• International Journal of Fluid Machinery and Systems
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• v.8 no.3
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• pp.132-141
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• 2015

This paper presents a CFD-based methodology for the prediction of guide vane torque in hydraulic turbine distributor for aligned and misaligned configurations. A misaligned or desynchronized configuration occurs when the opening angle of one guide vane differs from the opening angle of all other guide vanes, which may lead to a torque increase on neighbouring guide vanes. A fully automated numerical procedure is presented, that automates computations for a complete range of operation of a 2D or 3D distributor. Results are validated against laboratory measurements.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.3
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• pp.35-43
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• 2019

In this study, a guide vane with varying positions and incidence angles was adopted to a pin-fin channel to analyze the change in thermal performance and pressure loss characteristics. A numerical analysis was conducted to investigate the effect of incidence angles and positions on heat transfer and flow characteristics at Re =1400. The results of it were compared those of a pin-fin channel without a guide vane. In case 1 when the incidence angle is $0^{\circ}$, the heat transfer performance is maximized and improved by approximately 5% when compared to the pin-fin channel without the guide vane. In case 2 when the incidence angle is $10^{\circ}$, the pressure loss is minimized and decreased by approximately 1.9% when compared to the pin-fin channel without the guide vane.

• The KSFM Journal of Fluid Machinery
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• v.14 no.1
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• pp.66-76
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• 2011

The heat transfer and pressure loss characteristics of a rotating two-pass channel with a guide vane in the turning region have been studied using three-dimensional Reynolds-averaged Navier-Stokes (RANS) analysis, and the shape of the guide vane has been optimized using surrogate modeling optimization technique. For the optimization, thickness, location and angle of the guide vanes have been selected as design variables. The objective function has been defined as a linear combination of the heat transfer and the friction loss related terms with a weighting factor. Latin hypercube sampling has been applied to determine the design points as design of experiments. A weighted-average surrogate model, PBA has been used as the surrogate model. The guide vane in the turning region does not influence the heat transfer in the first passage upstream of the turning region, but enhances largely the heat transfer in the turning region and the second passage. In an example of the optimization, the objective function has been increased by 13.6%.

• Journal of the Korean Solar Energy Society
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• v.27 no.2
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• pp.79-85
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• 2007

The performance of in-line duct fan depends on the design parameters of impeller and guide vane such as sweep back angle of impeller hub, guide vane angle etc. In this study four kinds of impellers having different sweep back angles, $0^{\circ}$, $17.5^{\circ}$, $35^{\circ}$, $52.5^{\circ}$ with 8 guide vanes, and different guide vane angles, $15^{\circ}$, $30^{\circ}$, $45^{\circ}$ were selected and their performance measured to investigate the effects of design parameters. The results show that both sweep back angle of impeller hub and the guide vane angle have large effect on the efficiency. Especially, it was found that the mixed flow impellers having sweep back angle between $17.5^{\circ}$ and $35^{\circ}$ gave good performances for in-line duct fan.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.373-377
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• 2005

The Performance of in-line duct fan depends on the design parameters of impeller and guide vane. such as sweep back angle of impeller, the number of blades, outlet blade angle, guide vane angle etc. In this experimental study total four kinds of impellers having different sweep back angles, $90^{\circ},\;72.5^{\circ},\;55^{\circ},\;37.5^{\circ}$ with 8 guide vanes, different the number of blades, 6ea, 8ea, 10ea, 12ea, different kinds of outlet blade angles, $30^{\circ},\;45^{\circ}.\;60^{\circ}$ and different kinds of guide vane angles, $15^{\circ},\;30^{\circ},\;45^{\circ}$ were selected and their performance measured to investigate the effects of them. The results were non-dimensionalized to compare their performance.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.10
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• pp.1267-1274
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• 2012

A guide vane plays a key role in controlling the flow rate of water supplied to the turbine of a hydropower plant. It has been reported that guide vane bearing bushings are subjected to considerable wear, which requires them to be maintained. An ancillary service such as frequency control and black start causes cyclic low opening operation of the guide vanes. It is empirically well known that such operation increases the wear rate of the guide vane bearing bushing. In this study, the effect of low opening operation on the increasing wear of the guide vane bearing bushing is quantitatively assessed via finite element flow analysis, finite element stress analysis, and relative wear evaluation. As a result of the assessment, it is identified that the pressure applied on the guide vane surface increases and the contact length between the outer surface of the guide vane stem and the inner surface of the bearing bushing decreases with a decrease in the opening of the guide vane. In addition, low opening of the guide vanes results in an increase in the relative wear owing to the generation of high contact pressure on the bearing bushing surfaces.

