• 대한설비공학회지:설비저널
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• 제30권5호
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• pp.51-55
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• 2001

일본의 도시바는 세계 최초로 독자적인 나선형 압축기구의 채용으로 밸브 없이 연속적인 압축이 가능한 헬리컬 압축기를 개발하였다. 이 압축기는 저소음, 저진동, 우수한 에너지 절약성, 콤펙트한 구조가 특징이다. 여기서는 상품개발 배경과 헬리컬 압축기의 구조, 특징등을 소개하고자 한다.

• 드라이브 ㆍ 컨트롤
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• 제12권4호
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• pp.1-7
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• 2015

In this study, a spiral valve which is used with a cryogenic linear expander and composed of plural plate coil shapes was examined. Generally, a spiral valve is well known for having excellent efficiency and low noise characteristics. In order to determine the movement characteristics and to investigate the limit of valve displacement, the stress variations according to the changes of operating pressure, displacement and workable temperature are discussed. From this examination, it is considered that the results of this study will significantly facilitate the design and development of a spiral valve for the cryogenic linear expander.

• Journal of Advanced Marine Engineering and Technology
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• 제24권5호
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• pp.86-96
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• 2000

This study is to consider that the helical intake port flow and fuel injection system have effects on the characteristics of engine performance and emissions in a turbocharged DI diesel engine of the displacement 9.4L. The swirl ratio for ports was modified by hand-working and measured by impulse torque swirl meter, For the effects on performance and emission, the brake torque, BSFC were measured by engine dynamometer and NOx, smoke were by gas analyzer and smoke meter. As a result of steady flow test, when the valve eccentricity ratio are closed to cylinder wall, the flow coefficient and swirl intensity are increased, And as the swirl is increased, the mean flow coefficient is decreasing, whereas the gulf factor is increasing. Also, through engine test its can be expected to meet performance and emission by the following applied parameter; the swirl ratio is 2.43, injection timing is BTDC $13^{\circ}$CA and compression is 15.5.

• 대한기계학회논문집B
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• 제33권1호
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• pp.9-16
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• 2009

This paper is the second of 2 companion papers which investigate in-cylinder swirl generation characteristics in helical port engine with wide valve angle. Two wide valve-angle engines, which are same ones and have slightly different rig swirl number, were used to compare the characteristics of cylinder-flow. One intake port is deactivated to induce swirl flow. A PIV (Particle Image Velocimetry) was applied to measure in-cylinder velocity field during intake stroke. The results show that the intake flow component passing through valve area near the cylinder wall is not negligible in helical port engine with wide valve angle contrary to conventional one. The effect of this velocity component on in-cylinder increases as the swirl ratio rises and compression process progresses. Consequently, this component destroys in-cylinder swirl flow completely during compression resulting in no actual swirl at the end stage of compression.

• 대한기계학회논문집B
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• 제32권10호
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• pp.761-768
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• 2008

This paper is the first of 2 companion papers which investigate in-cylinder swirl generation characteristics in helical port engine with wide valve angle. Two wide valve-angle engines, which are same ones and have slightly different rig swirl number, were used to compare the characteristics of cylinder-flow. One intake port is deactivated to induce swirl flow. A PIV (Particle Image Velocimetry) was applied to measure in-cylinder velocity field during intake stroke. The results show that the intake flow component passing through valve area near the cylinder wall is not negligible in helical port engine with wide valve angle contrary to conventional one. The effect of this velocity component on in-cylinder increases as the swirl ratio rises and intake process progresses. Consequently, this component interferes the formation of in-cylinder swirl flow resulting in lower actual swirl.

