http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
THE FUNDAMENTAL SHOCK-VORTEX INTERACTION PATTERNS THAT DEPEND ON THE VORTEX FLOW REGIMES
장근식,바릭,장세명 한국전산유체공학회 2009 한국전산유체공학회지 Vol.14 No.3
The shock wave is deformed and the vortex is elongated simultaneously during the shock-vortex interaction. More precisely, the shock wave is deformed to a S-shape, consisting of a leading shock and a lagging shock by which the corresponding local vortex flows are accelerated and decelerated, respectively: the vortex flow swept by the leading shock is locally expanded and the one behind the lagging shock is locally compressed. As the leading shock escapes the vortex in the order of microseconds, the expanded flow region is quickly changed to a compression region due to the implosion effect. An induced shock is developed here and propagated against the vortex flow. This happens for a strong vortex because the tangential flow velocity of the vortex core is high enough to make the induced-shock wave speed supersonic relative to the vortex flow. For a weak shock, the vortex is basically subsonic and the induced shock wave is absent. For a vortex of intermediate strength, an induced shock wave is developed in the supersonic region but dissipated prematurely in the subsonic region. We have expounded these three shock-vortex interaction patterns that depend on the vortex flow regime using a third-order ENO method and numerical shadowgraphs.
多重連結된 유동영역을 위한 비압축성 와도-유동함수 Navier-Stokes 방정식의 수치해법
장근식,신순철,박성근 대한기계학회 1988 대한기계학회논문집 Vol.12 No.3
본 연구에서는 앞서의 '압력의 단가성' 개념을 재도입하여 유동함수의 경계치 설정에 수치적으로 유용하게 쓸 수 있음을 보였고, 이를 다중연결된 물체에 관한 2차 원 응용문제들에서 수렴성이 나쁘고 많은 계산시간을 요구하는 종래의 원시변수들을 이용한 수식화 과정을 벗어나, 이제는 간편하고 명확한 유동함수-와도의 방법으로 비 교적 적은 컴퓨터 시간으로 유동장의 계산이 가능하게 되었음을 보였다. To integrate the two-dimensional Navier-Stokes equations numerically in multiply-connected flow regions, the vorticity-stream function formulation is used. The steady stream function value at the surface of the multibody, initially unknown, has been determined interactively by introducing a line integral which requires the single-valuedness of pressure at each interaction step. This procedure is relatively simpler and more efficient than the primitive variable formulation which requires much more computing time and shows poor convergence. Three doubly-connected flow problems are defined and numerically analyzed by the present method. The results have been compared either with earlier existing ones or with the experimental interferograms to demon-strate the validity of the presented method.