• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.2
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• pp.129-134
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• 2010

A diesel engine is equipped with a turbocharger for providing more power at a low engine speed region by supplying charge air to combustion chambers. The turbocharger makes it possible to satisfy stringent emission regulations and customers' demand of enjoying the fun to drive by increasing engine performance. However, the turbocharger has the disadvantage of making BPF(Blade Passing Frequency), hissing, surge, whistle, and blow noises. Among them, reducing the blow noise, a narrow-band noise(a general range : 1800~2000Hz), is possible by using a resonator that controls the narrow frequency band governing the resonance in the intake system. In this study, the optimum location of the resonator is found by employing Boost as a CAE(Computer Aided Engineering) tool and is confirmed by experiments of an engine dynamo test and a real vehicle test.

• International Journal of Highway Engineering
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• v.13 no.1
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• pp.223-228
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• 2011

The initial joint width design of the terminal joint between post-tensioned concrete pavement (PTCP) and jointed concrete pavement (JCP) was studied in this research. The joint width between PTCP and JCP directly affects noise and ride quality. If the initial joint width is very large, noise increases and ride quality decreases. If the initial joint width is very small, on the other hand, under high temperatures, PTCP slabs can blow up, or failures near the joint can occur due to excessive compressive stresses. The terminal joint width behavior between PTCP and JCP near Jumunjin at Donghae expressway under temperature changes was measured in August and November 2010 and the data was analyzed. From this study, the design methodology of the optimal initial terminal joint width was proposed.

• International Journal of Highway Engineering
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• v.12 no.3
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• pp.147-154
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• 2010

In post-tensioned concrete pavement(PTCP), one of the most important design variables is the initial joint width, in addition to the tensioning spacing. The joint width between PTCP slabs directly affects noise and ride quality. If the joint width is too wide, noise increases and ride quality decreases. If the initial joint width is too narrow, on the other hand, under high temperature, PTCP slabs can blow up, or failures near the joint can occur due to excessive compressive stresses. This study was conducted to determine the optimal initial joint width of PTCP and to investigate the joint width behavior under temperature changes. The experiments were performed using one-year-old PTCP slabs. The concrete temperatures were measured using the temperature measurement sensors installed at various depths. The joint widths were measured using vernier-calipers at different times of a day and the relationship between the joint width and temperature was analyzed. From this study, the design methodology to determine the optimal initial joint width of PTCP could be proposed.