• Journal of Advanced Marine Engineering and Technology
• /
• 제25권4호
• /
• pp.846-856
• /
• 2001

An experimental study has been made to investigate the effect on wake flow and vortex shedding frequency by vortex stabilizer in Karman vortex type air flow sensor. The conditions investigated include 3 types of shapes and 3 types of separation distances of the vortex stabilizer. The phase averaged technique and smoke-wire flow visualization method are used to understand the detail information. The rolling up position of shear layer is fixed by the influence of the vortex stabilizer. Especially, the convex type vortex stabilizer has shown the more stable repeatability and linearity regarding the vortex shedding frequency compared to the other types.

• 동력기계공학회지
• /
• 제9권3호
• /
• pp.33-38
• /
• 2005

The aerodynamic performance of a cross-flow fan is strongly influenced by the various design factors of a rear-guider and a stabilizer. The purpose of this paper is to investigate the effects of a rear-guider and a stabilizer on the aerodynamic performance of a cross-flow fan. The design factors considered in this paper are a rear-guider clearance, a stabilizer clearance, and a stabilizer setup angle, respectively. This experiment was carried out with a constant revolution number of 700 rpm in a cross-flow fan installed in the fan tester. The static pressure, flowrate, torque, and revolution number were measured in this paper. Also, the pressure coefficient and the efficiency were analysed according to the various assembly conditions using a stabilizer setup angle, a stabilizer clearance, and a rear-guider clearance in the indoor room air-conditioner.

• 동력기계공학회지
• /
• 제9권3호
• /
• pp.44-49
• /
• 2005

The aerodynamic performance of an indoor room air-conditioner using a cross-flow fan is strongly influenced by the various design factors of a rear-guider and a stabilizer. The purpose of this study is to investigate the effects of a rear-guider and a stabilizer on the aerodynamic performance in the maximum flowrate range of a cross-flow fan. The design factors considered in this study are a rear-guider clearance, a stabilizer cutoff clearance, and a stabilizer setup angle, respectively. Aerodynamic performances including maximum flowrate and power show the biggest magnitude distribution in the case of $45^{\circ}$, the stabilizer setup angle as well as nearly similar magnitude distribution regardless of the stabilizer cutoff clearances. Moreover, the more a rear-guider clearance increases, the more the magnitude of maximum flowrate and power increases.

• 동력기계공학회지
• /
• 제9권3호
• /
• pp.50-57
• /
• 2005

A cross-flow fan is strongly influenced by the various design factors of a rear-guider and a stabilizer. The purpose of this paper is to investigate the effects of a rear-guider and a stabilizer on the surface pressure of a rear-guider in an indoor room air-conditioner using a cross-flow fan. The design factors considered in this paper are a rear-guider clearance, a stabilizer clearance, and a stabilizer setup angle, respectively. The operating condition of a cross-flow fan was controlled by changing the static pressure and flowrate using a fan tester. All surface pressures of a rear-guider are differently distributed according to the stabilizer setup angle, and show a zero value in the flow coefficient, ${\Phi}{\fallingdotseq}0.5$ only of a stabilizer setup angle, $45^{\circ}$. Especially, they show a big negative value in the expansion angle larger than $34^{\circ}$ regardless of a rear-guider clearance, a stabilizer clearance, and a stabilizer setup angle. On the other hand, surface pressures for various stabilizer cutoff clearances are better than those for various rear-guider clearances.

• 한국군사과학기술학회지
• /
• 제4권1호
• /
• pp.137-146
• /
• 2001

According to the advanced development of Light Weight Torpedo, the overall items related with the parachute type and gore layout and air stabilizer of the parachute for fixed and rotary wing aircraft are described in this paper. Also, the drag-area which should satisfy the firing envelope, parachute inflation characteristics, stability of parachute and torpedo in airdropping, water entry impact on torpedo and parachute constituted the principle design factors. The important trial and errors occurred in the step of performance of the parachute for fixed and rotary wing aircraft are investigated and analyzed.

