Improved design of Savonius rotor for green energy production from moving Singapore metropolitan rapid transit train inside tunnel
01 Apr 2019-Vol. 233, Iss: 7, pp 2426-2441
TL;DR: In this article, the authors proposed that non-renewable fossil fuels are finite resources that will ultimately deplete in near future, and that humans harvest a morsel of renewable wind energy but not all of it.
Abstract: Nonrenewable fossil fuels are finite resources that will ultimately deplete in near future. Nature sheds colossal amount of renewable wind energy but humans harvest a morsel. Taking this into accou...
Citations
More filters
[...]
TL;DR: A new type of self-powered system for WSN nodes in tunnels to solve the power supply problem in subway tunnel safety monitoring systems and can provide continuous and stable power for W SN node systems in subway tunnels is presented.
Abstract: With the rapid development of urban rail transit, the safety maintenance of subway tunnels has attracted attention in various countries. Tunnel safety monitoring systems are used to ensure the safety of subway operation. This paper presents a new type of self-powered system for WSN nodes in tunnels to solve the power supply problem in subway tunnel safety monitoring systems. This new self-powered system collects wind energy in subway tunnels and converts it into electrical energy for storage and utilization. The system is composed of three parts: electromagnetic wind energy acquisition module, piezoelectric wind energy acquisition module, and power generation energy storage module. The electromagnetic wind energy acquisition module uses the principle of electromagnetic induction to convert wind energy into electrical energy. The piezoelectric wind energy acquisition module uses piezoelectric patches to convert wind energy into electrical energy. The power generation energy storage module converts the collected AC power into DC power, stores it in the supercapacitor, and supplies power to the WSN nodes. Experimental data shows that the energy output power of the system at a wind speed of 7 m/s is 59.31 mW. The Chengdu subway line 2 was selected for case study; the energy consumed by WSN nodes accounts for 49.4%–59.8% of the energy collected by the system. The proposed system can provide continuous and stable power for WSN node systems in subway tunnels.
2 citations
[...]
TL;DR: In this paper , the authors proposed a novel blade configuration, made with a multicurve profile, to further maximize the advanced benefits and the performance of a Savonius turbine for energy harvesting applications.
Abstract: ABSTRACT This study proposes a novel blade configuration, made with a multicurve profile, to further maximize the advanced benefits and the performance of a Savonius turbine for energy harvesting applications. The advantages of the presently designed blade are proved by a detailed analysis of the flow mechanism and the performance through a sequence of two-dimensional (2D) unsteady computational fluid dynamics simulation. The remarkable finding states that the main blade section with a length ratio of 0.9 combined with an elliptical auxiliary section effectively enhances the positive wind flow phenomena around the blade, especially for the returning position, which either smooths the flow or reduces the pressure on the blade’s convex side. As a result, greater torque is obtained by the present configuration, responding to the improvement of the power generation to 0.24 – about 5.5% at the low TSR = 0.8 and up to 0.28 - about 185% at the high TSR = 1.5 over the conventional configurations. The effectiveness of the presently designed blade is further proved with more than 20% improvement in self-staring speed through six degrees of freedom analysis. The results above state a high potential application of the turbine with the presently designed blade for renewable energy applications and for supporting vulnerable communities without access to electricity.
1 citations
Patent•
[...]
18 Nov 2010
TL;DR: In this article, an arcuate structure extending over a highway and a cover over the structure to create an enclosure is proposed to protect the highway and users of the highway from rain, snow and sun.
Abstract: A structure for sheltering and optimizing highway systems includes an arcuate structure extending over a highway and a cover over the structure to create an enclosure. The enclosure protects the highway and users of the highway from rain, snow and sun while the surrounding scenery remains visible to drivers. A number of different additions optimize use of the highway. For example, a plurality of solar panels are layered on the cover and wind turbines are used to create usable energy, an air current generation system reduces wind resistance on vehicles to increase gas mileage, and an elevated rail system transports many persons great distances along the highway.
1 citations
[...]
TL;DR: In this article, the effect of uniform speed on the transient aerodynamic behaviors in a subway tunnel was analyzed, and the results show that there are differences in aerodynamic behavior in subway tunnel when a train is in the acceleration and deceleration stages.
