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Numerical simulation of three-dimensional external gear pump using immersed solid method
Yoon, Yonghan,Park, Byung-Ho,Shim, Jaesool,Han, Yong-Oun,Hong, Byeong-Joo,Yun, Song-Hyun Elsevier 2017 Applied thermal engineering Vol.118 No.-
<P><B>Abstract</B></P> <P>External gear pumps are typically used as positive displacement machines that are capable of developing high pressures while operating at low suction pressures in hydraulic systems. Considerable attention has paid recently been given to investigating the flow characteristics and enhancing pump efficiency using theoretical, numerical, and experimental approaches. In this study, three-dimensional (3D) numerical simulations of an external gear pump were conducted to study the effects of 3D geometrical design parameters on pump performance characteristics such as the flow rate. The characteristics of internal flow are also presented with respect to the internal pressure peak, local cavitation, and delivery pressure ripple. The immersed solid method (ISM) was used to simulate the operation of a gear pump under extreme conditions of high rotational speed. We found that the maximum flow rate of the gear pump is a strong function of the gear tip clearance and lateral clearance. Using the 3D model, the effect of the lateral clearance on flow rate is highlighted.</P>
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.
윤용한(Yong Han Yoon),소범식(Bum Sik So),조정호(Jung Ho Cho),엄영철(Young Chul Eom),심재술(Jaesool Shim) 대한기계학회 2019 大韓機械學會論文集B Vol.43 No.7
본 연구에서는 두 개의 외장패널이 맞닿는 부분에 형상을 가진 기계적 체결이 가능한 진공단열 외장패널의 3가지 CASE 열전달 해석을 수행하였다. 체결부의 열교부위 선형 열관류율 값을 계산하였으며, 열교를 비교함으로써 단열측면에서 우위의 설계안을 도출하였다. 열전달해석 분석결과, 열교부위의 길이가 0.039m, 0.083m, 0.1656m으로 약 2배씩 선형적으로 증가 했을 때, 열교부위의 선형 열관류율 값은 각각 0.0476W/m·K, 0.2113W/m·K, 0.2663W/m·K으로 열교부위 길이에 비례하여 선형적으로 증가하지 않음을 확인하였다. 2차원 열전달해석을 통해 얻은 데이터를 ISO 10211 기준에서 제시하는 계산식에 대입하여 선형 열관류율 값을 산출하였다. 3가지 CASE의 체결부 열교부위 선형 열관류율 값을 계산하여 비교한 결과, CASE 1 패널이 선형 열관류율 값이 가장 작아 열교 측면에서 가장 우수한 설계임을 확인하였다. In this study, a heat transfer simulation of three types of vacuum insulation panels that can be mechanically fastened with two external panels was conducted. The linear thermal transmittance of the thermal bridge was calculated and the design of superiority in terms of insulation was derived. Results of heat transfer analysis indicated that when the length of the thermal bridge was linearly increased by two times to 0.039, 0.083, and 0.1656 m, the linear thermal transmittance of the thermal bridge was 0.0476, 0.2113, and 0.2663 W/m·K, respectively. In addition, the linear thermal transmittance did not increase linearly in proportion to the length. The linear thermal transmittance was calculated by substituting the data obtained from the two-dimensional heat transfer analysis into the formula given in the ISO 10211 standard. A comparison of the values of the linear thermal transmittance of the joints of the three cases verified that Case 1 had the best thermal bridge design because it exhibited the smallest linear thermal transmittance.