Comparison of subsonic and supersonic mixing mechanisms for the chemical oxygen-iodine laser (COIL) using computational fluid dynamic (CFD) simulations

1999 ◽  
Author(s):  
Timothy J. Madden ◽  
Gordon D. Hager ◽  
Alan I. Lampson ◽  
Peter G. Crowell
Keyword(s):  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Cfd Simulations ◽  
Iodine Laser ◽  
Chemical Oxygen Iodine Laser ◽  
Supersonic Mixing

Smoke Simulation in an Underground Train Station Using Computational Fluid Dynamic

2014 ◽  
Vol 663 ◽  
pp. 366-372 ◽  
Author(s):  
Zambri Harun ◽  
Muhammad Saiful bin Sahari ◽  
Taib Iskandar Mohamad
Keyword(s):  
Computational Fluid Dynamic ◽  
Fire Safety ◽  
Fluid Dynamic ◽  
Fire Department ◽  
Cfd Simulations ◽  
Train Station ◽  
Hazardous Gases ◽  
Design Software ◽  
Underground Station ◽  
Safety Systems

The design of the ventilation and fire safety systems for the Johor Bahru Sentral, a semi-underground train station, part of the Integrated Custom, Immigration and Quarantine Complex (ICIQ) is based on normal Malaysian Standards (MS), British Standards and the local fire department’s requirements. However, the large and complex space in the underground station coupled with scheduled diesel-powered locomotives which frequent the station by stopping or passing require detailed simulations. Both ventilation and the fire safety systems employ Computational Fluid Dynamic (CFD) methods to provide realistic balance against the typical calculations based on spread sheets and certain design software. This study compares smoke simulations results performed by the mechanical and fire consultants with the simulations carried out through this project. An assumption of a locomotive catches fire near the main platform is made. The burning locomotive is the source of the smoke while the occupants on platforms and waiting areas are the subjects to escape safely. The process of the simulation includes modelling and meshing processes on the structure of the railway station imported from Inventor CAD Autodesk software drawing. The CFD simulations are performed using Star-CCM+. The smokes flow around the building with buoyancy forces and extracted via exhaust fans. Through these simulations, we found that when a locomotive catches fire, the passengers could evacuate the building safely before the fire department machinery arrives. Furthermore, we notice that the ventilation fans activation based on detection of hazardous gases may not be efficient way to remove the latter. A schedule clean-up sync with train arrivals effectively removes toxic gas.

scholarly journals A Computational Fluid Dynamic Study of Developed Parallel Stations for Primary Fans

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1607
Author(s):  
Juan Pablo Hurtado ◽  
Gabriel Reyes ◽  
Juan Pablo Vargas ◽  
Enrique Acuña
Keyword(s):  
Computational Fluid Dynamic ◽  
Energy Cost ◽  
Fluid Dynamic ◽  
Shock Pressure ◽  
Cfd Model ◽  
Blade Angle ◽  
Cfd Simulations ◽  
Pressure Losses ◽  
Operating Points ◽  
Over Time

A Computational fluid dynamic (CFD) model was developed considering three geometries for primary parallel fan stations that have already been developed, implemented, and are currently in operation within Chilean mines. To standardize the comparison, the same primary fan was used in all the simulations with a unique set of settings (speed, blade angle, and density). The CFD representation was used to determine the operating point per configuration and compare the performances in terms of airflow and pressure delivered. This approach allowed ranking primary fan station geometry based on resistance curve and energy consumption of the fan. This paper presents the results obtained through the CFD simulations and the corresponding primary fans operating points of each configuration: symmetrical branches (SB), overlap branches (OB), and run around (RA) bypass. The RA configuration was identified as the best-performing station geometry on the lowest frictional and shock pressure losses, highest airflow delivery, and lowest energy cost. The results are discussed, considering pressure, velocity, and vector contours to understand the fluid dynamics phenomena occurring inside the station. The capital cost involved in the development of each primary parallel station was considered in the analysis in addition to the energy cost to determine the economic configuration over time.

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