Abstract: Aerodynamic effects, including slipstream, piston wind, drag, and pressure wave, in the tunnel caused by a metro train running between two adjacent platforms were simulated using a metro train model with six cars, an RNG ᴋ–e turbulence model, and the sliding mesh technology, and they were verified through some full-scale tests and scale model experiments. Theoretical analysis and computational fluid dynamics (CFD) were used to investigate the formation and spatial–temporal distribution characteristics of the wind environment in a tunnel. The effect of uniform speed on the transient aerodynamic behaviors in the tunnel was analyzed. The results show that there are differences in aerodynamic behaviors in a subway tunnel when a train is in the acceleration and deceleration stages. Piston wind is a kind of high-quality wind resource, and it is better to arrange the wind turbines close to the destination platform. Some results can provide theoretical support for the recovery of wind energy resources and the layout of fans in the tunnel. Further, they can increase the development and utilization of urban underground space.
[...]
TL;DR: In this paper, a computer-oriented fluid-solid integrate simulation of wind turbine propelled by train-induced wind is performed by executing all physically realistic boundary conditions, and the results were validated against benchmark experimental study.
Abstract: A novel and strategic green energy production method that utilizes relative wind generated from moving vehicles is presented. A speeding train generates an enormous wake of wind around it, which stocks a substantial amount of kinetic energy. In this study, this freely accessible wind power is harvested by installing a modified savonius wind turbine within the slipstream region of the train. A computer-oriented fluid-solid integrate simulation of wind turbine propelled by train-induced wind is performed by executing all physically realistic boundary conditions. The numerical study is based on open-source CFD toolbox openfoam, and the results were validated against benchmark experimental study. Parametric sensitivity analysis such as optimal turbine performance within the slipstream regime, torque prediction from express trains, two opposite crossing trains, tunnel condition, and turbine wind turbine clusters arrangement has been reported. This study enhances the understanding of the power generation by the turbine from the train slipstream which is not reported in any open literature as far as the authors’ present knowledge goes.
References
More filters
[...]
TL;DR: In this article, the authors numerically explore the non-linear two-dimensional unsteady flow over a conventional Savonius rotor and a Bach-type rotor, and develop a simulation method for predicting their aerodynamic performance.
Abstract: The Savonius vertical axis wind turbine is simple in structure, has good starting characteristics, relatively low operating speeds, and an ability to accept wind from any direction, although it has a lower efficiency than some other vertical axis wind turbines. So far a number of experimental investigations have been carried out to study the performance of the Savonius rotor; however, there is a lack of detailed descriptions of the flow field for different types of Savonius rotors. The aim of this paper is to numerically explore the non-linear two-dimensional unsteady flow over a conventional Savonius-type rotor and a Bach-type rotor, and develop a simulation method for predicting their aerodynamic performance. The simulations are performed using Star-CCM+. The motion of the blades is solved by using a moving mesh. A comparative study of the two types of rotors was carried out, and numerical simulation results were compared with experimental data. The Bach-type rotor is demonstrated to have better performance for torque and power coefficient than the conventional Savonius-type rotor. A discussion of the causes of these differences is presented that is based on a detailed study of the respective flow field characteristics, including the behavior of moment coefficients, velocity vectors and pressure distribution. A simulation method for further study of new blades shapes is suggested.
101 citations
[...]
TL;DR: In this paper, a numerical model is used to simulate the starting of an H-rotor Darrieus turbine under steady wind conditions, demonstrating unaided start-up of a three-bladed turbine in a steady wind.
Abstract: As the demand for renewable energy grows, the use of small wind turbines becomes increasingly attractive. Turbines using vertical-axis geometries are particularly suited to the urban environment by virtue of their operation being independent of wind direction. However, such designs have received much less attention than the more common ‘propeller type’ designs and the understanding of some aspects of their operation remains weak. This is particularly true of their starting characteristics. Indeed, some authors maintain that they cannot start without external assistance.In this investigation a numerical model is used to simulate the starting of an H-rotor Darrieus turbine under steady wind conditions. Experimental wind-tunnel data for a small prototype is presented, demonstrating unaided start-up of a three-bladed Darrieus in a steady wind. Discrepancy between the modelled and experimental results demonstrate that modelling remains constrained by the quality of data on aerofoil characteristics.
