• Title/Summary/Keyword: Fluent Model

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A RANS CFD Based Approach for Resistance, Maneuvering and Seakeeping

  • Sasanapuri, Balasubramanyam;Wilson, Wesley;Rhee, Shin-Hyung
    • Journal of Ship and Ocean Technology
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    • v.11 no.4
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    • pp.55-71
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    • 2007
  • The primary objective of this work is to develop methodologies for virtual model basin and to demonstrate the capabilities for generic multi-hull ship geometry. A computational fluid dynamics approach is used to simulate various model basin tests for steady resistance, maneuvering and seakeeping. For a catamaran hull configuration, the methodologies are used for solving these problems and the results are discussed. Computational results are compared with the results of a benchmarked potential flow theory method for calm water resistance.

Numerical Analysis for the Flow Field past a Two-Staged Conical Orifice (이단 원추형 오리피스를 지니는 유동장에 대한 수치해석)

  • Kim, Yeon-Soo;Kim, You-Gon
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.499-505
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    • 2001
  • The objective of the paper was to measure the pressure drop and to investigate the recirculation region of the conical orifices used in Kwang-yang Iron & Steel Company. The flow field with water used as a working fluid was the turbulent flow for Reynolds number of $2{\times}10^4$. The effective parameters for the pressure drop and the recirculation region were the conical orifice's inclined angle (${\theta}$) against the wall, the interval(L) between orifices, the relative angle of rotation(${\alpha}$) of the orifices, the shape of the orifice's hole(circle, rectangle, triangle) having the same area. It was found that the shape of the orifice's hole affected the pressure drop and the flow field a lot, But the other parameters did not make much differences to the pressure drop. The PISO algorithm with FLUENT code was employed.

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Estimation of Flow Uniformity in Water Tunnel by Using CFD Analysis (전산유동 해석을 이용한 수동의 유동 균질성 평가)

  • Lim, Y.T.;Chang, J.W.;Kim, M.S.
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.12 no.3
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    • pp.13-24
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    • 2004
  • It is easier to view flow visualization by using a water tunnel rather than a smoke wind tunnel because of low speed at same Reynolds number. Using a water tunnel also produces more definite flow visualization by the use of various color dyes. The flow uniformity in test section is very significant for accuracy of the test because most flow experiments elicit results through the installation of a model in uniform flow. The purpose of small-size desktop-type water tunnel is not to produce quantitative measurements, but rather to give a visualization of the fluid flow phenomenon. However, uniformity in the test section affects the accuracy of the results. Accordingly, this research estimates uniformity in a water tunnel test section by using the commercially available CFD code FLUENT. Results of the CFD analysis show that the flow uniformity of the test section is good.

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The Effect of Flue-gas Recirculation on Combustion Characteristics of Self Regenerative Low NOx Burner (자기축열식 저 NOx 연소기에서 배가스 재순환이 연소특성에 미치는 영향)

  • Kang, Min-Wook;Kim, Jong-Gyu;Dong, Sang-Keun;Yoon, Young-Bin
    • Journal of the Korean Society of Combustion
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    • v.8 no.1
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    • pp.17-24
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    • 2003
  • The conventional regenerative system has a high thermal efficiency as well as energy saving using the high preheated combustion air. in spite of these advantages, it can not avoid high nitric oxide emissions. Recently, flameless combustion has received much attention to solve these problems. In this research, numerical analysis is performed for flow-combustion phenomena in the self regenerative burner. In this analysis we used Fluent 6.0 code. the that is developed for commercial use, Methane gas is used as a fuel and two-step reaction model for methane and Zeldovich mechanism for NO generation are used. the velocity of the preheated combustion air is used as a parameter and we analyze the characteristics of flow-field, temperature distributions and NO emissions. Due to the increased recirculation rate, the maximum temperature of flame is significantly increased and NOx emissions is reduced.

