• Title/Summary/Keyword: roe

Search Result 475, Processing Time 0.027 seconds

Mechanism of E. coli RNA polymerase-promoter interactions

  • Roe, Jung-Hye;Record.Jr, M.Thomas
    • The Microorganisms and Industry
    • /
    • v.13 no.1
    • /
    • pp.4-9
    • /
    • 1987
  • The regulation of gene expression in procaryotes is accomplished primarily at the level of transcription. Initiation of transcription is subject to numerous promoter-specific controls which act to ensure coordinate expression of disparate genes. The kinetics of formation of a functional("open") complex at a promoter, prior to the catalytic steps of RNA chain initiation and elongation, is thought to play a major role in controlling the efficiency of transcription of that promotor, since the subsequent processes of nucleotide binding and phosphodiester bond formation are rapid and are not promoter-specific (Mangel and Chamberlin, 1974 Shimamoto et al., 1981)

  • PDF

A Preconditioning Method for Two-Phase Flows with Cavitation

  • Shin B.R.;Yamamoto S.
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2003.10a
    • /
    • pp.181-182
    • /
    • 2003
  • A preconditioned numerical method for gas-liquid to-phase flow is applied to solve cavitating flow. The present method employs a density based finite-difference method of dual time-stepping integration procedure and Roe's flux difference splitting approximation with MUSCL-TVD scheme. A homogeneous equilibrium cavitation model is used. The method permits simple treatment of the whole gas-liquid two-phase flow field including wave propagation, large density changes and incompressible flow characteristics at low Mach number. By this method, two-dimensional internal flows through a venturi tuve and decelerating cascades are computed and discussed.

  • PDF

NUMERICAL INVESTIGATION OF INTERACTION BEHAVIOR BETWEEN CAVITATION BUBBLE AND SHOCK WAVE

  • Shin, Byeong-Rog;An, Young-Joon
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2008.03a
    • /
    • pp.215-220
    • /
    • 2008
  • A numerical method for gas-liquid two-phase flow is applied to solve shock-bubble interaction problems. The present method employs a finite-difference Runge-Kutta method and Roe's flux difference splitting approximation with the MUSCL-TVD scheme. A homogeneous equilibrium cavitation model is used. By this method, a Riemann problem for shock tube was computed for validation. Then, shock-bubble interaction problems between cylindrical bubbles located in the liquid and incident liquid shock wave are computed.

  • PDF

NUMERICAL INVESTIGATION OF INTERACTION BEHAVIOR BETWEEN CAVITATION BUBBLE AND SHOCK WAVE

  • Shin, Byeong-Rog;An, Young-Joon
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2008.10a
    • /
    • pp.215-220
    • /
    • 2008
  • A numerical method for gas-liquid two-phase flow is applied to solve shock-bubble interaction problems. The present method employs a finite-difference Runge-Kutta method and Roe's flux difference splitting approximation with the MUSCL-TVD scheme. A homogeneous equilibrium cavitation model is used. By this method, a Riemann problem for shock tube was computed for validation. Then, shock-bubble interaction problems between cylindrical bubbles located in the liquid and incident liquid shock wave are computed.

  • PDF

Hypersonic Viscous Interaction of Wedge Flows (극초음속 쐐기 유동의 Viscous Interaction)

  • Kim K. H.;Rho O. H.
    • 한국전산유체공학회:학술대회논문집
    • /
    • 1996.05a
    • /
    • pp.40-45
    • /
    • 1996
  • This paper discribes the viscous interaction of Hypersonic Wedge Flows using Roe FDS and AUSM+. For this purpose we developed the frozen and the equilibrium code and numerically simulated the viscous interaction by changing the surface temperature and the mach number. We used curve fitting data in NASA Reference Publication 1181, 1260 to calculate equilibrium properties. We compare the equilibrium flow with the frozen flow. We conclude that the mach number and the surface temperature are significant parameters, as the surface temperature and the mach number increase the viscous interaction becomes stronger, and we must consider high-temperature effects in hypersonic flow

  • PDF