D504 SWISSMETRO-Project Development Status

Cassat, A.; Bourquin, Vincent; Mossi, M.; Badoux, Marc; Vernez, D.; Jufer, Marcel; Macabrey, Nicolas; Rossel, P.

doi:10.1299/jsmestech.2003.453

Cited by 13 publications

(8 citation statements)

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“…Although numerous proposals have been made for conceptual designs of SSTT systems, they are yet to be realised, primarily because of the enormous construction cost. Because of this problem, the most recent SSTT research projects (Cassat et al, 2003;Korea Railroad Research Institute, 2009;Lee et al, 2008) have aimed at a more practical train speed of 500-700 km/h, by reducing the air pressure inside the tubes to as low as 0 . 1 atm (equivalent to approximately 10 kPa).…”

Section: Notationmentioning

confidence: 99%

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Performance evaluation of airtightness in concrete tube structures for super-speed train systems

Park

Kim

Nam

et al. 2013

Magazine of Concrete Research

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A super-speed tube train (SSTT) system is a conceptual alternative transportation system where trains could operate with a practical speed as high as 700 km/h in a vacuum tunnel, which minimises air resistance. This paper presents the results of a preliminary study involving an airtightness performance evaluation of a concrete vacuum tube structure for an SSTT. A formula for determining the flow rate of the air movement caused by the pressure difference inside and outside the tube structure is derived on the basis of Darcy's law. A material test is performed to measure the air permeability of concrete with various compressive strengths. A large-scale experimental study is then conducted for concrete tube structures with various joint configurations to investigate the suitability of concrete tube structures for an SSTT system. The results show that, as expected, a structure with more joints or bonds tends to be less airtight. A sensitivity study shows that the system's airtightness performance level increases with an increase in either the diameter or thickness of the tube. Moreover, an increase in the diameter or thickness of the tube enhances the effectiveness of any approach used for improving the airtightness of the system.

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Section: Notationmentioning

confidence: 99%

“…According to the conceptual design of the SSTT system (Cassat et al, 2003;Korea Railroad Research Institute, 2009;Lee et al, 2008), the intended internal pressure of the tube is 0 . 1 atm, or 10 kPa.…”

Section: Derivation Of Analytical Modelling For Air Intrusion In Closmentioning

confidence: 99%

Performance evaluation of airtightness in concrete tube structures for super-speed train systems

Park

Kim

Nam

et al. 2013

Magazine of Concrete Research

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“…Swissmetro is a MAGLEV Project (8) (9) , designed for speeds up to 500 km/h in two tunnels of 5 m inside diameter, under a partial vacuum of 8000 Pa. Thus the aerodynamic drag force is reduced.…”

Section: Swissmetro-new Variantsmentioning

confidence: 99%

Polarized Linear Motor Combined With Levitation Actuators Working in a Partial Vacuum Environment-Application to Swissmetro

Cassat

Espanet

Bourquin³

et al. 2006

IEEJ Trans. IA

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Swissmetro is a MAGLEV Project, designed for speeds up to 500 km/h in two tunnels of 5 m inside diameter, under a partial vacuum of 8000 Pa. Thus the aerodynamic drag force is reduced.In this paper, the authors investigate new possibilities to combine both the propulsion and the levitation. The new proposed variant use a linear synchronous motor, as shown in Fig. 1, with a long stator, fixed with the tunnel. The magnetic way, onboard of the vehicle, supports the excitation created by NdFeB permanent magnets (PM) and the inductor windings for the levitation control. Synchronous linear motors imply a short pole pitch of 231 mm. The maximum synchronous frequency is 300 Hz, corresponding to a speed of 500 km/h. The winding has a fractional number of slots per pole and per phase and a coil opening of one slot.The motor design is based on three numerical models: (1) a lumped magnetic scheme for a first order design; (2) 2D FEM simulations confirm the chosen configurations; (3) the 3D FEM simulations permit to determine the aerodynamics of the vehicle in the tunnel and to calculate the heat transfer of the levitation inductors mounted on the vehicle.The total mechanical power is 6 MW. The magnetic ways are distributed on both vehicle sides, in the nose, the four vehicle cells and the trail. Consequently, each active part of the motors sees a twelveth of the mechanical power. The PM pole pitches are large so that the PM losses are a design issue requiring a deep investigation. Table 1 gives the losses for various configurations, showing that a stator tooth shoe and a segmentation of the PM pole are necessary. For a long stator, only the stator section in front of the vehicle is energized. For one direction, the frequency of vehicles per hour is one each 6 min and the speed is v = 139 m/s. Then, for a stator section length of 5000 m, the duty cycle, which equals to 0.01, is very low, so that the heat dissipation at the level of the stator is not an issue. Table 2 gives the power balance for one vehicle. The efficiency decreases with the increase of the length of the stator sections. An optimum must be defined between the stator investment costs, related to the current density and to the operational costs, related to the consumption of energy.The additional inductor produces the necessary force complement to control the leviation of the vehicle. Figure 2 shows the spatial repartition of the attraction force and the evolution of the Fig. 1. Swissmetro, Variant using combined propulsion with levitation force versus the inductor compensation MMF. As the pressure in the tunnel is reduced, the capability of the flow to transfer heat through convection is questioned. 3D computations enable an investigation of the spatial pressure, the air flow speed and the temperature. For the new proposed variant (Figure 3, Table 3), the distribution of the power dissipated by the magnetic way on the complete vehicle length provides better cooling. The lineic distribution of the heat losses is a solution for the heating problem in a partial v...

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“…The super-speed tube transport (SSTT) system, which helps to minimize the air resistance of vehicles by keeping the pressure inside the tunnel or tube structure much lower than the atmospheric pressure (Figure 1), is drawing attention as a next-generation transportation system owing to its high efficiency and environmental friendliness [1][2][3][4]. In addition to general design requirements for the stiffness and strength with respect to the design loads, such as vehicle loads, the tube structure of an SSTT system should have the capability of maintaining the internal air pressure level, which is initially lowered.…”

Section: Introductionmentioning

confidence: 99%

Analytical Model for Air Flow into Cracked Concrete Structures for Super-Speed Tube Transport Systems

Devkota

Park

2019

Infrastructures

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The super-speed tube transport (SSTT) system, which enables high-speed transportation in a partially vacuumed tube by minimizing the air resistance, is drawing attention as a next-generation transportation system. To evaluate the applicability of concrete as a material for the system, the effect of cracks on the airtightness of the system needs to be considered. This study aims to establish an analytical relationship between the cracks induced on a concrete tube structure and the system airtightness. An analytical model for the leakage rate through the concrete cracks is first applied to establish a differential equation, which can help determine the air flow rate into the concrete tube structure through the cracks. A mathematical formula for predicting the internal pressure changes over time in the concrete tube structure is then derived. The effect of crack development on the system airtightness is assessed through parametric analysis and a crack index for describing the extent of crack development is proposed by investigating the correlation with the system airtightness. Finally, assuming that the cracks due to external loadings are closely related to the displacement, the correlation between displacements and the airtightness of concrete tube structures is demonstrated through a set of experimental tests. As a result, the necessity of crack analysis for evaluation of the airtightness performance is emphasized.

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D504 SWISSMETRO-Project Development Status

Cited by 13 publications

References 0 publications

Performance evaluation of airtightness in concrete tube structures for super-speed train systems

Performance evaluation of airtightness in concrete tube structures for super-speed train systems

Polarized Linear Motor Combined With Levitation Actuators Working in a Partial Vacuum Environment-Application to Swissmetro

Analytical Model for Air Flow into Cracked Concrete Structures for Super-Speed Tube Transport Systems

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