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Preliminary Experimental Results of Pressure Control for Modulatable Thruster Applications (노즐목 가변 추력기의 압력제어 기법에 관한 예비실험 결과)

  • Choi, Jae-Sung;Huh, Hwan-Il
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.18-21
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    • 2011
  • In this study, basic research on the pressure control using driven pintle of modulatable thruster is presented. For this purpose, pintle thruster and pintle shape was developed. The actuator model was selected by calculating pintle load using Fluent software. Preliminary unsteady experimental results show that huge pressure oscillation is occurred as the pintle approach toward nozzle wall. From the preliminary experimental results, we could see possibility of pressure control of the modulatable thruster.

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Fluid-structure interaction simulation of a floating wave energy convertor with water-turbine driven power generation

  • Zullah, Mohammed Asid;Lee, Young-Ho
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.8
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    • pp.710-720
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    • 2016
  • The Floating Wave Energy Convertor (FWEC) mooring design has an important requirement associated with the fact that, for a wave energy converter, the mooring connections may interact with their oscillations, possibly modifying its energy absorption significantly. It is therefore important to investigate what might be the most suitable mooring design according to the converter specifications and take into account the demands placed on the moorings in order to assure their survivability. The objective of this study is to identify a computational fluid dynamics method for investigating the effects of coupling a wave energy device with a mooring system. Using the commercial software ANSYS AQWA and ANSYS FLUENT, a configuration was studied for different displacements from the equilibrium position, load demands on the moorings, and internal fluid motion. These results and findings form a basis for future efforts in computational model development, design refinement, and investigation of station keeping for FWEC units.

Analysis of Performance of Turbine Exhaust Nozzle for Liquid Rocket Engine (액체로켓엔진의 터빈 배기노즐 성능 해석)

  • Cho, Won-Kook;Seol, Woo-Seok
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.316-319
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    • 2008
  • A computational analysis has been conducted on the compressible flow in the turbine exhaust nozzle of the gas generator cycle liquid rocket engine. The commercial CFD code Fluent has been used. Four nozzle designs have been compared to select the turbine exhaust nozzle concept. Three candidates with single nozzle have comparable performance. The model with bifurcated nozzles shows significant performance loss. However it will be better in the view of balanced thrust distribution because of its symmetric geometry.

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Numerical Simulation of Cold Storage and Preservation of Hanfu Apple

  • Gong, Yuan Juan;Zhang, Yan;Ning, Xiao Feng
    • Journal of Biosystems Engineering
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    • v.41 no.3
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    • pp.184-192
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    • 2016
  • Purpose: To solve the decay phenomenon of Hanfu apples that occurs during storage and obtain the best environmental parameters for preserving Hanfu apples using Fluent. Methods: Preservation storage was designed by analyzing the characteristics of Hanfu-apple storage and the natural environment in northeast China. The boundary conditions and simulation of a preservation model were established. Results: Compared with the initial values, the hardness decreased by $1.95kg/cm^2$, the sugar-acid ratio decreased by 20.43, and weight-loss rate was 3.98%. Conclusion: The results for the temperature field and velocity field of the empty storage were analyzed using Fluent. Hanfu apples can maintain good quality during the period of storage, according to our analysis of the Hanfu-apple hardness, weight loss, and change in the sugar-acid ratio during the 90-day preservation period.

The effect of flue-gas recirculation on combustion characteristics of regenerative low NOx burner (축열식 저 NOx 연소기의 배가스 재순환이 연소특성에 미치는 영향)

  • Kang, Min-Wook;Yoon, Young-Bin;Dong, Sang-Keun
    • 한국연소학회:학술대회논문집
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    • 2002.11a
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    • pp.97-104
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    • 2002
  • The conventional regenerative system has a high thermal efficiency as well as energy saving using the high preheated combustion air. in spite of these advantages, it can not avoid high nitric oxide emissions. Recently, flameless combustion has received much attention to solve these problems. In this research, numerical analysis is performed for flow-combustion phenomena in the self regenerative burner. In this analysis we used Fluent 6.0 code. the that is developed for commercial use, Methane gas is used as a fuel and two-step reaction model for methane and Zeldovich mechanism for NO generation are used. the velocity of the preheated combustion air is used as a parameter and we analyze the characteristics of flow-field, temperature distributions and NO emissions. Due to the increased recirculation rate, the maximum temperature of flame is significantly increased and NOx emissions is reduced

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