• Title/Summary/Keyword: 벽면의법칙

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Application of the "Law of the Wall" to Predict the Heat Transfer for Turbulent flow in a Rod Bundle (봉다발의 열전달 예측을 위한 "벽면의 법칙(Law of the Wall)" 적용)

  • 김내현
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.11
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    • pp.2111-2118
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    • 1992
  • In this study, an analytic model is developed to predict Nusselt numbers for turbulent flow in a rod bundle. Flow channel area is divided into several element channels, and simple algebraic equations of universal velocity and temperature profiles are integrated over each element channel. The integral equations are then added to yield an analytic expression for the nusselt number of a rod bundle. The analytic model reasonably predicts the available heat transfer data.

Velocity profile measurement of supersonic boundary layer over a flat plate using the PIV technique (PIV 기법을 이용한 초음속 평판 경계층의 속도 분포 측정)

  • Lee, Hyuk;Kim, Young Ju;Byun, Yung Hwan;Park, Soo Hyung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.6
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    • pp.477-483
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    • 2016
  • Velocity profiles of laminar, transition and turbulent boundary layers were investigated by using Particle Image Velocimetry(PIV) measurements on the flat plate at Mach 2.96. The Schlieren visualization and PIV measurements are also used to confirm whether the oblique shock wave generated from the leading edge affects the flow field over the flat plate. The laminar velocity profile measured from the experiment was well matched with the compressible Blasius solution. The velocity profile of the transition boundary layer was well correlated with the theoretical turbulent velocity profile from near the wall and the transition began from Re = $1.41{\times}106$. For the turbulent boundary layer, considering compressibility effects, the Van Driest-transformed velocity satisfies the incompressible log-law. It is found that the log region is extended farther in the wall-normal direction compared to the log region in incompressible boundary layer.