The Fluid Dynamics of Safety Valve Vent Stacks

1985 ◽  
Vol 107 (3) ◽  
pp. 397-401
Author(s):  
M. Samimy ◽  
A. L. Addy
Keyword(s):  
Fluid Dynamics ◽  
Theoretical Analysis ◽  
Computer Program ◽  
Flow Model ◽  
Safety Valve ◽  
Flow Theory ◽  
Base Flow ◽  
Experimental Results ◽  
Flow Through

The flow through a safety valve vent stack system has been modeled and analyzed theoretically and experimentally. The theoretical analysis is based on the well known Chapman-Korst base flow theory. The base flow model is augmented with an empirically determined recompression factor to improve agreement between the theoretical analysis and experimental results. A computer program has been developed to solve the equations and provide necessary information to designers.

Steam Flow Through Safety Valve Vent Pipes

1976 ◽  
Vol 98 (2) ◽  
pp. 199-206
Author(s):  
H. E. Brandmaier ◽  
M. E. Knebel
Keyword(s):  
Fluid Dynamics ◽  
Safety Valve ◽  
Design Procedure ◽  
Steam Flow ◽  
Wind Tunnels ◽  
Pipe System ◽  
Free Jet ◽  
Design Basis ◽  
Flow Through

The flow of steam through a safety valve vent pipe system has been analyzed to provide a design basis for sizing the pipe to prevent blowback of steam. The analysis is based upon the application of modern fluid dynamics to the flow in ejectors and free-jet wind tunnels. The resulting vent pipe design procedure is, in the authors’ opinion, based upon a more realistic analysis than has previously been performed.

Oblique weir equation using incomplete self-similarity

2006 ◽  
Vol 33 (10) ◽  
pp. 1241-1250 ◽  
Author(s):  
S M Borghei ◽  
A R Kabiri-Samani ◽  
N Nekoee
Keyword(s):  
Experimental Data ◽  
Data Analysis ◽  
Theoretical Analysis ◽  
Computer Program ◽  
Key Words ◽  
Dimensional Analysis ◽  
Flow Characteristics ◽  
Experimental Results ◽  
Trial And Error ◽  
Self Similarity

Incomplete self-similarity (ISS) concept is employed to develop the equations from existing experimental results of flow over an oblique rectangular sharp-crested weir for both free and submerged flow. The stage-discharge relationship is obtained by theoretical analysis, based on the application of the dimensional analysis and the ISS theory. For analysis, the relations were found by trial and error procedure using the SPSS mathematical computer program that estimates the relation among multi-variable functions. Thus, equations to estimate the flow characteristics for both free and submerged flow are proposed. The results show a better compatibility with the experimental data than the previous equations given by the main author. Hence, the capabilities of ISS method for similar analysis and the powerful program of SPSS for multi-variable data analysis is shown. Finally, design guides together with examples are presented to show the simple use of the graphs obtained . Key words: dimensional analysis, incomplete self-similarity (ISS), oblique weir, experimental data.

A Non-Newtonian Fluid Flow Model for the Slip Condition on Blood Flow through a Stenosed Artery using Power-law Fluid

2018 ◽  
Vol 9 (7) ◽  
pp. 871-879
Author(s):  
Rajesh Shrivastava ◽  
R. S. Chandel ◽  
Ajay Kumar ◽  
Keerty Shrivastava and Sanjeet Kumar
Keyword(s):  
Blood Flow ◽  
Fluid Flow ◽  
Newtonian Fluid ◽  
Power Law ◽  
Flow Model ◽  
Slip Condition ◽  
Power Law Fluid ◽  
Stenosed Artery ◽  
Flow Through

Frequency-Response Approach to Modelling Continuous Reactors

1971 ◽  
Vol 6 (1) ◽  
pp. 249-272
Author(s):  
P.B. Melynk ◽  
J.D. Norman ◽  
A.W. Wilson
Keyword(s):  
Frequency Response ◽  
Flow Model ◽  
Plug Flow ◽  
Order Reaction ◽  
Parameter Estimates ◽  
Second Order Reaction ◽  
Mixing Conditions ◽  
Bode Plot ◽  
Flow Through ◽  
Search Routine

Abstract It is postulated that the mixing conditions in a flow-through reactor can be characterized as having either completely mixed, completely plug flow, or some network of completely mixed and plug flow component vessels. A frequency-response technique is used to obtain an experimental Bodé plot for arbitrarily mixed vessels. The interpretation of the Bodé plot is discussed, and , in light of this interpretation, a network of plug flow and completely mixed components is specified as a flow model. A Rosenbrock search routine is used to improve the parameter estimates of the model. To verify the model, a second order reaction was run through the vessel and the experimentally measured conversion was compared to that predicted by the model. It is shown that the modeling technique, in addition to describing the mixing in the system, will indicate inactive volume, as well as measure the extent of any channeling or short circuiting in the reactor.

