scholarly journals Air barriers used for separating smoke free zones in case of fire in tunnel

2014 ◽  
Vol 13 (4) ◽  
pp. 015-022
Author(s):  
Grzegorz Krajewski
Keyword(s):  
Pressure Drop ◽  
Turbulence Model ◽  
Scale Model ◽  
Air Velocity ◽  
Air Curtain ◽  
Flow Through ◽  
Real Scale ◽  
Thin Nozzle ◽  
Transversal Flow

The aim of this paper is to take the advantage of CFD application in calculating, optimising, and designing air curtains used to separate smoke free zones in case of fire in tunnel. Air curtains can be a good solution in case when the usage of solid obstructions is not feasible(for example in a big tunnel). A properly designed air curtain produces a pressure drop which prevents transversal flow through the opening. An accurate CFD calculation of an air curtain is challenging because of the high air velocity and relatively thin nozzle. Most air curtains are tested on scaled down models which are difficult to extrapolate. Tests in a real scale model are performed and the tests results are used to verify the chosen turbulence model. The intention of this paper is to present the comparison between the CFD calculations and tests results.

scholarly journals Verification of computational calculations based on physical tests of plane jet used to separate zones full of smoke

2013 ◽  
Vol 12 (2) ◽  
pp. 135-141
Author(s):  
Grzegorz Krajewski
Keyword(s):  
Pressure Drop ◽  
Scale Model ◽  
Air Curtain ◽  
Computational Calculations ◽  
Physical Tests ◽  
Flow Through ◽  
Plane Jet ◽  
Real Scale ◽  
Thin Nozzle ◽  
Transversal Flow

The aim of this paper is to take advantage of CFD application in calculating, optimizing, and designing air barriers used to separate smoke free zones in the case of fire. Properly designed air curtain produces a pressure drop which forbides transversal flow through the opening. It is hard to make a good quality CFD calculation of that kind of air curtain because of high velocity and relatively thin nozzle. Most air curtains are tested on scaled down models which are difficult to extrapolate. The author of this article performed tests in a real scale model. Tests results were used to verify chosen turbulence model. The intention of this paper is to present the comparison between CFD calculations and tests results.

Numerical and Experimental Study of Pressure Drop Reduction in a Power Plant Stack

2004 ◽  
Author(s):  
Murthy Lakshmiraju ◽  
Jie Cui ◽  
Stephen Idem ◽  
Sastry Munukutla
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Power Plants ◽  
Experimental Studies ◽  
Maximum Flow ◽  
Scale Model ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through

As governmental regulations on the emission of the power industry became more restrictive, many power plants operating today experience severe problems. The fans that handle the flow through the stack, that were originally designed to handle a certain maximum flow rate, are now required to handle even higher flow rates due to the introduction of emission control devices. In this study, computational fluid dynamics (CFD) and experimental studies have been carried out on the scale model of a stack to identify means for pressure drop reduction. The CFD model was constructed using the commercial software CFX-5.6. The model solves the Reynolds averaged Navier-Stokes equation with Shear-Stress turbulence model (SST) and the CFD results are validated by data taken from the scale model. Baffles of different orientation have been installed in the stack under different flow conditions. Both numerical and experimental results confirm that adding baffles can reduce the pressure drop in a stack significantly. Thus, with minimum effort, power plants can keep running the stacks at a higher flow rate.

scholarly journals Experimental Study on the Ventilation Resistance Characteristics of Paddy Grain Layer Modelled with Response Surface Methodology

2021 ◽  
Vol 11 (17) ◽  
pp. 7826
Author(s):  
Xiaoming Wang ◽  
Chongyang Han ◽  
Weibin Wu ◽  
Jian Xu ◽  
Zhiheng Zeng ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Pressure Drop ◽  
Moisture Content ◽  
Response Surface ◽  
Second Order ◽  
Rice Grain ◽  
Air Velocity ◽  
Layer Depth ◽  
Grain Moisture ◽  
Flow Through

The ventilation resistance of air flow through rice grain layers is one of the key parameters affecting drying uniformity as well as the energy consumption of the drying process. In order to reveal the variation of characteristics of the ventilation resistance with paddy grain moisture content, the air velocity and the bed layer depth are needed. A second order model was fitted to pressure drop using the response surface methodology and the results are compared with those of the Ergun model. The results showed that the pressure drop increases with the increase of paddy grain moisture content, air velocity and the bed layer depth, and the interactions between the air velocity and the bed layer depth have the most significant influence on the pressure drop. Moreover, a second-order polynomial pressure drop model based on RSM was established and compared with the Ergun model. The results showed that the pressure drop model established by RSM is similar to that of the Ergun model.

ESTIMATION OF PRESSURE DROP FOR NON-NEWTONIAN LIQUID FLOW THROUGH BENDS USING ADAPTIVE NON-PARAMETRIC MODEL

2020 ◽  
Vol 47 (1) ◽  
pp. 59-69
Author(s):  
Suman Debnath ◽  
Anirban Banik ◽  
Tarun Kanti Bandyopadhyay ◽  
Mrinmoy Majumder ◽  
Apu Kumar Saha
Keyword(s):  
Pressure Drop ◽  
Liquid Flow ◽  
Parametric Model ◽  
Newtonian Liquid ◽  
Flow Through ◽  
Non Parametric

HEAT TRANSFER AND PRESSURE DROP IN TURBULENT FLOW THROUGH A TUBE WITH LONGITUDINAL PERFORATED STAR-SHAPED INSERTS

2011 ◽  
Vol 18 (6) ◽  
pp. 491-502 ◽  
Author(s):  
Andrew Mintu Sarkar ◽  
M. A. Rashid Sarkar ◽  
Mohammad Abdul Majid
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Turbulent Flow ◽  
Flow Through

Pressure Drop for Oil-Gas Two-Phase Flow Through Straight Horizontal Pipe

2007 ◽  
Author(s):  
Wenhong Liu ◽  
Liejin Guo ◽  
Ximin Zhang ◽  
Kai Lin ◽  
Long Yang ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Flow Through ◽  
Oil Gas

Study of fluid flow through a channel deformed by piezoelement

2018 ◽  
Vol 13 (3) ◽  
pp. 1-10 ◽  
Author(s):  
I.Sh. Nasibullayev ◽  
E.Sh Nasibullaeva ◽  
O.V. Darintsev
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Boundary Conditions ◽  
Flow Rate ◽  
Contact Surface ◽  
Piezoelectric Element ◽  
Neumann Boundary ◽  
Differential Pressure ◽  
Physical Parameters ◽  
Flow Through

The flow of a liquid through a tube deformed by a piezoelectric cell under a harmonic law is studied in this paper. Linear deformations are compared for the Dirichlet and Neumann boundary conditions on the contact surface of the tube and piezoelectric element. The flow of fluid through a deformed channel for two flow regimes is investigated: in a tube with one closed end due to deformation of the tube; for a tube with two open ends due to deformation of the tube and the differential pressure applied to the channel. The flow rate of the liquid is calculated as a function of the frequency of the deformations, the pressure drop and the physical parameters of the liquid.

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