The Experts below are selected from a list of 72 Experts worldwide ranked by ideXlab platform

Young-seok Choi - One of the best experts on this subject based on the ideXlab platform.

  • analyzing the shape parameter effects on the performance of the Mixed Flow Fan using cfd factorial design
    Journal of Mechanical Science and Technology, 2016
    Co-Authors: Uk-hee Jung, Joon-hyung Kim, Sung Kim, Jin-hyuk Kim, Young-seok Choi
    Abstract:

    Fans are representative turbo-machinery widely used for ventilation throughout the industrial world. Recently, as the importance of energy saving has been magnified with the Fans, the demand for the Fans with high efficiency and performance has been increasing. The representative method for enhancing the performance includes design optimization; in practice, Fan performance can be improved by changing the shape parameters such as those of meridional plane, impeller, and diffuser. Before optimizing the efficient design, a process of screening to select important design parameters is essential. The present study aimed to analyze the effects of Mixed-Flow Fans’ shape parameters on Fan performance (static pressure and Fan static efficiency) and derive optimum models based on the results. In this study, the shape parameters considered in the impeller domain are as follows: tip clearance, number of blades, beta angle of Leading edge (LE) in the blade, and beta angle of Trailing edge (TE) in the blade. The shape parameters considered in the diffuser domain are as follows: meridional length of the Guide vane (GV), number of GV, beta angle of LE in the GV and beta angle of TE in the GV. The effects of individual shape parameters were analyzed using the CFD (Computational fluid dynamic) and DOE (Design of experiments) methods. The reliability of CFD was verified through the comparison between preliminary Fan model’s experiment results and CFD results, and screening processes were implemented through 24-1 fractional factorial design. From the analysis of DOE results, it could be seen that the tip clearance and the number of blades in the impeller domain greatly affected the Fan performance, and the beta angle of TE at the GV in the diffuser domain greatly affected the Fan performance. Finally, the optimum models with improved Fan performance were created using linear regression equations derived from 24-1 fractional factorial design.

  • Analyzing the shape parameter effects on the performance of the Mixed-Flow Fan using CFD & Factorial design
    Journal of Mechanical Science and Technology, 2016
    Co-Authors: Uk-hee Jung, Joon-hyung Kim, Sung Kim, Jin-hyuk Kim, Young-seok Choi
    Abstract:

    Fans are representative turbo-machinery widely used for ventilation throughout the industrial world. Recently, as the importance of energy saving has been magnified with the Fans, the demand for the Fans with high efficiency and performance has been increasing. The representative method for enhancing the performance includes design optimization; in practice, Fan performance can be improved by changing the shape parameters such as those of meridional plane, impeller, and diffuser. Before optimizing the efficient design, a process of screening to select important design parameters is essential. The present study aimed to analyze the effects of Mixed-Flow Fans’ shape parameters on Fan performance (static pressure and Fan static efficiency) and derive optimum models based on the results. In this study, the shape parameters considered in the impeller domain are as follows: tip clearance, number of blades, beta angle of Leading edge (LE) in the blade, and beta angle of Trailing edge (TE) in the blade. The shape parameters considered in the diffuser domain are as follows: meridional length of the Guide vane (GV), number of GV, beta angle of LE in the GV and beta angle of TE in the GV. The effects of individual shape parameters were analyzed using the CFD (Computational fluid dynamic) and DOE (Design of experiments) methods. The reliability of CFD was verified through the comparison between preliminary Fan model’s experiment results and CFD results, and screening processes were implemented through 2^4-1 fractional factorial design. From the analysis of DOE results, it could be seen that the tip clearance and the number of blades in the impeller domain greatly affected the Fan performance, and the beta angle of TE at the GV in the diffuser domain greatly affected the Fan performance. Finally, the optimum models with improved Fan performance were created using linear regression equations derived from 2^4-1 fractional factorial design.

Timothy J. Newman - One of the best experts on this subject based on the ideXlab platform.

