scholarly journals Computational study of smoke flow control in garage fires and optimization of the ventilation system

2009 ◽  
Vol 13 (1) ◽  
pp. 69-78
Author(s):  
Milos Banjac ◽  
Barbara Nikolic
Keyword(s):  
Computational Study ◽  
Ventilation System ◽  
Operating Mode ◽  
Dynamics Simulation ◽  
Computational Fluid Dynamics Simulation ◽  
Start Time ◽  
Combustion Dynamics ◽  
Operating Modes ◽  
Smoke Flow ◽  
Emergency Operating

With the aim of evaluating capabilities of a ventilation system to control the spread of smoke in the emergency operating mode, thereby providing conditions for safe evacuation of people from a fire-struck area, computational fluid dynamics simulation of a fire in a semi-bedded garage was conducted. Using the experimental results of combustion dynamics of a passenger car on fire, optimal positions of ventilation openings were determined. According to recommendations by DIN EN 12101 standard, the operating modes of a ventilation system were verified and optimal start time of the smoke extraction system was defined.

Dynamics and Stability Limits of Syngas Combustion in a Backward-Facing Step Combustor

2007 ◽  
Author(s):  
Raymond L. Speth ◽  
H. Murat Altay ◽  
Ahmed F. Ghoniem
Keyword(s):  
High Speed ◽  
Vortex Method ◽  
Operating Mode ◽  
Operating Conditions ◽  
Video Data ◽  
Stable Region ◽  
Small Scale ◽  
Flammability Limit ◽  
Combustion Dynamics ◽  
Operating Modes

The stability bands and combustion dynamics of syngas under different operating conditions and fuel compositions are investigated. Pressure measurements and high-speed video data are used to distinguish three operating modes. A stable region near the lean flammability limit is characterized by the shedding of small-scale vortices in the shear-layer. A quasistable region is present at intermediate equivalence ratios. At high equivalence ratios, we observe an unstable operating mode characterized by the periodic interaction between a large vortex and the flame. As the amount of hydrogen in the fuel is increased, the lean flammability limit is extended and transitions between operating regimes moves to lower equivalence ratios. Numerical simulations performed using a vortex method correspond to the experimental measurements and confirm the observed instability mechanism.

scholarly journals Investigation of Check Valve Aerodynamic Characteristics in Different Operating Modes

2018 ◽  
Vol 3 (3) ◽  
pp. 127
Author(s):  
D.A. Pakholik ◽  
A.V. Sobolev ◽  
A.S. Shelegov
Keyword(s):  
Numerical Simulation ◽  
Computational Study ◽  
Ventilation System ◽  
Check Valve ◽  
Aerodynamic Characteristics ◽  
Air Velocity ◽  
Valve Body ◽  
Operating Modes ◽  
System Check ◽  
Actual Flow Rate

The paper presents a computational study of the NPP ventilation system check valve aerodynamics, namely, a numerical simulation of the air flowing through the open valve with the subsequent determination of the relationship between the reactive torque acting on the valve closure axles and the input air velocity.This numerical simulation of the air flowing through the check valve was performed using the ANSYS CFX program. In the computation, different operating modes of the check valve were considered when the air flow was passing through it. The valve operating modes were set depending on changes in the input air velocity. As a result of aerodynamic computation, the values of pressure and velocity components were obtained over the entire valve volume.Reactive forces were calculated in the ANSYS Mechanical program. The reactive forces acting on the valve body form a torque at the gate axles. When adjusting the check valve to the actual flow rate, it is necessary to know this torque value and compensate for it. As a result of a series of computations of reactive forces, a relationship was found between the torque value of the valve’s working element axles and the input air velocity. 

scholarly journals Computational Study on Selective PDE9 Inhibitors on PDE9-Mg/Mg, PDE9-Zn/Mg, and PDE9-Zn/Zn Systems

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 709
Author(s):  
Dakshinamurthy Sivakumar ◽  
Sathish-Kumar Mudedla ◽  
Seonghun Jang ◽  
Hyunjun Kim ◽  
Hyunjin Park ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Erectile Dysfunction ◽  
Molecular Docking ◽  
Molecular Dynamics Simulation ◽  
Cardiovascular Diseases ◽  
Neurodegenerative Disorders ◽  
Computational Study ◽  
Dynamics Simulation ◽  
Interaction Patterns

PDE9 inhibitors have been studied to validate their potential to treat diabetes, neurodegenerative disorders, cardiovascular diseases, and erectile dysfunction. In this report, we have selected highly potent previously reported selective PDE9 inhibitors BAY73-6691R, BAY73-6691S, 28r, 28s, 3r, 3s, PF-0447943, PF-4181366, and 4r to elucidate the differences in their interaction patterns in the presence of different metal systems such as Zn/Mg, Mg/Mg, and Zn/Zn. The initial complexes were generated by molecular docking followed by molecular dynamics simulation for 100 ns in triplicate for each system to understand the interactions’ stability. The results were carefully analyzed, focusing on the ligands’ non-bonded interactions with PDE9 in different metal systems.

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