http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
한용운 嶺南大學校 工業技術硏究所 1982 연구보고 Vol.10 No.1
In a laminar boundary layer, the effects of the normal constant suction and blowing on the surfaces of the 2-dimensional circular cylinder were invertigated by solving the boundary layer equation in a shape of the series equation. The normal blowing and suction speeds were considered as the boundary conditions and both the speeds were 10% of the free stream velocities. The results of the computation show that for the case of the suction the separation point is delayed to 111.7°from 107.9°, the separation point of no boundary layer control, and the separation point of the blowing goes to 106.04°. But, the distribution of the suction shearing stress on the surface of the circular cylinder is not favourable comparing with that of blowing. Anyway, in the case of the suction, the delaying of the separation point offers the high performance of reducing the wake region.
韓龍雲,金重燁,權純益 嶺南大學校 工業技術硏究所 1981 연구보고 Vol.9 No.2
The factors that effect the power output of diesel engine are intake temperature, intake pressure, compression ratio and so on, in constant revolution. Intake pressure and compression ratio of them are much more effective. If the compression ratio is raised, the thermal efficiency of engine increases, but silent driving is difficult for maximum combustion pressure. The durability of engine decreases also for vibration and mechanical strain of materials, and the weight of engine per horse power increases. In this paper an intake pressure in charge of negative effects to lower compression ratio is raised. The compression ratio is decreased through the gasket is replaced by thick copper plate between cylinder and cylinder head. The effect of supercharge is evaluated experimentally from measuring of an engine power output, fuel consumption, and intake air volume. As a result of a decreased compression ratio, it becomes the same as natural aspiration before change compression ratio to increase about 3% to supercharging-pressure change ratio per unit compression ratio in mean effective pressure. And it becomes also the same as natural aspiration before change compression ratio to the increase of supercharging pressure about 1.8% in thermal efficiency. In case the supercharging pressure is much greater than the former to increase intake air pressure, it will give better effects to lower compression ratio than higher compression ratio with natural aspiration.
김동식,한용운,황은하 金烏工科大學校 1990 論文集 Vol.11 No.-
Axisymmetric jet flow, at the inital region, Was experimentally studied. The contraction was made by the Morel's Method and the experimental data was analyzed by statistical technique. In this study, mean velocity, and other turbulent quantities were measured by Hot-Wire Anemometer units and half velocity radius, potential core length, and jet spreading radius were calculated. Assumed by Gaussian distribution pattern, The divided two region's flow characters were matched by asymptotic equation and were modelled with exponential pattern in the intitial region.
Immersed Solid Method 를 이용한 외접형 기어 펌프의 수치해석
윤용한(Yong Han Yoon),박병호(Byung Ho Park),한용운(Yong Oun Han),홍병주(Byeong Joo Hong),심재술(Jaesool Shim) 대한기계학회 2014 大韓機械學會論文集B Vol.38 No.1
본 연구는 고속 회전형(~10,000 rpm) 기어펌프의 질량유량과 효율을 예측하기 위해서 2 차원 immersed solid method(ISM)를 이용한 수치해석을 수행하였다. 기어펌프와 하우징의 순환유동을 고려하기 위하여 유체 유동을 난류 유동으로 가정하였고, 기어 펌프의 입 출구의 일정 압력 조건하에 기어펌프의 회전 속도를 부가하였다. 기어펌프의 다양한 회전 속도 및 기어 끝 단과 하우징 사의의 서로 다른 간극에 대한 질량유량 및 효율을 검토하였다. 해석 결과로서, 회전 속도가 증가할수록 평균 질량유량 및 효율은 증가하였고, 기어펌프와 하우징의 간격이 증가할수록 평균 질량유량 및 효율은 감소하였다. 간격이 없는 조건하의 6,000 rpm, 8,000 rpm, 10,000 rpm 회전속도에의 효율은 각각 85.11 %, 90.94 %, 93.62 % 를 얻었고, 간격이 0 m, 0.00001 m, 0.00003 m 에 대해서 효율은 각각 93.62 %, 93.29 %, 92.74 % 를 얻었다. In this study, an ISM (immersed solid method) was used for investigating the mass flow rate and efficiency of an involute-gear pump featuring very high rotational speed. For considering circulation flow at the gear pump and housing, fluid flow was assumed as turbulent, and the rotational speed of the gear pump increased under the condition of constant pressure at both the inlet and outlet. The efficiency and mass flow rate of the gear pump were studied by varying its rotational speed and the clearance between the gear tip and the housing. In the simulation results, as the rotational speed were increased, the average mass flow rate and efficiency increased. Furthermore, as the clearance between the gear tip and the housing was increased, the average mass flow rate and efficiency decreased. The efficiency was 85.11, 90.94, and 93.62 at rotational speeds of 6,000 rpm, 8,000 rpm, and 10,000 rpm, respectively, under the condition that there was no clearance. In addition, the efficiency was 93.62, 93.29, and 92.74 at clearances of 0 m, 0.00001 m, and 0.00003 m respectively.
한용운(Yong Oun Han),김정현(Jung Hyun Kim),황인호(In Ho Hwang),서정복(Jung Bok Seo),임병훈(Byung Hoon Lim),정의헌(Ui Hyun Jung) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5
In order to investigate the vortex body frame interaction around the side mirror of a passenger car velocity vector fields in the wake, pressure distributions and boundary layer flows over both the mirror surface and the mirror housing, have been measured by several experimental tools. It was resulted that only within an half downstream distance of the mirror span there appears the recirculation zone, and also found that vortex trail towards to the driver side window between A and B pillars, making the acoustic noise and vibration. Wake vortex rolls up after this recirculating zone and makes the trail of the vortex center towards the driver side window, which was also confirmed by measurements of wake velocity vectors in the vertical sections of the trail and visualization over the side mirror surfaces as well. It was also observed that total pressure distribution over the mirror surface has the minimum peak near the lower tip region which can be considered as the origin of the vortex center. It can be concluded that the geometrical modification of the lower tip and the upper root area of the mirror housing is the key to control the wake vortex.