• Elastomers and Composites
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• v.49 no.2
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• pp.149-154
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• 2014

Friction and abrasion behaviors were investigated for SBR rubber compounds reinforced by silica and carbon black. Knife-blade abrader, newly designed based on tearing energy theory, was utilized in order to evaluate the effect of frictional work on the wear rate of the rubber compounds. It was found that the power law relation between frictional work and wear rate worked, in which as the wear rate was increased as frictional work increased. The wear rate could be determined successfully using the knife-blade abrader in which a moving distance of the knife blade in the process of wearing was measured continuously, instead of intermittent measurements of weight loss by wear during experiment.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.6 no.4
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• pp.15-21
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• 2007

The effect of manufacturing parameters on friction characteristics of motorcycle break system was studied using a disk-on-pad type friction tester. Such parameters conditions have an effect on the frictional factor such as number of ventilated disk hole, applied load, sliding speed, and sliding distance. However, it is difficult to know the mutual relation of these factors. In this study, the friction characteristics using design of experiment containing 4 elements were investigated for an optimal condition for the best motorcycle break system employing regression analysis method. From this study, the result was shown that the applied load in frictional factors was the most important, next to sliding speed, number of ventilated disk hole.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.3
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• pp.221-230
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• 2020

In actual seawater desalination plant, the pressure loss due to frictional force of pipe is about 3~5 bar. Also, the pressure loss at pipe connection about 1~3 bar. Therefore, the total pressure loss in the pipe is expected to be about 4~8 bar, which translates into 0.111 to 0.222 kWh/㎥ of energy when converted into the Specific Energy Consumption(SEC). Reducing energy consumption is the most important factor in ensuring the economics of seawater desalination processes, but pressure loss in piping is often not considered in plant design. It is difficult to prevent pressure loss due to friction inside the pipe, but pressure loss at the pipe connection can be reduced by proper pipe design. In this study, seawater desalination plant piping analysis was performed using a commercial network program. The pressure loss and SEC for each case were calculated and compared by seawater desalination plant size.

• Tribology and Lubricants
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• v.18 no.4
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• pp.305-311
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• 2002

Three different kinds of brake discs including two coated brake discs and one steel disc were tested under the same experimental conditions on a reduced scale braking test bench. A braking test bench was specially designed to analyse thermo-mechanical and frictional behaviors of two types of brake with different sizes in stop and hold braking modes. Plasma spray coating technique was also used to coat the discs with ceramic powder. During the test four commercial brake pads were coupled with discs. Ceramic coated discs showed good stability in friction coefficient at high speed and high energy braking conditions. But they caused large wear loss of pad mass compared with the steel disc. It was shown that thermal barrier effect in ceramic coated discs adjusted the thermal partition between pad and disc. For a steel disc. it showed fluctuating friction coefficient at high speed but small wear loss of pad mass compared with ceramic coated discs.

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.3
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• pp.61-68
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• 2001

A linear motor has a lot of advantages in comparison with conventional feed mechanisms: high transitional speed, acceleration, high control performance and good positioning at high speed. Through the omission of a power transfer element, the linear motor shows no wear and no backlash, has along lifetime and is easy to assemble. Recently, the two types of linear motors, asynchronous and synchronous linear motors, are often applied to machine tools as a fast feed mechanism. In this paper, a comparison between the two types of linear motors as to power loss and thermal behavior is made. The heat sources of the linear motor-the electrical power loss in the motor and the frictional heat on the linear guidance-are measured and compared. Also, the temperature on the linear motor and machine structure is measured and presented.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.6
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• pp.115-122
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• 1999

A friction tester to measure friction force generated at the interface between the piston ring and the cylinder liner was developed. Modified piston ring is bar-shaped and 100mm long. Surface of the modified piston ring is machined by the profile grinding machine to be formed as a shape of an arc of a circle. Measured data are treated as mean effective friction force and power loss. From this test it can be confirmed that friction force is deeply affected by surface shape of the piston ring and viscosity of supplied oil. Friction force is deeply affected by surface shape of the piston ring and viscosity of supplied oil. Friction force is decreased and power loss is increased with increasing velocity. And it is known that region of mixed lubrication is broader than estimated with theoretical analysis. it is expected that this tester can be used as the optimization tool of the surface shape of the piston ring at the first stage of development of the piston rings.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.04a
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• pp.97-107
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• 1998

Three different kinds of brake discs including two coated brake discs and one steel disc were tested under the same experimental conditions on a reduced scale braking test bench. Braking test bench was specially designed to analyse thermo-mechanical and frictional behaviors of two sizes of brake discs in stop and hold braking modes. And Plasma spray coating technique was used to coat ceramic powder on the discs. In the test four commercial brake pads were coupled with discs. Ceramic coated discs had shown good stability in friction coefficient at high speed and high energy braking conditions. But they caused large pad mass wear loss compared with the steel disc. It was shown that thermal barrier effect in ceramic coated discs adjusted the thermal partition between pad and disc. For a steel disc, it had shown fluctuating friction coefficient at high speed but a fittie pad mass wear loss compared with ceramic coated discs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.14-21
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• 2017

The extreme floods recently are have been attributed global warming, The development of a canal tunnel to prevent floods by making a bypass or undercurrent to flood discharge in a major flooding area is required because urban flooding in heavy rainfall occurs frequently, increasing the impermeability according to lack of capacity in sewage to urbanization by the existing urban basin. In this study, a numerical simulation was performed to support design standards for a multi-purpose waterway tunnel combined road tunnel of canal tunnel. The numerical simulation showed that the size of the friction loss occurring in the tunnel section of the same channel occurred more than the theoretically calculated frictional loss derived from the numerical simulations. This is probably due to the additional frictional loss caused by the change in the flow structure due to the geometry of the pipe when the shape of the channel is non-circular. The increase in friction loss was more pronounced in the laminar flow than in the turbulent flow. Depending on the shape of the conduit, the friction loss should be adjusted for accurate flow calculations. This result can provide the basin information about the design of flood by a pass conduit.

• Tribology and Lubricants
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• v.23 no.4
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• pp.156-161
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• 2007

The friction test using disk-on-pad type was carried out and regression analysis with friction parameters was applied fur wear loss presumption of motorcycle break disk. The wear loss has an effect on the frictional factor such as applied load, sliding speed, and number of ventilated disk hole. However, it is difficult to know the mutual relation of these factors on wear loss of motorcycle break disk. From this study, the result was shown that the regression analysis equation containing 4 elements were constructed and this equation had a trust of 95% in wear loss presumption of motorcycle break disk. It is possible to apply for another automobile parts.

• Tribology and Lubricants
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• v.3 no.1
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• pp.39-46
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• 1987

Frictional loss in turbulent regime is abnormally increased compared with in laminar regime. Thus the consideration of temperature rise across fluid film is significant in analysis and conventional isothermal theory loses its usefulness for performance prediction. This paper proposes to the three-dimensional thermohydrodynamic analysis of finite journal bearings operating under turbulent condition using two-equation model($\kappa-\varepsilon$ model) proposed by Hassid & Poreh. The equations are solved numerically by finite difference method. We make the analysis applicable even at large eccentricity when back flow of the lubricants occurs and axial flow is no longer ignored compared to circumferential flow.