• Title/Summary/Keyword: swirling Flow

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Study on the Experimental Optimization of DOHC Intake Port Shape for Swirl Generation (선회류 생성 DOHC 흡기포트 형상의 실험적 최적화에 관한 연구)

  • 김재웅;최영돈
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.2
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    • pp.149-161
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    • 1997
  • Masked intake ports of a DOHC gasoline engine were divised and the shape was optimized to maximize the swirling and tumbling motions in the cylinder. Performances of the ports, swirling number, tumbling number and discharge coefficient were measured by Ricardo's rig test. By combination of the angle and height of the protrusions in the intake ports wall, swirling and tumbling strength can be controlled and the port shape can be optimized to increase the swirling number 13 times and tumbling number 2 times larger than those of an original port of DOHC engine with the expense of 3% decrease of discharge coefficient.

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A Study on the Characteristics of Combustion Products of Swirling Furnace (선회분류 연소로의 연소 생성물 특성에 관한 연구)

  • 심순용;노재성;이창식
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.3
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    • pp.113-122
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    • 1994
  • This paper describes the effects of combustion parameters on the characteristics of combustion products in swirling flow furnace. The concentration of combustion products and temperature distribution of flow field in the furnace have been investigated by numerical method. The fuel was injected into the furnace and the swirling device was constructed with three kinds of vane swirler at inlet port of furnace. The results of this study showed that the effect of combustion parameters on the concentration characteristics of carbon monoxide and nitrogen monoxide of combustion products. It was found that the pollutant formation wad dependent on the equivalence ratio and swirl intensity level.

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Numerical Calculation of the Swirling Flow in a Centrifugal Compressor Volute (원심압축기 벌류트 내부의 스월 유동에 관한 수치해석)

  • Seong, Seon-Mo;Kang, Shin-Hyoung;Cho, Kyung-Seok;Kim, Woo-June
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2603-2608
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    • 2007
  • Flows in the centrifugal compressor volute with circular cross section are numerically investigated. The computational grid for the calculation utilized a multi-block arrangement to form a butterfly grid and flow calculations are performed using commercial CFD software, CFX-TASCflow. The centrifugal compressor of this study has axial diffuser after radial diffuser because of the shape of inlet duct and installation constraints. Due to this feature the swirling flow pattern is different from the other investigations. The flow inside volute is very complex and three dimensional with strong vortex and recirculation through volute tongue. The calculation results show circumferential variations of the swirl and through flow velocity and pressure distribution. The mechanism deciding flow structure is explained by considering the force balance in volute cross section. And static pressure recovery and total pressure loss are estimated from the calculated results and compared with Japikse model.

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An Experimental Study on Swirl Fluctuation Velocity in a Horizontal Circular Tube (수평원통관에서 선회유동의 난동속도에 관한 실험적 연구)

  • Chang Tae-Hyun;Kim Hee-Young
    • Journal of the Korean Society of Visualization
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    • v.1 no.2
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    • pp.29-37
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    • 2003
  • During the past five decades or so, the characteristics of turbulent swirling flow have been studied extensively because of its great technological and scientific importance. It is well known that the swirling flow improves heat transfer in duct flow. The reason for this is due to the effect of streamline curvature associated with the tangential velocity component. Although many studies have been carried out to investigate the characteristics of the swirling flow in a circular tube. The experimental methods for measuring the velocity components are by hot-wire or LDV (Laser-Doppler-Velocimetry) measuring single point velocity so far. The present study was aimed to analyse the flow characteristics of swirling flow such as time-mean velocity vector, local velocity turbulence intensity and turbulence kinetic energy by using PIV(Particle-Image Velocimetry). The experiment was carried out for four Reynold numbers $1.0\times10^{4}$, $1.5\times10^{4}$, $2.0\times10^{4}$ and $2.5\times10^{4}$ of the measuring area.

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Experimental Study on Heat Transfer with Swirling Flow in a Cylindrical Annuli (원형동심관내 선회유동의 열전달에 대한 실험적 연구)

  • Chang, Tae-Hyun;Kil, Sang-Cheol;Lee, Kwon-Soo
    • Journal of the Korean Society of Visualization
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    • v.8 no.1
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    • pp.53-60
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    • 2010
  • Experimental investigations were conducted to study the characteristics of turbulent swirling flow in an axisymmetric annuli. Swirl angle measurements were performed using a flow visualization technique using smoke and dye liquid for Re=60,00080,000. Using the two-dimensional particle image velocimetry method, we found the time-mean velocity distribution and turbulent intensities in water with swirl for Re=20,000, 30,000, and 40,000 along longitudinal sections. Neutral points occurred for equal axial velocity at y/(R-r)=0.70.75, and the highest axial velocity was recorded near y/(R-r)=0.9. Negative axial velocity was observed near the convex tube along X/(D-d)=3~23. Another experimental study was performed to investigate heat transfer characteristics of turbulent swirling flow in an axisymmetric annuli. Static pressure, and local flow temperature were measured using tangential inlet condition and the friction factors and Nusselt number were calculated for several Reynolds numbers.