  • Tonal noise generation mechanisms in low-speed Mixed-Flow Fans
    20th AIAA CEAS Aeroacoustics Conference, 2014
    Co-Authors: Timothy J. Newman, Anurag Agarwal, Ann P. Dowling, R Stimpson
    Abstract:

    The applicability of aerospace Fan noise prediction theory to low-speed Fans operating at low Reynolds numbers is not precisely known. A low-speed Mixed-Flow Fan has been used as the initial test case to understand the dominant noise generating mechanisms in Fans of this type. In the absence of a universal transition model for CFD, the possibility of significant laminar Flow was considered. A simplified, theoretical model for predicting tonal noise is compared to experimental measurements made in a ducted aeroacoustic performance analysis rig. The Flow field was characterised in detail using two-dimensional hotwire measurements.

  • A six sensor method for measuring acoustic properties in ducts
    Journal of the Acoustical Society of America, 2013
    Co-Authors: Timothy J. Newman, Anurag Agarwal, Ann P. Dowling, Ludovic Desvard, Ryan Stimpson
    Abstract:

    An accurate description of sound propagation in a duct is important to obtain the sound power radiating from a source in both near and far fields. A technique has been developed and applied to decompose higher-order modes of sound emitted into a duct. Traditional experiments and theory based on two-sensor methods are limited to the plane-wave contribution to the sound field at low frequency. Due to the increase in independent measurements required, a computational method has been developed to simulate sensitivities of real measurements (e.g., noise) and optimize the set-up. An experimental rig has been constructed to decompose the first two modes using six independent measurements from surface, flush-mounted microphones. Experiments were initially performed using a loudspeaker as the source for validation. Subsequently, the sound emitted by a Mixed-Flow Fan has been investigated and compared to measurements made in accordance with the internationally standardized in-duct Fan measurement method. This method utilizes large anechoic terminations and a procedure involving averaging over measurements in space and time to account for the contribution from higher-order modes. The new method does not require either of these added complications and gives detail about the underlying modal content of the emitted sound.

Chao Qing Feng - One of the best experts on this subject based on the ideXlab platform.

  • Performance Research on the Axial Flow Fan Adding Guide Vane
    Advanced Materials Research, 2011
    Co-Authors: Wang Rui, Yichun Wang, Hong Fei Zheng, Chao Qing Feng
    Abstract:

    Fan is a major part of the cooling system in the vehicle, axial Flow Fan is used very common recently. In order to improve the cooling capability, cooling Fan’s structure has been changed; experiment research and numerical simulation are done for it. The result show that after adding guide vane to axial Flow Fan, its mass Flow increases. At the same speed, the mass Flow is increased by 20% when a rear guide vane is installed, and 15% of mass Flow increase when the front guide vane is installed, which indicates that a Mixed Flow Fan could be increased in Flow and improved in performance if the guide vanes are installed. Rear guide vane is better than front guide vane in the aspect of improving mass Flow. Take front guide vane as an example, adopting the NUMECA for numerical simulation, the result is as similar as the experiment’s.

R Stimpson - One of the best experts on this subject based on the ideXlab platform.

  • Tonal noise generation mechanisms in low-speed Mixed-Flow Fans
    20th AIAA CEAS Aeroacoustics Conference, 2014
    Co-Authors: Timothy J. Newman, Anurag Agarwal, Ann P. Dowling, R Stimpson
    Abstract:

    The applicability of aerospace Fan noise prediction theory to low-speed Fans operating at low Reynolds numbers is not precisely known. A low-speed Mixed-Flow Fan has been used as the initial test case to understand the dominant noise generating mechanisms in Fans of this type. In the absence of a universal transition model for CFD, the possibility of significant laminar Flow was considered. A simplified, theoretical model for predicting tonal noise is compared to experimental measurements made in a ducted aeroacoustic performance analysis rig. The Flow field was characterised in detail using two-dimensional hotwire measurements.

Hong Ming Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Numerical Simulation of Internal Flow Field in Mixed Flow Fan
    Advanced Materials Research, 2013
    Co-Authors: Yan Zhao Zhai, Hong Ming Zhang
    Abstract:

    The numerical simulation of internal Flow field of a Mixed-Flow Fan was carried out on the star-CD platform. Three-dimensional steady turbulent Flow is calculated using the standard k-ɛ turbulence model, and the pressure distribution, velocity distribution and other important Flow phenomenon inside the Fan are obtained. The number of meshes has important influence on the result, meanwhile, Fan inlet, impeller, outlet interact with each other. The results of numerical simulation can accurately analyze the Fan Flow field. The results of numerical simulation can accurately analyze the Fan Flow field structure, and provide guidance for further optimization and improvement of the Fan.