A Methodology for the Assessment of Underground Railway-Induced Vibrations Based on Radiated Energy Flow Computed by Means of a 2.5D FEM-BEM Approach

Author(s):  
Dhananjay Ghangale ◽  
Robert Arcos ◽  
Arnau Clot ◽  
Jordi Romeu
2020 ◽  
Vol 101 ◽  
pp. 103392 ◽  
Author(s):  
Dhananjay Ghangale ◽  
Robert Arcos ◽  
Arnau Clot ◽  
Julen Cayero ◽  
Jordi Romeu

1970 ◽  
Vol 48 (7) ◽  
pp. 873-878 ◽  
Author(s):  
T. Kojima ◽  
K. Itakura

The problem of radiation from an electric dipole placed in a moving isotropic plasma has been studied by Lee and Papas for a special case where the velocity of the plasma is relatively small compared with the light velocity in vacuum. In this paper, we consider a radiation problem for a more general case where no restriction is imposed on the magnitude of the velocity of the plasma, and for a case where the source of radiation is assumed to be a magnetic line source.We investigate theoretically the effects of the movement of the plasma on the far-zone radiated electromagnetic fields and on the radiation pattern. The results show that the Poynting vector has a circumferential component, and therefore the direction of radiated-energy flow deviates from the radial direction, and it depends on the magnitude of the velocity of the plasma and on the angle between the position vector of an observer and the velocity vector of the plasma. Some numerical examples of its deviation and of the radiation pattern are illustrated.


1999 ◽  
Author(s):  
Ed O'Keefe ◽  
Matt Berge

2020 ◽  
Vol 67 (4) ◽  
pp. 305
Author(s):  
Hong Fu ◽  
Huan Zhang ◽  
Liang He ◽  
Yongcui Sha ◽  
Kangshun Zhao ◽  
...  

2016 ◽  
pp. 514-516
Author(s):  
Martin Bruhns

The massecuite circulates in a loop within the evaporating crystallizing vessel. The massecuite flows upwards through the heating tubes. In the room above the calandria the massecuite flow changes its direction to radial inwards and then to vertical downwards. An impeller in the central tube forces the circulation. Below the calandria the main direction of flow is radially outwards until threads of the massecuite stream enter the heating tubes in upwards direction. Within the tubes heat is transferred to the massecuite. At low temperature differences between heating steam and massecuite and higher levels of the massecuite in the crystallizer vapor bubbles are not found in the tubes. Vapor bubbles can be formed at a massecuite level in the crystallizer where the temperature of the massecuite is higher than the local boiling temperature of water, which depends on the local pressure (including the static pressure of the massecuite at this point) and the boiling point elevation of the mother liquor. The surface tension of the liquid is a resistance against the bubble formation, which has to be overcome by the local superheating i.e. the part of the enthalpy of the massecuite exceeding the local boiling temperature. The formation and the flow of the bubbles change the density of the massecuite/bubbles mixture and has an influence on the massecuite flow. The formation of a vapour bubble is connected with a local drop of the massecuite temperature which changes the local supersaturation. Today the heat transfer into the magma is quite well known but the process of bubble formation is quite unknown. Some basic considerations about the formation of bubbles and its influence on local supersaturation based on calculation of heat and mass balances and models of bubble formation are be given and discussed. Experiments for basic investigations are proposed.


2013 ◽  
Vol 20 (10) ◽  
pp. 1388-1393
Author(s):  
Bi JIANG ◽  
Fa-Qi WU ◽  
Xi-Hui WU ◽  
Ming LI ◽  
Xiao-Gang TONG

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