• Title/Summary/Keyword: Velocity Distribution

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Velocity and Friction Force Distribution in Rotary CMP Equipment (회전형 CMP장비의 속도 및 마찰력 분포 해석)

  • Kim, Hyeong Jae;Jeong, Hae Do;Lee, Eung Suk;Sin, Yeong Jae
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.5
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    • pp.39-39
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    • 2003
  • As the design rules in semiconductor manufacturing process become more and more stringent, the higher degree of planarization of device surface is required for a following lithography process. Also, it is great challenge for chemical mechanical polishing to achieve global planarization of 12” wafer or beyond. To meet such requirements, it is essential to understand the CMP equipment and process itself. In this paper, authors suggest the velocity distribution on the wafer, direction of friction force and the uniformity of velocity distribution of conventional rotary CMP equipment in an analytical method for an intuitive understanding of variation of kinematic variables. To this end, a novel dimensionless variable defined as “kinematic number” is derived. Also, it is shown that the kinematic number could consistently express the velocity distribution and other kinematic characteristics of rotary CMP equipment.

Velocity and Friction Force Distribution in Rotary CMP Equipment (회전형 CMP장비의 속도 및 마찰력 분포 해석)

  • 김형재;정해도;이응숙;신영재
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.5
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    • pp.29-38
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    • 2003
  • As the design rules in semiconductor manufacturing process become more and more stringent, the higher degree of planarization of device surface is required for a following lithography process. Also, it is great challenge for chemical mechanical polishing to achieve global planarization of 12” wafer or beyond. To meet such requirements, it is essential to understand the CMP equipment and process itself. In this paper, authors suggest the velocity distribution on the wafer, direction of friction force and the uniformity of velocity distribution of conventional rotary CMP equipment in an analytical method for an intuitive understanding of variation of kinematic variables. To this end, a novel dimensionless variable defined as “kinematic number” is derived. Also, it is shown that the kinematic number could consistently express the velocity distribution and other kinematic characteristics of rotary CMP equipment.

Measurements of Velocity Distribution Function in Circular Open Channel Flows by Stereoscopic PIV (3차원 PIV에 의한 원형 개수로 유동의 속도분포 함수 측정)

  • Yoon, Ji-In;Sung, Jae-Yong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.5
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    • pp.365-374
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    • 2011
  • For the first time, the present study has measured the velocity distribution function in circular open channel flow in a three-dimensional shape using a stereoscopic PIV system. For a given channel slope, water depth was varied from 30% to 80% of the channel diameter. Then, the characteristics of the velocity distribution function was compared according to the change of the water depth. Unlike a rectangular channel, the present experiment exhibited quite different shapes in the velocity distribution function whether the water depth is higher than 50% or not. Especially, the position of maximum velocity in the central and side wall changes in a different manner for the water depth above 50%. By differentiating the velocity distribution function, local wall friction coefficient was evaluated as a function of wall position. If the water depth goes down, the difference between the maximum and minimum values in the local wall friction coefficient increases, and the averaged value a1so increases.

A Study on Flow Characteristics of a Ginseng Cleaner Using PIV (PIV에 의한 인삼세척기의 특성연구)

  • 송치성
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2000.05a
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    • pp.140-145
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    • 2000
  • The objective of experimental study is to apply simultaneous measurement by PIV(Particle Image Velocimetry) to high_speed flow characteristics within ginseng cleaner model. Three different kinds of flow rate(15.20 27ℓ/min) are selected as experimental condition. Optimized cross correlation identification to obtain velocity vectors is implemented by direct calculation of correlation coefficients. The instantaneous velocity distribution time0mean velocity distribution and velocity profile are represented quantitatively for the deeper understanding of the flow characteristics in a ginseng cleaner model.

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Estimation of the Pipe Thickness using the Variation of the Group Velocity (군속도 변화를 이용한 배관 두께 측정)

  • Han, Seung-Hee;Hwang, Jong-Myung;Lee, Jang-Myung
    • The Journal of Korea Robotics Society
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    • v.5 no.1
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    • pp.32-40
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    • 2010
  • This paper proposes the technique of estimating the pipe thickness using the measured group velocity. To measure the group velocity from the accelerometer data in the frequency domain, Wigner-Ville distribution is utilized, which interprets the waveform of the shock wave. Using this measured group velocity, this paper proposes the technique to estimate the thickness of pipes with the impact on the pipe. The group velocity is estimated by the modeling correlation between the group velocity and the thickness of the pipe based on the propagation velocities. The correlation model between thickness and group velocity has been proved through the real experiments. The measured group velocity in the frequency-domain is the maximum at the center frequency of the bending waves in the modeling of the group velocity. In addition to these, a smoothing technique for analyzing lamb wave Wigner-Ville distribution has been introduced to improve the reliability of the data acquisition.

