Study on Performance and Internal Flow of Cross-Flow Wind Turbine

2003 ◽  
Author(s):  
Kazuki Takeuchi ◽  
Junichiro Fukutomi ◽  
Hidetoshi Kodani ◽  
Hironori Horiguchi
Keyword(s):  
Wind Turbine ◽  
Pressure Difference ◽  
Main Part ◽  
Cross Flow ◽  
Internal Flow ◽  
Power Coefficient ◽  
Construction Costs ◽  
Outer Flow ◽  
Output Coefficient ◽  
The Cross

The wind turbine has become more popular in recent years, but on the other hand, the developments of small wind-turbine have been legging behind. Because, the energy density of wind is small, since the efficiency of the main part of a wind turbine is very low. The construction costs become comparatively high-priced. Then, the main part of this subject is to show that, by collecting and sucking out more winds, a wind turbine is made to pass many winds and the new cross-flow wind turbine that increases an output coefficient is proposed. The cross-flow wind turbine has high torque and low speed characteristics and the structure are very simple. So, it can be used in a large wind velocity region. However, even if the power coefficient is high, it is about 10%. The purpose of this paper is to show how we can improve the power coefficient by applying a casing, which has a nozzle and a diffuser. This research was made to clear up fundamental characteristics of the interaction between outer flow and inner flow. Three kinds of cross-flow wind turbines were designed. The nozzle and diffuser have been designed suitable for the performance of wind turbine. The flow simulations by CFD have been carried out for various types of casings at 20 m/s with Fluent Ver5.0. All Wind tunnel experiments were performed at 20m/s. The case of casing 2, which have plate arranged near the separation point of cylinder, also experimented. The rotor that is settled in the casing 1 shows a larger power coefficient than the case without a casing. The casing of the cross-flow turbine makes a pressure difference between inflow and outflow. The pressure difference increases the mass flow rate. Therefore much more wind passes through into the cross-flow turbine. In this experiment, the power coefficient increased 1.5 times in the case with casing. A still higher output coefficient could be obtained in the case where it is shown by the casing 2.

Performance and Flow Condition of Cross-Flow Wind Turbine With a Symmetrical Casing

2011 ◽  
Author(s):  
Junichiro Fukutomi ◽  
Toru Shigemitsu ◽  
Masaaki Toyohara
Keyword(s):  
Wind Turbine ◽  
Flow Condition ◽  
Cross Flow ◽  
Internal Flow ◽  
Low Noise ◽  
Maximum Power ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Urban District ◽  
The Cross

A cross-flow wind turbine has a high torque coefficient at a low tip speed ratio. Therefore, it is a good candidate for use as a self-starting turbine. Furthermore, it has low noise and excellent stability; therefore, it has attracted attention from the viewpoint of applications as a small wind turbine for an urban district. However, its maximum power coefficient is extremely low (10%) as compared to that of other small wind turbines. In order to improve the performance and the flow condition of the cross-flow rotor, symmetrical casing with a nozzle and a diffuser are proposed and experimental research with the symmetrical casing is conducted. The maximum power coefficient is obtained as Cpmax = 0.17 for casing and Cpmax = 0.098 in the case without the casing. In the present study, power characteristics of the cross-flow rotor and those of the symmetrical casing with the nozzle and the diffuser are investigated. Then, the performance and internal flow patterns of the cross-flow wind turbine with the symmetrical casings are clarified. After that, the effect of the side boards set on the symmetrical casing is discussed on the basis of the analysis results.

Study on Performance and Flow Condition of a Cross-Flow Wind Turbine With a Symmetrical Casing

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
Junichiro Fukutomi ◽  
Toru Shigemitsu ◽  
Hiroki Daito
Keyword(s):  
Wind Turbine ◽  
Rotational Speed ◽  
Flow Condition ◽  
Cross Flow ◽  
Low Noise ◽  
Maximum Power ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Tip Speed Ratio ◽  
The Cross

