Piston effect under the Channel

1997 ◽  
Author(s):  
W.M.S. Bradbury
Keyword(s):  
Piston Effect

Numerical Study on Fire Smoke Movement in Elevator Shafts Under Piston Effect

2012 ◽  
Vol 22 (4) ◽  
pp. 387-405 ◽  
Author(s):  
Yanqiu Chen ◽  
Lizhong Yang ◽  
Taolin Zhang
Keyword(s):  
Numerical Study ◽  
Smoke Movement ◽  
Piston Effect ◽  
Fire Smoke

scholarly journals Subway platform air quality: Assessing the influences of tunnel ventilation, train piston effect and station design

2014 ◽  
Vol 92 ◽  
pp. 461-468 ◽  
Author(s):  
T. Moreno ◽  
N. Pérez ◽  
C. Reche ◽  
V. Martins ◽  
E. de Miguel ◽  
...  
Keyword(s):  
Air Quality ◽  
Piston Effect ◽  
Tunnel Ventilation

Numerical Analysis of Elevator Piston Effect on Building Airflow for an Air-Conditioned High-Rise Building in Winter

2014 ◽  
Vol 1008-1009 ◽  
pp. 1068-1074 ◽  
Author(s):  
Yan Wang ◽  
Yan Ling Guan ◽  
Yuan Sheng Yin
Keyword(s):  
Pressure Distribution ◽  
Upward Movement ◽  
Piston Effect ◽  
Air Conditioning System ◽  
Security Issues ◽  
High Rise ◽  
Computational Fluid Dynamics Cfd ◽  
Elevator Door ◽  
Mesh Technique ◽  
Storey Building

A model of a 24-storey building (94.5m high) with air-conditioning system was developed to analyze the elevator piston effect on building airflow by dynamic mesh technique of computational fluid dynamics (CFD). The results of the pressure distribution and airflow paths show that with the upward movement of elevator cabs, due to the elevator piston effect, changes in the pressure distribution and airflow paths occur in all the building; the pressure difference across the elevator door is enlarged, which is likely to cause some security issues; but the air exfiltration rate is hardly affected.

Magneto-Optic Piston Effect

1999 ◽  
Vol 83 (4) ◽  
pp. 710-713 ◽  
Author(s):  
S. Dattagupta ◽  
R. Ghosh ◽  
J. Singh
Keyword(s):  
Piston Effect ◽  
Magneto Optic

Two typical time scales of the piston effect

2005 ◽  
Vol 71 (6) ◽  
Author(s):  
Pierre Carlès ◽  
Kokou Dadzie
Keyword(s):  
Time Scales ◽  
Piston Effect ◽  
Typical Time

scholarly journals Numerical simulation of pollutant dispersion in urban roadway tunnels

2017 ◽  
Vol 9 (1) ◽  
pp. 26-31 ◽  
Author(s):  
Jingliang Dong ◽  
Yao Tao ◽  
Yimin Xiao ◽  
Jiyuan Tu
Keyword(s):  
Air Quality ◽  
Traffic Congestion ◽  
Pollutant Dispersion ◽  
Piston Effect ◽  
Traffic Jam ◽  
Traffic Conditions ◽  
Toxic Emissions ◽  
Driving Speed ◽  
Moving Vehicles ◽  
Short Tunnel

Vehicular toxic emissions can easily contaminate the air quality of the enclosed tunnel environment, especially during rush hours with traffic jam events or low vehicle speeds, which poses serious health hazards to road utilizers. The piston effect generated by moving vehicles was normally considered adequate to discharge vitiated air out of short tunnel based on a typical driving speed. However, complex traffic conditions may yield unexpected consequences on in-tunnel air quality levels. This study numerically investigated the CO2 concentration to identify the in-tunnel pollutant dispersion under three traffic conditions including severe traffic congestion and traffic flow with low vehicle speeds. Fan conditions were considered to model the influence of mechanical winds on pollutant dispersion and comparison with vehicular piston effect was also performed. The results revealed elevated pollutant concentration regions were found at the vicinity of near-ground region and tunnel downstream. The vehicular piston effect can sufficiently remove the in-tunnel vehicular emissions when vehicles travel at relatively higher speed. However, pollutant accumulation occurs when vehicles are idling or moving at slow speed. Compared with traffic piston effect at high travelling speed, the mechanical ventilation of ceiling mounted fans only generate a limited contribution to the removal of emissions.

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