• 한국전산유체공학회:학술대회논문집
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• 2002.10a
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• pp.150-155
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• 2002

A commercial CFD code is applied to analyze the 3-D viscous flow field within vertical multi-stage centrifugal pump including impeller with 6 blades and guide vane with 11 blades and is performed by changing flow rate from 10 to $26m^3/h$ at the constant 3500rpm. The purpose of this 3-D numerical simulation is not only to confirm how much the effect of three kinds of blade inlet breadth (11mm, 11.5mm, 12mm) of impeller has influence on the performance of vertical multi-stage pump but also to make clear the cause about performance difference at the exit side of impeller and guide vane. The vertical multi-stage pump consisit of the impeller, guide, vane and cylinder. The grid of numerical analysis used to the vertical multi-stage pump is 18,000, 45,000, and 100000 cells in case of the impeller, guide vane, cylinder and total grid is 730,000 cells. The characteristics such as total pressure coefficient, total head, shaft horse power, power efficiency at the exit side of impeller and guide vane, discharge coefficient are represented according to flow rage changing.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.8
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• pp.580-588
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• 2009

This paper summarizes the experimentally-measured performance of small-scale, vertical-axis wind turbine for the purpose of improving the aerodynamic efficiency and its controllability. The turbine is designed to have a Savonius-Type rotor with an inlet guide-vane and an side guide-vane so that it achieves a higher efficiency than any lift- or drag-based turbines. The main design factors for this high-efficient, vertical wind turbine are the number of blades (Z), and the aspect ratio of Height/Diameter (H/D) among many. The basic model has the diameter of 580mm, the height of 464mm, and the blade number of 10. The maximum power coefficient of 0.50 was experimentally measured for the above-mentioned specifications. The inlet-guide vane ensures the maximum efficiency when the angle of attack to the rotor blade lies between $15^{\circ}$ and $20^{\circ}$. This experimental results for the vertical-axis wind turbine can be applied to the preliminary design of turbine output curve based on the wind characteristics at the proposed site by controlling its aerodynamic performance given as a priori.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.7
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• pp.709-716
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• 2013

A fan filter unit (FFU) is a device which supplies clean air from the ceiling in a clean room. With an increase in its size, velocity variation occurs within the exhaust plane and this damage the product quality or productivity. Hence, a guide vane is installed inside the device to enhance the velocity uniformity. Because the vane reduces the flow rate for a given pumping power, an optimum design is required to achieve velocity uniformity while minimizing the flow rate reduction at the same time. To find a geometry that satisfies these requirements, a series of numerical simulations has been conducted while changing the angle and length of the guide vanes. By changing the geometry of the side guide vane, the velocity uniformity increased by 3.7% and the flow rate decreased by 1.5%. For the center guide vane, the velocity uniformity increased by 2.9% and the flow rate decreased by 0.7%.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2491-2509
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• 2022

As an important device in the nuclear island, the nuclear coolant pump can continuously provide power for medium circulation. The vane is one of the stationary parts in the nuclear coolant pump, which is installed between the impeller and the casing. The shape of the vane plays a significant role in the pump's overall performance and stability which are the important indicators during the safety serve process. Hence, the bionic concept is firstly applied into the design process of the vane to improve the performance of the nuclear coolant pump. Taking the scaled high-performance hydraulic model (on a scale of 1:2.5) of the coolant pump as the reference, a united bionic design approach is proposed for the unique structure of the guide vane of the nuclear coolant pump. Then, a new optimization design platform is established to output the optimal bionic vane. Finally, the comparative results and the corresponding mechanism are analyzed. The conclusions can be gotten as: (1) four parameters are introduced to configure the shape of the bionic blade, the significance of each parameter is herein demonstrated; (2) the optimal bionic vane is successfully obtained by the optimization design platform, the efficiency performance and the head performance of which can be improved by 1.6% and 1.27% respectively; (3) when compared to the original vane, the optimized bionic vane can improve the inner flow characteristics, namely, it can reduce the flow loss and decrease the pressure pulsation amplitude; (4) through the mechanism analysis, it can be found out that the bionic structure can induce the spanwise velocity and the vortices, which can reduce drag and suppress the boundary layer separation.