A cross-flow wind turbine has a high torque coefficient at a low tip speed ratio. Therefore, it is a good candidate for use as a self-starting turbine. Furthermore, it has low noise and excellent stability; therefore, it has attracted attention from the viewpoint of applications as a small wind turbine for an urban district. However, its maximum power coefficient is extremely low (10%) as compared to that of other small wind turbines. Prevailing winds in two directions often blow in urban and coastal regions. Therefore, in order to improve the performance and the flow condition of the cross-flow rotor, a casing suitable for this sort of prevailing wind conditions is designed in this research and the effect of the casing is investigated by experimental and numerical analysis. In the experiment, a wind tunnel with a square discharge is used and main flow velocity is set as 20 m/s. A torque meter, a rotational speed pickup, and a motor are assembled with the same axis as the test wind turbine and the tip speed ratio is changeable by a rotational speed controller. The casing is set around the cross-flow rotor and flow distribution at the rotor inlet and the outlet is measured by a one-hole pitot tube. The maximum power coefficient is obtained as Cpmax = 0.19 with the casing, however Cpmax = 0.098 without the casing. It is clear that the inlet and the outlet flow condition is improved by the casing. In the present paper, in order to improve the performance of a cross-flow wind turbine, a symmetrical casing suitable for prevailing winds in two directions is proposed. Then, the performance and the internal flow condition of the cross-flow wind turbine with the casing are clarified. Furthermore, the influence of the symmetrical casing on performance is discussed and the relation between the flow condition and performance is considered.

Study on Performance and Flow Condition of Cross-Flow Wind Turbine With a Symmetrical Casing

2009 ◽  
Author(s):  
Junichiro Fukutomi ◽  
Toru Shigemitsu ◽  
Hiroki Daito
Keyword(s):  
Wind Turbine ◽  
Rotational Speed ◽  
Flow Condition ◽  
Cross Flow ◽  
Low Noise ◽  
Maximum Power ◽  
Power Coefficient ◽  
Urban Region ◽  
Prevailing Wind ◽  
The Cross

Wind turbine has been attracted as the technology for clean and renewable energy and many kinds of the researches and the developments are performed. Cross-flow wind turbine has a characteristic of good self-starting, low noise and high stability. Therefore, it is expected as the small-sized wind turbine for urban district. But the maximum power coefficient of the cross-flow wind turbine is extremely low as 10%. Wind in an urban region and a coastal place has a prevailing wind of two directions to occur in a specific condition frequently. Then, a casing suitable for this prevailing wind was designed in this research and the effect of the casing was investigated by experimental and numerical analysis. In the experiment, a wind tunnel with a square discharge 500mm×500mm was used and main flow velocity was set as 20m/s to reduce the influence of measurement error on performance. A torque meter, a rotational speed pickup and a motor were assembled with the same axis at low position of a test wind turbine which was set vertically and rotational speed and tip speed ratio were changeable by a rotational speed controller. The casing was set around the cross-flow rotor and flow distribution at the rotor inlet and the outlet was measured by a one-hole pitot tube. The maximum power coefficient was obtained as Cpmax = 0.19 with the casing, however as Cpmax = 0.098 without the casing. And it was clarified that the inlet and the outlet flow condition was improved by the casing. In the present paper, in order to improve the performance of a cross-flow wind turbine, a symmetrical casing suitable for the prevailing wind of two directions is proposed. Then performance and internal flow condition of the cross-flow wind turbine with the casing is clarified. Furthermore, the influence of a symmetrical casing on performance is discussed and the relation between flow condition and performance is considered.

scholarly journals Attenuation of Cross-Flow Fan Noise Using Porous Stabilizers

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Huanxin Lai ◽  
Meng Wang ◽  
Chuye Yun ◽  
Jin Yao
Keyword(s):  
Cross Flow ◽  
Sound Radiation ◽  
Internal Flow ◽  
Considerable Effect ◽  
Front Wall ◽  
Performance Curve ◽  
Fan Noise ◽  
Aerodynamic Performances ◽  
The Cross ◽  
Cross Flow Fan

This paper presents a qualitative analysis of controlling the cross-flow fan noise by using porous stabilizers. The stabilizer was originally a folded plate. It is changed into a porous structure which has a plenum chamber and vent holes on the front wall. In order to investigate the influences of using the porous stabilizers, experiments are carried out to measure the cross-flow fan aerodynamic performances and sound radiation. Meanwhile, the internal flow field of the fan is numerically simulated. The results show that the porous stabilizers have not produced considerable effect on the cross-flow fan's performance curve, but the noise radiated from the fan is strongly affected. This indicates the feasibility of controlling the cross-flow fan noise by using the porous stabilizers with selected porosity.

