbes were well dispersed in PMMA according to SEM images.