Investigation of the Swirling Flow Fields of a Gun-Type Gas Burner by the Measurement of a Five-Hole Pressure Probe (5공 압력프로브의 측정에 의한 Gun식 가스버너의 스월유동장 고찰)

  • Kim, Jang-Kweon;Oh, Seok-Hyung
    • Journal of Power System Engineering
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    • v.19 no.1
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    • pp.19-23
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    • 2015
  • The swirling flow fields of a gun-type gas burner(GTGB) without a combustion chamber were measured by a straight-type five-hole pressure probe(FHPP) under the cold flow condition. The three kinds of velocity components and the static pressure were calculated by using a non-nulling calibration method covering the velocity reduction performance of the effective flow attack angle of ${\pm}80^{\circ}$. As a result, the velocity and static pressure measured by a FHPP comparatively shows the better performance on the swirling flow of a GTGB than those measured by X-probe.

A Study on Swirling Flow in a Vertical Circular Tube (수직원통관에서 선회유동의 속도분포에 관한 연구)

  • Chang, Tae-Hyun;O, Geon-Je;Lee, Hae-Soo;Kim, Sang-Youn;Doh, Deog-Hee
    • Journal of the Korean Society of Visualization
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    • v.9 no.3
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    • pp.16-23
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    • 2011
  • Experiment and numerical investigation are performed on swirling water flow in a vertical circular tube. This kind of flow is used in heat exchangers, combustion chambers, thermal power plants, and other mechanical equipment to move slurries or to convey materials. However, limited information on swirling flow in vertical circular tubes is available. In the current paper, the three-dimensional particle image velocimetry(PIV) technique is employed to compare the measured velocity profiles of water along the vertical circular tube with those of non-swirl flow. In addition, computational fluid dynamics(CFD) code was applied to calculation of the flow velocities with swirl.

Application of non-reacting and reacting flow simulation for combustor development (연소기 개발에서 시뮬레이션 기술의 활용)

  • Jung, Seungchai;Yang, Siwon;Kim, Shaun;Park, Heeho;Ahn, Chulju;Yoon, Samson
    • 한국연소학회:학술대회논문집
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    • 2013.06a
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    • pp.123-126
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    • 2013
  • Combustor development requires high fidelity simulation capable of predicting recirculation zone (RZ), temperature field, and pollutant emission. Swirling flow is widely used in combustor for its benefits in efficient mixing and flame stabilization by RZ. Large eddy simulation (LES) is used to calculate swirling flow in an expanding pipe [1], and shows higher accuracy than RANS. Reactive flow modeling using LES and flamelet model is validated with experiments by Barlow et al. [4] and Masri et al. [3]. Finally, heat transfer simulation of Samsung Techwin's combustor liner is presented.

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Freezing of Water in Von-Kármán Swirling Flow (Von-Kármán 회전 유동 하에서의 물의 결빙)

  • Yoo, J.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.8 no.3
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    • pp.413-422
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    • 1996
  • Freezing of water in von-$K{\acute{a}}rm{\acute{a}}n$ swirling flow is considered. The transient behavior of the temperature distribution in both solid and liquid phases and freezing rate are determined. The fluid flow induced by the rotation of solid strongly inhibits the freezing process. The thickness of frozen layer is inversely proportional to the square root of the angular velocity of solid. As the angular velocity or initial liquid temperature becomes larger, the freezing process is more strongly inhibited by the fluid flow. When phase change is present, the transient heat transfer rate is greater than the case with no phase change.

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Experimental Study and Numerical Simulation of Cavity Oscillation in a Diffuser with Swirling Flow

  • Chen, Chang-Kun;Nicolet, Christophe;Yonezawa, Koichi;Farhat, Mohamed;Avellan, Francois;Miyazawa, Kazuyoshi;Tsujimoto, Yoshinobu
    • International Journal of Fluid Machinery and Systems
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    • v.3 no.1
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    • pp.80-90
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    • 2010
  • The cavity oscillation with swirling flow in hydraulic power generating systems was studied by a simple experiment and numerical simulation. Several types of fluctuation were observed in the experiment, including the cavitation surge caused by the diffuser effect and the vortex precession by the swirling flow. Both cavitation surge and vortex precession were simulated by CFD. Detailed flow structure was examined through flow visualization and CFD.