• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.389-392
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• 2008

The thrust axis alignment of the launch vehicle is very important because of the misalignment causes the unstable attitude control and results in mission failure. Generally, optical methods such as digital theodolite and laser tracker and mechanical method such as turn table method are used to thrust axis alignment. This article deals with the simple method of thrust axis alignment of Kick Motor.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권11호
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• pp.564-571
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• 2006

In this paper, the estimation of Z-axis thrust ripple and vibration of BLDC motor with asymmetrical permanent magnet overhang is performed by 3-D Finite Element Method (3-D FEM) and vibration experimentation. The ripple of Z-axis thrust is due to armature reaction field in BLDC motor driven to squire wave. That is generating to Z-axis vibration. The analysis results of Z-axis thrust and the vibration by Z-axis thrust ripple is validated by comparison with experimental result.

• 항공우주기술
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• 제9권2호
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• pp.138-142
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• 2010

발사체의 기체 축과 추력 축이 요구 조건에 맞게 정렬되지 않을 경우엔 자세 제어 오차가 허용 범위를 초과할 수 있으며, 심각할 경우 미션 실패로 이어질 수 있다. 일반적인 발사체의 추력 축 정렬에는 데오도라이트와 레이져 트레커를 사용하는 광학적 방법과 턴테이블을 이용하는 기계적 방법이 사용된다. 본 논문에서는 3차원 측정 결과로부터 획득된 형상 정보에 기반하여 경사도계를 사용하는 킥모터 시스템의 추력 축 정렬 방법에 대해서 다룬다.

• 한국추진공학회지
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• 제15권1호
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• pp.76-82
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• 2011

우주발사체의 추력 축 정렬이 제대로 안되면 발사체의 자세제어가 불안정해지고 심할 경우 임무 실패를 초래 할 수 있으므로 추력 축 정렬은 매우 중요하다. 일반적으로 추력 축 정렬은 데오돌라이트나레이져 트렉커와 같은 광학 방식을 사용하거나 턴테이블을 사용하는 기계식 방식을 사용한다. 본 연구에는 중력 방향과 관련된 경사도계를 이용하는 쉬운 방법을 다룬다. 경사도계는 지구 중력방향과 수직이 되면 0도를 가리킨다. 이 방법은 두 개의 경사도계가 필요한데, 하나는 기준이고 다른 하나는 정렬용이다. 두 경사도계의 각도차이는 TVC 구동기를 조정하는 참고치가 된다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권7호
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• pp.346-352
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• 2006

In Brushless DC Motor, there are Permanent Magnets (PMs) with driving circuit and sensor for detecting to rotor position and rotation speed. In the case of using hall IC sensor which response to magnetic flux, that is required to additional sensor magnet for rotor position detecting. Most of BLDC motor, However, take asymmetrical overhang of PM in rotor instead of additional sensor magnet for operating of hall IC sensor. The asymmetrical overhang of PM occur rotor thrust to z-axis direction that is lead to not only damage of bearing but also intensive noise and vibration. Therefore, the analysis of magnet overhang effect in the side of vibration and drive to hall If sensor is required to precise. In this paper, 2-D Finite Element Method is used to solve precise field computation and thrust of z-axis direction considering asymmetrical magnet overhang. And also the z-axis thrust from the analysis result is compared to experimental result. In conclusion, the purpose of this paper minimize to noise and vibration of BLDC Motor as analyzes to asymmetrical magnet overhang effect.

• Journal of Advanced Marine Engineering and Technology
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• 제30권1호
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• pp.150-156
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• 2006

A Flapping foil Produces an effective angle of attack, resulting in a normal force vector with thrust and lift components, and it can be expected to be a new highly effective propulsion system. A heaving foil model was made and it was operated within a circulating water channel at low Reynolds numbers. The unsteady thrust and lift acting on the heaving foil were measured simultaneously using a 6-axis force sensor based on force and moment detectors. We have been examined various conditions such as heaving frequency and amplitude in NACA 0010 Profile. The results showed that thrust coefficient and efficiency increased with reduced frequency and amplitude. We also Presented the experimental results on the unsteady fluid forces of a heaving foil at various Parameters.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.222-227
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• 2005

A Flapping foil produces an effective angle of attack, resulting in a normal force vector with thrust and lift components, and it can be expected to be a new highly effective propulsion system. A heaving foil model was made and it was operated within a circulating water channel at low Reynolds numbers. The unsteady thrust and lift acting on the heaving foil were measured simultaneously using a 6-axis force sensor based on force and moment detectors. We have been examined various conditions such as heaving frequency and amplitude in NACA 0010 profile. The results showed that thrust coefficient and efficiency increased with reduced frequency and amplitude. We also presented the experimental results on the unsteady fluid forces of a heaving foil at various parameters.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.45-49
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• 1998

In this paper, the direct thrust control of PWM Inverter-fed Single-sided Linear Induction Motor (hereinafter referred to as "SLIM") is achieved with Space Vector control and PI control. The trembling of air gap length which is occured between the primary winding core and the secondaty structure of the SLIM must be minimized in order to get quick response characteristic. First, voltage equations of SLIM are shown on the suitable d-q axis equivalent circuits which analyze characteristics of the thrust and the normal force. Also, modeling and analysis of the d-q axis equivalent circuits are able to make robust transient thrust from the current regulation in the equivalent circuits. These results exemplified the direct drive of SLIM with the reference speed and thrust were verified by the experiments.periments.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권8호
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• pp.463-468
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• 2004

This paper was applied space harmonic method as a characteristic analysis technique for slotless PMLSM. There is advantages of active response to the change of design parameters as well as reduction of the calculation time. The method can be overcome disadvantages of finite element analysis that needs long times calculation, repetitions of pre and post-process. In this paper, 3D-space harmonic method was applied to consider the precise description of end turn coil shape and the changes of characteristic according to changes of length of z-axis direction. The thrust of optimal design was performed using genetic algorithm to enhance the thrust which is the disadvantage of slotless type PMLSM. For design parameters, width of permanent magnet, width of coil, width of coil inner and lengths of z-axis direction were selected. For objective functions. thrust per weight. thrust per volume. multi-objective function was selected.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.1108-1111
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• 2017

무기체계 운용 방식으로 인해 추진기관의 노즐이 축방향과 일정한 각도를 갖게 될 경우 노즐 출구 형상이 전체 외형의 형상에 부합되도록 설계하기 위해서 절삭을 하게 되는 경우가 발생하게 된다. 이러한 절삭 노즐의 경우 비절삭 노즐에 비해 필연적으로 추력 손실이 발생하게 된다. 설계 단계에서 이러한 추력 손실을 모사하기 위해서는 유동해석을 통한 계산이 필요하며, 해석을 통해 계산한 추력 손실을 검증하기 위해 연소시험을 수행하였다. 절삭 노즐과 비절삭 노즐을 비교시험한 결과 유동해석을 통해 계산한 추력 손실은 약 16.6%이며 시험에서 도출된 추력 손실은 약 15.0%로 나타남을 확인하였다.