• 대한기계학회논문집B
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• 제40권7호
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• pp.417-427
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• 2016

본 논문은 반 쐐기형 연소실에서 포트 형상에 따른 정상유동 특성을 비교한 연구의 첫 번째로 통상적인 충격식 스월측정기 평가위치인 1.75B에서 입자영상유속계로 반 쐐기형 연소실에 직선형 포트와 나선형 포트를 적용하여 평면유속을 측정하고 비교하였다. 속도분포 분석 결과 직선형 포트에서는 밸브리프트 4 mm 이하, 그리고 나선형 포트에서는 2 mm 이하에서 두 개의 스월이 형성되고 이후 리프트가 증가하면 하나의 스월만 관찰된다. 리프트에 따른 유동체계의 천이점이 포트형상에 따라 상이하여 직선형 포트에서는 리프트 4 mm와 5mm를 경계로 유동 특성이 완전히 바뀌는 반면, 나선형 포트에서는 리프트 증가에 따라 점진적 변화만 관찰된다. 또한 모든 포트에서 1.75B 위치에서 편심도는 측정값이 왜곡되지 않는 범위에 들어오지 않고, 특히 직선형 포트의 편심도가 매우 크다. 동시에 포트형상에 관계없이 ISM 평가와 상응하는 실린더 중심 기준의 평균접선속도는 ISM 평가에서 가정한 속도보다 매우 낮고, 속도분포 특성도 ISM 평가의 가정과 매우 다르다.

• 한국자동차공학회논문집
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• 제5권5호
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• pp.157-169
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• 1997

The effects of intake port eccentricity on the characteristics of in-cylinder swirl ratio in a 4-valve diesel engine having the two intake ports; one is a helical intake port and the other is a tangential intake port were investigated by using the ISM(impulse swirl meter) in steady flow test rig. Swirl ratio($R_s$) and mean flow coefficient($C_{f(mean)}$) with valve eccentricity ratio($N_y$) and axial distance(Z/B) were measured. As the results from this experiment, the characteristics of in-cylinder swirl ratio formed by a 4-valve cylinder head were largely affected by intake port eccentricity. There is a difference in the mass flowrate through the two intake ports, and the mass flowrate through the tangential intake port is 19% more than that of the helical intake port. Therefore, we could know that the effects of the mass flowrate ratio through each intake port besides intake port shape should be conidered.

• 대한기계학회논문집B
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• 제21권6호
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• pp.793-803
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• 1997

This experimental study was mainly investigated on the swirl flow characteristics in the cylinder generated by a helical intake port. LDA system was used for the measurement of in-cylinder velocity fields. Tangential and axial velocity profiles, with varying valve lifts, valve eccentricity ratios and axial distance, were measured. When the intake valve was set in the cylinder center, we could find that in-cylinder swirl flow fields were composed of a forced vortex motion and a free vortex motion in the vicinity of the cylinder center and the cylinder wall respectively. In case of valve eccentricity ratio, N$_{y}$ = 0.45, the vortex flow which rotates to the opposite direction of a main rotating flow in the cylinder was found. And the reverse flow toward the cylinder head surface was also found in axial velocity profile and it showed the tendency of the linear decrease in the region of 0.leq.Y/B.leq.1.2.2.

• 대한기계학회논문집B
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• 제21권6호
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• pp.725-734
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• 1997

The effect of helical intake port geometry on in-cylinder swirl flow characteristics was studied. Two helical intake ports were selected to change swirl ratio, mean flow coefficient with the variation of valve lifts, valve eccentricity ratios and axial distance. The measurements were made by using an impulse swirl meter. The port B modified to increase the swirl ratio( $R_{s}$) had the tendency of the increased non-dimensional rig swirl ( $N_{r}$) distribution in comparison with that of the port A. And the $N_{r}$ distribution was remarkably improved at low valve lifts. The modification of the geometry to increase the swirl ratio ( $R_{s}$) in helical intake port resulted in the decrease of the mean flow coefficient ( $C_{f(mean)}$) regardless of valve eccentricity ratio ( $N_{y}$). And also non-dimensional rig swirl ( $N_{r}$) in the high valve lift affected the calculation of swirl ratio considerably.onsiderably.