Internal Flow Characteristics of Cross-Flow Hydraulic Turbine With the Variation of Nozzle Shape

2007 ◽  
Author(s):  
Young-Do Choi ◽  
Jea-Ik Lim ◽  
You-Taek Kim ◽  
Young-Ho Lee
Keyword(s):  
Flow Characteristics ◽  
Cross Flow ◽  
Internal Flow ◽  
Close Relation ◽  
Hydraulic Turbine ◽  
Impulse Turbine ◽  
Runner Blade ◽  
Turbine Performance ◽  
Nozzle Shape ◽  
The Cross

The purpose of this study is to examine the optimum configuration of nozzle shape to further optimize the cross-flow hydraulic turbine structure and improve the performance. The results show that CFD analysis for the cross-flow turbine can be adopted as a useful method to examine the internal flow and turbine performance in detail. Pressure on the runner blade in Stage 1 and velocity at nozzle outlet have close relation to the turbine performance. The performance characteristics of cross-flow turbine have both impulse turbine and reaction turbine simultaneously.

scholarly journals Studi simulasi penggunaan airfoil naca 6412 sebagai sudu pada turbin angin crossflow melalui pemodelan CFD 2 dimensi

2018 ◽  
Vol 13 (1) ◽  
pp. 28
Author(s):  
Muhammad Ivan Fadhil Hendrawan ◽  
Dominicus Danardono ◽  
Syamsul Hadi
Keyword(s):  
Wind Turbine ◽  
Constant Velocity ◽  
Cross Flow ◽  
Vertical Axis ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Vertical Axis Wind Turbine ◽  
Ansys Fluent ◽  
Tip Speed Ratio ◽  
Blade Number

AbstractThe simulation aimed to understand the effect of the angle of blade number and blade number of vertical axis wind turbine with cross flow runner to enhance the performance of wind turbine. The turbine had 20, 22, and 24 number of blades. Simulation was done in 2D analysis using ANSYS-Fluent. Tip speed ratio was varied in range of 0,1-0,5 with constant velocity inlet 2 m/s. The effect of blade numbers to torque and power coefficient were analyzed and compared. It had been found that the best power coefficient were 0,5 at tip speed ratio 0,3.

Performance of a Cross-Flow Wind Turbine Located Above a Windbreak Fence

2015 ◽  
Author(s):  
Haruka Sakai ◽  
Takahiro Kiwata ◽  
Hiroaki Nakata ◽  
Takaaki Kono ◽  
Hiroko Furumichi ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Flow Analysis ◽  
Cross Flow ◽  
Velocity Fields ◽  
Power Coefficient ◽  
Two Dimensional ◽  
Ansys Fluent ◽  
The Relationship ◽  
Rotational Direction ◽  
Porous Fence

The performance of a cross-flow wind turbine located above a windbreak fence (snowbreak fence) and the associated velocity fields were investigated through wind tunnel tests. The effects of the amount of vertical clearance between the wind turbine and the fence, the percentage of the fence area that is nonporous, and the rotational direction of the turbine were examined. In addition, a two-dimensional numerical flow analysis of the cross-flow wind turbine above the fence was performed using the CFD software ANSYS FLUENT 13.0. The fence and wind turbine models were built to a scale of 1:5; the porous fence model had a height of h = 500 mm, and the diameter of the wind turbine was 80 mm. It was found that the relationship between the inflow velocity into the clearance gap and the rotational direction of the turbine affects the power coefficient of the turbine.

Single- and Two-Phase Diversion Cross-Flows Between Triangle Tight Lattice Rod Bundle Subchannels: Data on Flow Resistance and Interfacial Friction Coefficients for the Cross-Flow

2006 ◽  
Author(s):  
Tatsuya Higuchi ◽  
Akimaro Kawahara ◽  
Michio Sadatomi ◽  
Hiroyuki Kudo
Keyword(s):  
Friction Coefficient ◽  
Pressure Difference ◽  
Flow Resistance ◽  
Cross Flow ◽  
Resistance Coefficient ◽  
Interfacial Friction ◽  
Two Phase ◽  
Rod Bundle ◽  
The Cross ◽  
Tight Lattice

Single- and two-phase diversion cross-flows arising from the pressure difference between tight lattice subchannels are our concern in this study. In order to obtain a correlation of the diversion cross-flow, we conducted adiabatic experiments using a vertical multiple-channel with two subchannels simplifying the triangle tight lattice rod bundle for air-water flows at room temperature and atmospheric pressure. In the experiments, data were obtained on the axial variations in the pressure difference between the subchannels, the ratio of flow rate in one subchannel to the whole channel, the void fraction in each subchannel for slug-churn and annular flows in two-phase flow case. These data were analyzed by use of a lateral momentum equation based on a two-fluid model to determine both the cross-flow resistance coefficient between liquid phase and channel wall and the gas-liquid interfacial friction coefficient. The resulting coefficients have been correlated in a way similar to that developed for square lattice subchannel case by Kano et al. (2002); the cross-flow resistance coefficient data can be well correlated with a ratio of the lateral velocity due to the cross-flow to the axial one irrespective of single- and two-phase flows; the interfacial friction coefficient data were well correlated with a Reynolds number, which is based on the relative velocity between gas and liquid cross-flows as the characteristic velocity.

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