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MRF 기법을 적용한 림 구동 프로펠러의 반류중 성능 예측
박정훈(Jeong-Hoon Park),최재엽(Jae-Yeop Choi),이창민(Chang-Min Lee) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.11
This study presents PBW(Propeller Back Water) performance of rim driven propeller based on Ka4-70 propeller and nozzle No.19A duct. Rim driven propeller is operated by magnetic force between stator in duct and rotor on propeller blade tip. So it has many advantages relative to conventional shaft driven propeller, for example, saving space and weight, low noise, high reliability, etc. But propulsion efficiency can be reduced because rim and rotor on blade tip makes additional drag and moment. In this paper, we investigated hydrodynamic performances and efficiency of rim driven propeller attached to 21 inches UUV, and compared those to results of conventional propeller. To shorten calculation time, MRF(Moving Reference Frame) method was adopted and steady simulations were carried out by using commercial CFD software.
림 구동 일체형 추진장치의 유체역학적 특성에 관한 수치적 연구
정성문(Seongmun Jung),박정훈(Jeong-Hoon Park),최재엽(Jae-Yeop Choi),하성준(Sung-Jun Ha),권오준(Oh Joon Kwon) 한국전산유체공학회 2019 한국전산유체공학회지 Vol.24 No.1
In this paper, the hydrodynamic characteristics of a rim driven integrated thruster was numerically investigated. To consider the effect of cavitation phenomenon, multi-phase flow model and homogeneous mixture model were applied to the three dimensional incompressible RANS equations. To validate the numerical methods and the models adopted to the present study, the propeller P4381 was numerically analyzed and the numerical results and experimental one reached good agreement. The rim driven integrated thruster applied to the unmanned underwater vehicle at the water depth of 5m was numerically solved for various advance ratios. The flow field of the conventional thruster that has gap between the tip of the propeller and inner wall of the duct was also numerically solve and the results were compared to the results of the rim driven integrated thruster. As a result, it was revealed that both the rim driven integrated thruster and conventional thruster suffer from the cavitation phenomenon on the suction side of the propeller and the stator. It was also found that the difference of the thrust generated by the rim driven integrated thruster and conventional thruster is not significant whereas the difference of the torque could not be neglected. Finally, it was observed that the thrust and torque by thruster in the multi-phase flow was estimated to be smaller than those of single-phase flow.
별도의 고정타를 갖는 수중운동체 승강타의 제어력에 미치는 받음각의 영향에 대한 실험적 연구
박정훈(CJeong-Hoon Park),신명섭(Myung-Sub Shin),최재엽(Jae-Yeop Choi),황종현(Jong-Hyun Hwang),신영훈(Young-Hun Shin),김연규(Yeon-Gyu Kim) 한국해양공학회 2016 韓國海洋工學會誌 Vol.30 No.4
Conventionally, the static angle of attack and static elevator tests are carried out separately to estimate hydrodynamic stability derivatives of underwater vehicles. However, it is difficult to verify the interaction between the angle of attack and elevator angle in such cases. In this study, we perform a static elevator with angle of attack test where both the angle of attack and elevator angle are varied simultaneously. The experimental results show that the angle of attack has an influence on the elevator control force and that this tendency is dependent on the sense in which the angle of attack and elevator angle are varied. We predict level flight performance using hydrodynamic derivatives estimated through this experiment. The predictions considering the effect of angle of attack show good agreement with trials conducted in the open sea.