Analysis of Probability Distribution of Muzzle Velocity for Chrome Plated Barrel (크롬도금 포열의 포구속도 확률분포 특성 분석)

  • Kim, Jaekab;Kim, Jaehoon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.4
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    • pp.401-407
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    • 2021
  • To confirm the change of muzzle velocity and the most suitable probability distribution model of the 155 mm K9 howitzer barrel with chrome plating and changed rifling. Using a statistical program, the muzzle velocity were plotted on a normal distribution, a 2-parameter and 3-parameter Weibull distribution on a probability paper. Also, statistical parameters were estimated and muzzle velocity fitness test and probability of K676 charge were plotted. In both the chrome-plated with standard rifling and changed rifling for K9 barrel, the 2-parameter and 3-parameter Weibull distribution were skewed to the left compared to the normal distribution. It was confirmed that the muzzle velocity of the K9 barrel with chromium-plated is suitable for the normal distribution and 3-parameter Weibull distribution model.

A Study on the Mean Flow Velocity Distribution of Jeju Gangjung-Stream using ADCP (ADCP를 활용한 제주 강정천의 평균유속 분포 추정)

  • Yang, Se-Chang;Kim, Yong-Seok;Yang, Sung-Kee;Kang, Myung-Soo;Kang, Bo-Seong
    • Journal of Environmental Science International
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    • v.26 no.9
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    • pp.999-1011
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    • 2017
  • In this study, the Chiu-2D velocity-flow rate distribution based on theoretical background of the entropy probability method was applied to actual ADCP measurement data of Gangjung Stream in Jeju from July 2011 to June 2015 to predict the parameter that take part in velocity distribution of the stream. In addition, surface velocity measured by SIV (Surface Image Velocimeter) was applied to the predicted parameter to calculate discharge. Calculated discharge was compared with observed discharge of ADCP observed during the same time to analyze propriety and applicability of depth of water velocity average conversion factor. To check applicability of the predicted stream parameter, surface velocity and discharge were calculated using SIV and compared with velocity and flow based on ADCP. Discharge calculated by applying velocity factor of SIV to the Chiu-2D velocity-flow rate distribution and discharge based on depth of water velocity average conversion factor of 0.85 were $0.7171m^3/sec$ and $0.5758m^3/sec$, respectively. Their error rates compared to average ADCP discharge of $0.6664m^3/sec$ were respectively 7.63% and 13.64%. Discharge based on the Chiu-2D velocity-flow distribution showed lower error rate compared to discharge based on depth of water velocity average conversion factor of 0.85.

Flow and Heat Transfer Characteristics of a Circular Cylinder with the Periodic Inlet Velocity (주기적인 입구 속도 변동에 따른 원관 주위 유동 및 열전달 특성)

  • Ha, Ji Soo
    • Journal of the Korean Institute of Gas
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    • v.23 no.3
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    • pp.27-32
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    • 2019
  • In this study, the vorticity distribution and the temperature distribution change around a circular cylinder were compared and analyzed with time for constant inlet velocity and periodic inlet velocity. Also, the frequency characteristics of the flow were analyzed by analyzing the time variation of lift and drag and their PSD(power spectral density). In the case of constant inlet velocity, the well known Karman vorticity distribution was shown, and vortices were alternately generated at the upper and lower sides of the circular cylinder. In case of periodic inlet velocity, it was observed that vortex occurred simultaneously in the upper and lower sides of the circular cylinder. In both cases, it was confirmed that the time dependent temperature distribution changes almost the same behavior as the vorticity distribution. For the constant inlet velocity, the vortex flow frequency is 31.15 Hz, and for the periodic inlet velocity, the vortex flow frequency is equal to the preriodic inlet velocity at 15.57 Hz. The mean surface Nusselt number was 99.6 for the constant inlet velocity and 110.7 for the periodic inlet velocity, which showed 11.1% increase in surface heat transfer.

Measurement of Flow Field in a Ginseng Cleaner Model Using PIV (PIV에 의한 인삼세척기 모델 내부의 유동계측)

  • 송치성
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.1
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    • pp.139-145
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    • 2001
  • The objective of experimental study is to apply simultaneous measurement by PIV(Particle Image Velocimetry) to high_speed flow characteristics within ginseng cleaner model. Three different kinds of flow rate(15. 20, 27l/min) are selected as experimental condition. Optimized cross correlation identification to obtain velocity distribution, time-mean velocity distribution, velocity, profile, kinetic energy and turbulence intensity are represented quantitatively for the deeped understanding of the flow characteristics in a ginseng cleaner model.

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PIV Measurement and Flow Characteristics of Internal Flow Field within Ginseng Washing Machine (인삼세척기 내부유동장의 PIV계측 및 유동특성)

  • Na, Eun-Su;Song, Chi-Seong
    • 연구논문집
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    • s.30
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    • pp.59-65
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    • 2000
  • The objective of experimental study is to apply simultaneous measurement by PIV(Particle Image Velocimetry)to high_speed flow characteristics within Ginseng washing machine. Three different kinds of flow rate(15,20,27 $\ell$/min)are selected as experimental conditions. Optimized cross correlation identification to obtain velocity vectors is implemented by direct calculation of correlation coefficients. Instantaneous velocity distribution, time-mean velocity distribution and velocity profiles are represented quantitatively at the full-scale region for the deeper understanding of the flow characteristics in Ginseng washing machine.

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