97 citations
[...]
TL;DR: In this article, the slipstream and wake flow of a simplified five-coach ICE2-shape train running in two different environments; in open air and when passing a platform, were obtained using large-eddy simulation (LES).
Abstract: High-speed trains push air to the front, sides and over the top to form a train slipstream. The extension of the slipstream to the side, top and wake flow depends on train speed, train shape, ambient conditions and the environment in which the train operates. In this paper, the slipstream and wake flow of a 1/20th scale model of a simplified five-coach ICE2-shape train running in two different environments; in open air and when passing a platform, were obtained using large-eddy simulation (LES). The flow Reynolds number was taken to be 300,000; based on the speed and height of the train. The effect of the platform height on the train slipstream was investigated by performing simulations on a platform of different heights: 20, 60, 90 cm. To investigate the effect of mesh resolution on the results, two different computations were performed for the case of the flow around the train running in the open air using a different number of mesh nodes; a fine mesh consisting of 18,000,000 nodes and a coarse mesh con...
75 citations
[...]
TL;DR: In this article, the effects of acceleration and speed of the metro train, and of platform spacing, on the alternating pressure on the train and in the tunnel are studied, and the analysis of the impact of train acceleration, the pressure change inside a passenger train in a 1-s timespan was used to evaluate the comfort of passengers.
Abstract: As a fast and efficient short distance transportation means, the subway line has been built and expanded in an increasing number of cities. The pressure in the tunnel fluctuates significantly while metro trains pass. This kind of pressure may damage the equipment and workers in the tunnel. Considering that, the metro train does not have airtightness, and that pressure can spread inside the vehicle, passengers in the vehicle would be directly affected by the alternating aerodynamic pressure, which causes discomfort to passengers. This phenomenon is exacerbated at high speeds. Therefore, it is important to estimate the aerodynamic alternating pressure generated by the metro train in the tunnel before construction. In this study, the aerodynamic performance of a metro train running between two adjacent platforms in a tunnel was simulated by using FLUENT. In this work, the effects of acceleration and speed of the metro train, and of platform spacing, on the alternating pressure on the train and in the tunnel are studied. In the analysis of the impact of train acceleration, the pressure change inside a passenger train in a 1 s timespan was used to evaluate the comfort of passengers. Maximum and average ΔP (pressure changes in amplitude) shows an exponential relationship with a (acceleration), Vc (constant speed) and Lplatform (platform spacing), especially the ΔP measured on tunnel surface. The fluctuation of the train surface pressure is more intense than that of the tunnel. The Pmin (minimum pressure) on the train surface and in the tunnel is not affected by the acceleration of the train, but it is mainly related to the highest train speed in the tunnel. When the platform spacing is higher than 1500 m, Pmax, Pmin, and △P in the tunnel and on the train surface showed little change. These findings contribute not only to the design of the metro train and tunnel system, but also to the guidance of the metro train operation.
44 citations
[...]
TL;DR: In this article, the effect of blade fullness on the power of a two-bladed Savonius wind turbine was investigated using transient computational fluid dynamics (CFD) simulations based on the Reynolds Averaged Navier-Stokes equations with a renormalization group turbulent model.
Abstract: The Savonius wind turbine is a type of vertical axis wind turbine (VAWTs) that is simply composed of two or three arc-type blades which can generate power even under poor wind conditions. A modified Savonius wind turbine with novel blade shapes is introduced with the aim of increasing the power coefficient of the turbine. The effect of blade fullness, which is a main shape parameter of the blade, on the power production of a two-bladed Savonius wind turbine is investigated using transient computational fluid dynamics (CFD). Simulations are based on the Reynolds Averaged Navier-Stokes (RANS) equations with a renormalization group turbulent model. This numerical method is validated with existing experimental data and then utilized to quantify the performance of design variants. Results quantify the relationship between blade fullness and turbine performance with a blade fullness of 1 resulting in the highest coefficient of power, 0.2573. This power coefficient is 10.98% higher than a conventional Savonius turbine.
42 citations
Related Papers (5)
[...]
[...]
[...]