• 제목/요약/키워드: normal flow

검색결과 1,928건 처리시간 0.026초

도플러 초음파를 이용한 개에서 마취에 따른 간문맥 혈류량 변화의 측정 (Estimation of portal blood flow using pulsed doppler ultrasound in the anesthetized dog)

  • 이영원
    • 대한수의학회지
    • /
    • 제38권3호
    • /
    • pp.659-663
    • /
    • 1998
  • Portal bood flow was measured with pulsed Doppler ultrasound in twenty anesthetized dogs. In anesthetized dogs with xylazine HCl, the average of portal blood flow velocity was reduced($11.68{\pm}1.55cm/sec$ vs. normal $16.67{\pm}1.77cm/sec$). Average portal blood flow was also decreased compared to normal($28.36{\pm}11.61ml/min/kg$ vs. normal $43.12{\pm}14.46 ml/min/kg$). And congestion index was increased($0.0368{\pm}0.0117cm{\cdot}sec$) vs. normal $0.0297{\pm}0.0062cm{\cdot}sec$). In anesthetized dogs with ketamine HCl, portal blood flow velocity was slightly increased ($22.62{\pm}2.53cm/sec$ vs. normal $16.67{\pm}1.77cm/sec$. Also mean portal blood flow was slightly increased($43.12{\pm}14.46ml/min/kg$ vs. normal $55.32{\pm}19.99ml/min/kg$). In anesthetized dogs with tiletamine and zolazepam, portal blood flow velocity and portal blood flow were unchanged.

  • PDF

Numerical Investigation of the Shock Interaction Effect on the Lateral Jet Controlled Missile

  • Min, Byung-Young;Lee, Jae-Woo;Byun, Yung-Hwan
    • 한국추진공학회:학술대회논문집
    • /
    • 한국추진공학회 2004년도 제22회 춘계학술대회논문집
    • /
    • pp.357-364
    • /
    • 2004
  • A computational study on the supersonic flow around the lateral jet controlled missile has been performed. Case studies have been performed by comparing the normal force coefficient and the moment coefficient of a missile body for several different jet flow conditions, angle of attacks, circumferential jet locations, and spouting jet angles. For the several different jet flow conditions, which include the jet pressure, the jet Mach number, and the corresponding jet mass flow rate, the results show that the normal force coefficient is almost proportional to the jet thrust but the moment coefficient is not. Distinctly different flow phenomena can be noticed as the pressure ratio and the jet Mach number increase. By investigating the angle of attack effect to the normal force and the pitching moment, it has been identified that the normal force and the pitching moment show nonlinearity with respect to the angle of attack. From the detailed flow field analyses with respect to the jet flow conditions and the angle of attacks, it is verified that most of the normal force loss and the pitching moment generation are taken place at the low-pressure region behind the jet nozzle. Furthermore, the normal force and the pitching moment characteristics of the missile have been identified by comparing different circumferential jet locations and spouting jet angles.

  • PDF

예외 흐름 분석을 정상 흐름 분석과 분리하여 Java프로그램에 대한 제어 흐름 그래프를 생성하는 방법 (A Method to Construct Control Flow Graphs for Java Programs by Decoupling Exception Flow Analysis from Normal Flow Analysis)

  • 조장우;창병모
    • 한국정보과학회논문지:소프트웨어및응용
    • /
    • 제31권5호
    • /
    • pp.643-650
    • /
    • 2004
  • 제어 흐름 그래프는 자료 흐름 분석과 제어 종속 분석과 같은 프로그램 분석 분야와 프로그램 슬라이싱과 테스팅과 같은 소프트웨어공학 분야에서 필요로 하는 정보이다. 이러한 분석들이 안전하고 유용하기 위해서는 제어 흐름 그래프는 예외 흐름을 포함해야 한다. 기존의 방법은 예외 흐름과 정상 흐름의 상호 의존적인 관계로 인해 두 흐름을 동시에 계산하면서 제어 흐름 그래프를 생성한다. 그러나 실제 Java 프로그램을 조사해 본 결과 두 흐름이 상호 의존적으로 필요한 경우는 거의 발생하지 않음을 알 수 있었다. 그러므로 정상 흐름과 예외 흐름을 분리해서 계산할 수 있음을 알았고, 예외 흐름을 계산하는 예외 흐름 분석을 제안한다. 그리고 예외 흐름을 표현하는 예외 흐름 그래프를 제안한다. 그리고 제어 흐름 그래프는 예외 흐름 그래프와 정상 흐름 그래프를 합병함으로써 생성될 수 있음을 보인다.

