scholarly journals THE EFFICIENCY OF THE GAVER-STEHFEST METHOD TO SOLVE OF ONE-DIMENSIONAL GAS FLOW MODEL

2017 ◽  
Vol 11 (1) ◽  
pp. 246-252
Author(s):  
Małgorzata Wójcik ◽  
Mirosław Szukiewicz ◽  
Paweł Kowalik ◽  
Wiesław Próchniak
Keyword(s):  
Gas Flow ◽  
Flow Model ◽  
One Dimensional

Measurements of Blowdown Thrust Loading in Natural Gas Facilities

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
K. K. Botros ◽  
H. Charette ◽  
M. Martens ◽  
M. Beckel ◽  
G. Szuch
Keyword(s):  
Experimental Data ◽  
Natural Gas ◽  
Compressible Flow ◽  
Gas Flow ◽  
Flow Model ◽  
Stagnation Pressure ◽  
Flow Meters ◽  
One Dimensional ◽  
Pressure Losses ◽  
Modeling Approach

Abstract The thrust loading on a vertical blowdown stack during a natural gas blowdown was investigated using a combined experimental and modeling approach. A gravimetric vessel initially at 4000 kPa-g was blown down through two geometrically different stack assemblies. Thrust loads were measured using a dynamic weigh scale typically used for gravimetric calibration of gas flow meters. A one-dimensional (1D) compressible flow model, calibrated using the experimental data, revealed stagnation pressure losses at the entrance to the riser, resulting in lower thrust loads. A comparison between thrust loading obtained from the measurements and the 1D compressible flow model is presented. This work shows that the analytical flow model predicts the blowdown thrust loads within ±30%.

Experimental and Analytical Study of Flow Diversion Beyond an Underexpanded Nozzle

1991 ◽  
Vol 113 (3) ◽  
pp. 475-478
Author(s):  
E. C. Hansen
Keyword(s):  
Gas Flow ◽  
Analytical Study ◽  
Flow Model ◽  
Ambient Pressure ◽  
Experimental Studies ◽  
Analytic Model ◽  
Steady State Flow ◽  
One Dimensional ◽  
Nozzle Pressure ◽  
Flow Apparatus

A steady-state flow apparatus was used to investigate the process of gun gas diversion through a single hole perforated disk diverter. The amount of diverted flow was found to depend on the distance between the nozzle and the diverter disk and the ratio of nozzle pressure to diverter exit pressure. Experimental studies used nitrogen and carbon dioxide as the working fluids to show the effect of specific heat ratio. At ratios of nozzle pressure to ambient pressure ranging from 4 to 60 diversion efficiencies of 50 to 99 percent were produced. A one-dimensional analytic gas flow model was developed. Results of the analytic model paralleled the experimental data for pressure ratios over 10.

A ONE-DIMENSIONAL TWO-PHASE FLOW MODEL AND EXPERIMENTAL VALIDATION FOR A FLASHING VISCOUS LIQUID IN A SPLASH PLATE NOZZLE

2015 ◽  
Vol 25 (9) ◽  
pp. 795-817 ◽  
Author(s):  
Mika P. Jarvinen ◽  
A. E. P. Kankkunen ◽  
R. Virtanen ◽  
P. H. Miikkulainen ◽  
V. P. Heikkila
Keyword(s):  
Viscous Liquid ◽  
Experimental Validation ◽  
Flow Model ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
One Dimensional

On the theory of electrohydrodynamically driven capillary jets

1997 ◽  
Vol 335 ◽  
pp. 165-188 ◽  
Author(s):  
ALFONSO M. GAÑÁN-CALVO
Keyword(s):  
Surface Charge ◽  
Electric Fields ◽  
Gas Flow ◽  
Wave Speed ◽  
Propagation Speed ◽  
Field Equations ◽  
Steady Regime ◽  
One Dimensional ◽  
Relaxation Effects ◽  
Capillary Jets

Electrohydrodynamically (EHD) driven capillary jets are analysed in this work in the parametrical limit of negligible charge relaxation effects, i.e. when the electric relaxation time of the liquid is small compared to the hydrodynamic times. This regime can be found in the electrospraying of liquids when Taylor's charged capillary jets are formed in a steady regime. A quasi-one-dimensional EHD model comprising temporal balance equations of mass, momentum, charge, the capillary balance across the surface, and the inner and outer electric fields equations is presented. The steady forms of the temporal equations take into account surface charge convection as well as Ohmic bulk conduction, inner and outer electric field equations, momentum and pressure balances. Other existing models are also compared. The propagation speed of surface disturbances is obtained using classical techniques. It is shown here that, in contrast with previous models, surface charge convection provokes a difference between the upstream and the downstream wave speed values, the upstream wave speed, to some extent, being delayed. Subcritical, supercritical and convectively unstable regions are then identified. The supercritical nature of the microjets emitted from Taylor's cones is highlighted, and the point where the jet switches from a stable to a convectively unstable regime (i.e. where the propagation speed of perturbations become zero) is identified. The electric current carried by those jets is an eigenvalue of the problem, almost independent of the boundary conditions downstream, in an analogous way to the gas flow in convergent–divergent nozzles exiting into very low pressure. The EHD model is applied to an experiment and the relevant physical quantities of the phenomenon are obtained. The EHD hypotheses of the model are then checked and confirmed within the limits of the one-dimensional assumptions.

Diabatic Nozzle Flow with Constant Small Stage Efficiency

1960 ◽  
Vol 64 (598) ◽  
pp. 632-635 ◽  
Author(s):  
R. A. A. Bryant
Keyword(s):  
Gas Flow ◽  
Nozzle Flow ◽  
Flow Conditions ◽  
One Dimensional ◽  
Real Flow ◽  
Stage Efficiency ◽  
Frictional Effects

The concept of small stage efficiency is introduced when studying one-dimensional gas flow in nozzles in order to permit a closer approximation of real flow conditions than is possible from an isentropic analysis. It is more or less conventional to assume the flow conditions are adiabatic whenever the small stage efficiency is used. That is to say, small stage efficiency is generally considered in relation to flows contained within adiabatic boundaries, in which case it becomes a measure of the heat generated by internal frictional effects alone.

An Evaluation of the Average Flow Model [1] for Surface Roughness Effects in Lubrication

1980 ◽  
Vol 102 (3) ◽  
pp. 360-366 ◽  
Author(s):  
J. L. Teale ◽  
A. O. Lebeck
Keyword(s):  
Surface Roughness ◽  
Flow Model ◽  
Two Dimensional ◽  
Roughness Effects ◽  
Important Conclusion ◽  
Average Flow ◽  
One Dimensional ◽  
Dimensional Flow ◽  
Two Dimensional Flow ◽  
Average Flow Model

The average flow model presented by Patir and Cheng [1] is evaluated. First, it is shown that the choice of grid used in the average flow model influences the results. The results presented are different from those given by Patir and Cheng. Second, it is shown that the introduction of two-dimensional flow greatly reduces the effect of roughness on flow. Results based on one-dimensional flow cannot be relied upon for two-dimensional problems. Finally, some average flow factors are given for truncated rough surfaces. These can be applied to partially worn surfaces. The most important conclusion reached is that an even closer examination of the average flow concept is needed before the results can be applied with confidence to lubrication problems.

Sign in / Sign up

Export Citation Format

Share Document