PHOTOINDUCED NONLINEAR OCTUPOLAR POLARIZATION: TRANSIENT AND PERMANENT REGIMES

1996 ◽  
Vol 05 (04) ◽  
pp. 653-670 ◽  
Author(s):  
CÉLINE FIORINI ◽  
JEAN-MICHEL NUNZI ◽  
FABRICE CHARRA ◽  
IFOR D.W. SAMUEL ◽  
JOSEPH ZYSS
Keyword(s):  
Theoretical Analysis ◽  
Second Harmonic ◽  
Experimental Results ◽  
Polar Field ◽  
Rotational Spectrum ◽  
Dual Frequency ◽  
One Dimensional ◽  
Ethyl Violet ◽  
Disperse Red 1 ◽  
Good Agreement

An original poling method using purely optical means and based on a dual-frequency interference process is presented. We show that the coherent superposition of two beams at fundamental and second-harmonic frequencies results in a polar field with an irreducible rotational spectrum containing both a vector and an octupolar component. This enables the method to be applied even to molecules without a permanent dipole such as octupolar molecules. After a theoretical analysis of the process, we describe different experiments aiming at light-induced noncentrosymmetry performed respectively on one-dimensional Disperse Red 1 and octupolar Ethyl Violet molecules. Macroscopic octupolar patterning of the induced order is demonstrated in both transient and permanent regimes. Experimental results show good agreement with theory.

scholarly journals A Simple Transient Poiseuille-Based Approach to Mimic the Womersley Function and to Model Pulsatile Blood Flow

Dynamics ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 9-17
Author(s):  
Andrea Natale Impiombato ◽  
Giorgio La Civita ◽  
Francesco Orlandi ◽  
Flavia Schwarz Franceschini Zinani ◽  
Luiz Alberto Oliveira Rocha ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Blood Flow ◽  
Boundary Conditions ◽  
Quadratic Function ◽  
Pulsatile Blood Flow ◽  
Flow Through ◽  
Simplified Analysis ◽  
Function Models ◽  
Flow Reversals

As it is known, the Womersley function models velocity as a function of radius and time. It has been widely used to simulate the pulsatile blood flow through circular ducts. In this context, the present study is focused on the introduction of a simple function as an approximation of the Womersley function in order to evaluate its accuracy. This approximation consists of a simple quadratic function, suitable to be implemented in most commercial and non-commercial computational fluid dynamics codes, without the aid of external mathematical libraries. The Womersley function and the new function have been implemented here as boundary conditions in OpenFOAM ESI software (v.1906). The discrepancy between the obtained results proved to be within 0.7%, which fully validates the calculation approach implemented here. This approach is valid when a simplified analysis of the system is pointed out, in which flow reversals are not contemplated.

The Effect of Different Turbulence Models on the Emitter Discharge by Using Computational Fluid Dynamics

2013 ◽  
Vol 662 ◽  
pp. 586-590
Author(s):  
Gang Lu ◽  
Qing Song Yan ◽  
Bai Ping Lu ◽  
Shuai Xu ◽  
Kang Li
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Turbulence Models ◽  
Experimental Results ◽  
Turbulent Model ◽  
Simulation Results ◽  
Rsm Model ◽  
Dynamics Method ◽  
Emitter Discharge

Four types of Super Typhoon drip emitter with trapezoidal channel were selected out for the investigation of the flow field of the channel, and the CFD (Computational Fluid Dynamics) method was applied to simulate the micro-field inside the channel. The simulation results showed that the emitter discharge of different turbulent model is 4%-14% bigger than that of the experimental results, the average discharge deviation of κ-ω and RSM model is 5, 4.5 respectively, but the solving efficiency of the κ-ω model is obviously higher than that of the RSM model.

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