원형관에서 상대수심을 고려한 점변류 해석 (Analysis of Gradually Varied Flow Considering Relative Depth in Circular Pipe)

  • 김민환;박정희;송창수
    • 상하수도학회지
    • /
    • 제21권3호
    • /
    • pp.287-294
    • /
    • 2007
  • When we use the circular pipes for wastewater and storm water, we should be known the characteristics of the flow for accurate design. To elevate the design accuracy, we want to know the profile of flow. The roughness coefficient in the Manning equation is constant, but in actuality changed with the relative depth in circular pipe. This study was conducted to calculate the relative normal depth in changing the roughness coefficient (named relative roughness coefficient) with the relative depth in the analysis of gradually varied flow in the circular pipe by Newton-Raphson method. We performed the analysis of gradually varied flow using the relative normal depth and the relative roughness coefficient. We presented the 12 flow profiles with the relative depth and the relative roughness coefficient in circular pipe. The flow classification considering relative depth in circular pipe is available to analyse gradually varied flow profiles.

유역모형을 이용한 비점배출계수 적용성 평가 (Evaluation of Applicability for Nonpoint Discharge Coefficient using Watershed Model)

  • 이은정;김태근
    • 환경영향평가
    • /
    • 제21권3호
    • /
    • pp.339-352
    • /
    • 2012
  • Total maximum daily load have been implemented and indicated that nonpoint discharge coeffients in flow duration curve were 0.50 of Normal flow duration ($Q_{185}$) and 0.15 of low flow duration($Q_{275}$). By using SWAT, nonpoint discharge coefficients are studied with the conditions of the instream flow and the rainfall in two study areas. The nonpoint discharge coefficient average of BOD and TP for normal flows duration in 3 years are 0.32~0.36 and 0.28~0.31. For the low flow duration, the nonpoint discharge coefficient avergae of BOD and TP were 0.10~0.12 and 0.10~0.11. These are lower than the coefficients of total maximum load regulation. There are big differences between one of regulation and one of SWAT for the normal flow duration. With the consideration of rainfall condition, the nonpoint discharge coefficient of flood flow duration are influenced on the amount of rainfalls. However, the nonpoint discharge coefficients of normal flow duration and low flow duration are not effected by the rainfall condition. Since the spatial distribution and geomorphological characteristics could be considered with SWAT, the estimation of nonpoint discharge coefficient in watershed model is better method than the use of the recommended number in the regulation.

하나로 원형 조사공의 안내관 제트유동 억제에 대한 해석 (The Analytic Analysis of Suppressing Jet Flow at Guide Tube of Circular Irradiation Hole in HANARO)

  • 박용철;우상익
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 2004년도 춘계 학술대회논문집
    • /
    • pp.214-219
    • /
    • 2004
  • The HANARO, a multi-purpose research reactor of 30 MWth, open-tank-in-pool type, has been under normal operation since its initial criticality in February, 1995. The HANARO is composed of inlet plenum, grid plate, core channel with flow tubes and chimney. The reactor core channel is located at about twelve m (12 m) depth of the reactor pool and cold by the upward flow that the coolant enters the lower inlet of the plenum, rises up through the grid plate and the core channel and exit through the outlet of chimney. A guide tube is extended from the reactor core to the top of the reactor chimney for easily un/loading a target under the reactor normal operation. But active coolant through the core can be Quickly raised up to the top of the chimney through the guide tube by jet flow. This paper is described an analytical analysis to study the flow behavior through the guide tube under reactor normal operation and unloading the target. As results, it was conformed through the analysis results that the flow rate, about fourteen kilogram per second (14 kg/s) suppressed the guide tube jet and met the design cooling flow rate in a circular flow tube, and that the fission moly target cooling flow rate met the minimum flow rate to cool the target.