• 소음진동
• /
• 제8권5호
• /
• pp.870-878
• /
• 1998

The cross-flow fan which constitutes a fan-duct system with a stabilizer and a scroll casing is widely used in many air-ventilating and air-conditioning devices. Its ooperating points of high efficiency and loading conditions frequently induce a annoying sharp tonal component of discrete frequency on the noise spectrum, which is open called as a BPF(Blade-Passing-Frequency) noise and degrades the sound quality of the devices. this BPF tone has been one of the defects of the cross-flow fan. This study proposes two methods in order to reduce this tonal noise component, which are the random distributions of the fan blades and the skewed shapes of the stabilizer. The proposed methods are verified by a simple analytical model and are applied in manufacturing the cross-flow fan and the stabilizer samples. Some experiments are carried out to verify the reduction capability of BPF tones of above two schemes and the experimental results are analyzed. The comparison between two method is also carried out.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 1995년도 제2회 KOSCI Workshop
• /
• pp.105-121
• /
• 1995

The objective of this study is to find out the design data for gas burner with an axal and radial type nozzles. The design parameters are chosen as the stabilizer type, the jet hole size of gas nozzle, the distance between gas nozzle and stabilizer, the size of stabilizer and the hole size of stabilizer, the stabilizer type with or without air swirler, the angle of swirler. For the experimental test combustor sizing ${\phi}1.3m{\times}L4.5m$ is designed and manufactured, in which the set up of power diagram, the exhaust gas analysis, blow-off test, the flame temperature and the direct photography are performed.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 1995년도 추계학술대회논문집; 한국종합전시장, 24 Nov. 1995
• /
• pp.136-141
• /
• 1995

Room Air Conditioner(이하 RAC) 실내기는 열교환기, Cross Flow Fan(이하 CFF), 곡률, Stabilizer(이하 STB) 등 여러 설계인자가 소음, 풍량 및 압력 등에 상호 복합적으로 연성(Coupled)되어 있어 각 인자가 성능에 미치는 영향을 정량적으로 밝혀 내기가 쉽지 않다. 따라서 RAC 실내기의 고성능 및 저소음화를 실현하기 위해서는 실내기를 구성하는 각 인자간의 상호 관련성 및 각 인자가 소음.성능 등에 미치는 영향을 체계적으로 분석하는 것이 필수적이다. 본 연구에서는 설계인자중 소음 및 풍량에 민감한 영향을 주는 STB 위치 및 형상 등에 관하여 자세히 다루고자 한다. STB위치의 적절한 범위를 설정하기 위해 Laser Doppler Velicitimeter(이하 LDV)를 이용하여 곡률별 실내기 내부의 유속분포 및 속도 벡터를 측정하였고, CFF내부 Vortex의 정확한 위치를 찾아냈다. 또한 실내기 저소음화를 위한 소음원 규명 측면에서 실내기 내부의 난류도와 관련하여 속도 Fluctuation을 정의하고, 실험을 통해 구하였다.

• 동력기계공학회지
• /
• 제17권3호
• /
• pp.35-43
• /
• 2013

Generally, the chassis of an indoor RAC is composed of a rear-guider and a stabilizer. The aerodynamic performance of a cross-flow fan is strongly influenced by the various design factors of the chassis of an indoor RAC. The purpose of this paper is to select the optimum design factors through the aerodynamic performance of a cross-flow fan. The design factors are the leading angle of a rear-guider (${\theta}_1$), a stabilizer setup angle(${\theta}_2$), a rear-guider clearance(${\epsilon}_1$), and a stabilizer clearance(${\epsilon}_2$), respectively. As a result, the optimum design factors of an indoor RAC can be presented as a combination of ${\theta}_1=33^{\circ}$, ${\theta}_2=55^{\circ}$, ${\epsilon}_1=6{\sim}8mm$, and ${\epsilon}_2=7mm$ through the analysis of a static pressure coefficient and a static pressure efficiency.

• 동력기계공학회지
• /
• 제17권4호
• /
• pp.36-44
• /
• 2013

The aerodynamic performance of a cross-flow fan is strongly influenced by the various design factors of a rear-guider and a stabilizer. The design factors considered in this paper are a rear-guider clearance, a stabilizer clearance, and a stabilizer setup angle, respectively. Also, these factors are given to the various diameter ratio between a basic circle and a impeller. The static pressure and the flowrate of a cross-flow fan were measured with a fan-tester. It could be found that the useful design factors with a good aerodynamic performance exist in the certain assembly conditions of an indoor RAC. Therefore, it could be known that a new published patent determining the easy design of an indoor RAC can be applied in a variety of goods.