  • PDF

초음속디퓨져에서 발생하는 수직충격파의 난류경계층의 간섭에 관한 실험 (A New Experiment on Interaction of Normal Shock Wave and Turbulent Boundary Layer in a Supersonic Diffuser)

  • 김희동;홍종우
    • 대한기계학회논문집
    • /
    • 제19권9호
    • /
    • pp.2283-2296
    • /
    • 1995
  • Experiments of normal shock wave/turbulent boundary layer interaction were conducted in a supersonic diffuser. The flow Mach number just upstream of the normal shock wave was in the range of 1.10 to 1.70 and Reynolds number based upon the turbulent boundary layer thickness was varied in the range of 2.2*10$^{[-994]}$ -4.4*10$^{[-994]}$ . The wall pressures in streamwise and spanwise directions were measured for two test cases, in which the turbulent boundary layer thickness incoming into the supersonic diffuser was changed. The results show that the interactions of normal shock wave with turbulent boundary layer in the supersonic diffuser can be divided into three patterns, i.e., transonic interaction, weak interaction and strong interaction, depending on Mach number. The weak interactions generate the post-shock expansion which its strength is strong as the Mach number increases and the strong interactions form the pseudo-shock waves. From the spanwise measurements of wall pressure, it is known that if the flow Mach number is low, the interacting flow fields essentially appear two-dimensional, but they have an apparent 3-dimensionality for the higher Mach numbers.

임피던스 혈량측정법을 이용한 손가락 혈류량의 측정 (Development of Impedance Plethysmography and Measurement of Digital blood Flow)

  • 김덕원;송철규;김원기;이명호
    • 대한의용생체공학회:학술대회논문집
    • /
    • 대한의용생체공학회 1991년도 춘계학술대회
    • /
    • pp.71-73
    • /
    • 1991
  • In this study electrical impedance plethysmograph was developed and each ten digital blood flow was measured for eight normal males and a patint with digital arterial reconstruction surgery. Blood flow of the digit with surgery was approximately fourty percent compared to that of the other normal digit. For the normal subjects, right-handed subjects generally have larger blood flow in right fingers than that in left fingers while it was reverse for the left-handed subjects. The relative average magnitude of the digital blood flow is the third, first, second, fourth, and fifth digit in descending order for the left and right hand, respectively. Blood flow of the fifth digit for all subjects except one was the smallest among the five digits.

  • PDF

Effect of Inlet Direction on the Refrigerant Distribution in an Aluminum Flat-Tube Heat Exchanger

  • Kim, Nae-Hyun;Kim, Do-Young;Byun, Ho-Won;Choi, Yong-Min
    • International Journal of Air-Conditioning and Refrigeration
    • /
    • 제16권4호
    • /
    • pp.130-136
    • /
    • 2008
  • The refrigerant R-134a flow distributions are experimentally studied for a round header/ten flat tube test section simulating a brazed aluminum heat exchanger. Three different inlet orientations(parallel, normal, vertical) were investigated. Tests were conducted with downward flow for the mass flux from 70 to 130 $kg/m^2s$ and quality from 0.2 to 0.6. In the test section, tubes were flush-mounted with no protrusion into the header. It is shown that normal and vertical inlet yielded approximately similar flow distribution. At high mass fluxes or high qualities, however, slightly better results were obtained for normal inlet configuration. The flow distribution was worst for the parallel inlet configuration. Possible explanation is provided based on flow visualization results.

Flow Interaction of Shedding Vortex with Injected Normal Blowing

  • ;이창진;구희석
    • 한국추진공학회:학술대회논문집
    • /
    • 한국추진공학회 2012년도 제38회 춘계학술대회논문집
    • /
    • pp.239-243
    • /
    • 2012
  • This paper is concerned with turbulent flow computations using Large Eddy Simulation (LES) and the flow interaction of vortex shedding in a cylindrical duct flow driven by mass blowing through the wall. The purpose is to analyze non-linear combustion characteristics in the presence of vortex shedding generated in a hybrid rocket motor. Experimental studies have shown sudden changes in pressure (referred as a DC-shift), which depend on the strength of vortex strength of incoming flow. The combustion instability because of a sudden change in pressure fluctuations is mainly related with the interaction between vortex shedding. Therefore LES computation on a duct with injected normal blowing was performed to simulate the turbulent flow interactions with the behaviors of vortices and vortex structures along the injected wall.

  • PDF