Estimation of geometry factor of header pipe by CFD

The Gibson method utilizes the effect of water hammer phenomenon (hydraulic transients) in a pipeline for flow rate determination. The method consists in measuring a static pressure difference, which occurs between two cross-sections of the pipeline as a result of a temporal change of momentum from t0 to t1. This condition is induced when the water flow in the pipeline is stopped suddenly using a cut-off device. The flow rate is determined by integrating, within a proper time interval, the measured pressure difference change caused by the water hammer (inertia effect). However, several observations demonstrate that changes of pipeline geometry like diameter change, bifurcations, or direction shift by elbows may produce an effect on the computation of the flow rate. The paper focuses on this effect. Computational simulations have shown that the boundary layer separates when the flow faces sudden changes like these mentioned to above. The separation may reduce the effective cross section area of flow modifying a geometry factor involved into the computation of the flow rate. The remainder is directed to quantify the magnitude of such a factor under the influence of pipeline geometry changes. Results of numerical computations are discussed on the basis of how cross section reductions impact on the geometry factor magnitude and consequently on the mass flow rate.

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The solid angle (geometry factor) for a spherical surface source and an arbitrary detector aperture

Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment ◽

10.1016/j.nima.2015.12.060 ◽

2016 ◽

Vol 813 ◽

pp. 29-35 ◽

Cited By ~ 2

Author(s):

Jeffrey A. Favorite

Keyword(s):

Solid Angle ◽

Spherical Surface ◽

Surface Source ◽

Geometry Factor

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LOOPS, SURFACES AND GRASSMANN REPRESENTATION IN TWO- AND THREE-DIMENSIONAL ISING MODELS

International Journal of Modern Physics A ◽

10.1142/s0217751x9900213x ◽

1999 ◽

Vol 14 (29) ◽

pp. 4549-4574 ◽

Cited By ~ 3

Author(s):

C. R. GATTRINGER ◽

S. JAIMUNGAL ◽

G. W. SEMENOFF

Keyword(s):

Three Dimensional ◽

Ising Models ◽

Algebraic Representation ◽

Simple Derivation ◽

Counting Problems ◽

Intrinsic Geometry ◽

Geometry Factor ◽

Loop Expansion ◽

Loop Surface

We construct an algebraic representation of the geometrical objects (loop and surface variables) dual to the spins in 2 and 3D Ising models. This algebraic calculus is simpler than dealing with the geometrical objects, in particular when analyzing geometry factors and counting problems. For the 2D case we give the corrected loop expansion of the free energy and the radius of convergence for this series. For the 3D case we give a simple derivation of the geometry factor which prevents overcounting of surfaces in the intrinsic geometry representation of the partition function, and find a classification of the surfaces to be summed over. For 2 and 3D we derive a compact formula for 2n-point functions in loop (surface) representation.

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Critical distances in geometry factor calculations using solid state nuclear track detectors (SSNTD)

Nuclear Instruments and Methods in Physics Research ◽

10.1016/0167-5087(84)90261-8 ◽

1984 ◽

Vol 223 (1) ◽

pp. 161-165 ◽

Cited By ~ 1

Author(s):

Hameed A. Khan ◽

Naeem A. Khan

Keyword(s):

Solid State ◽

Geometry Factor ◽

Nuclear Track Detectors

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Effects of the geometry factor on the reflection loss characteristics of the modified lanthanum manganite

Journal of Physics Conference Series ◽

10.1088/1742-6596/1091/1/012028 ◽

2018 ◽

Vol 1091 ◽

pp. 012028 ◽

Cited By ~ 2

Author(s):

Wisnu Ari Adi ◽

Yosef Sarwanto ◽

Yana Taryana ◽

Bambang Soegijono

Keyword(s):

Reflection Loss ◽

Lanthanum Manganite ◽

Geometry Factor

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Parametric Study on the Flow Profiles of Vertical Sinter Cooling Bed Using the DEM and Taguchi Method for Waste Heat Recovery

Energies ◽

10.3390/en13195030 ◽

2020 ◽

Vol 13 (19) ◽

pp. 5030

Author(s):

Junpeng Fu ◽

Jiuju Cai

Keyword(s):

Aspect Ratio ◽

Taguchi Method ◽

Waste Heat ◽

Flow Characteristics ◽

Flow Distribution ◽

External Factors ◽

Influential Factor ◽

Geometry Factor ◽

Discharge Velocity ◽

Performance Of Heat Transfer

To comprehensively understand the effectiveness of external factors on flow characteristics and realize particle flow distribution evenly in bulk layers is an essential prerequisite for improving the performance of heat transfer in vertical sinter cooling beds (VSCBs). The numerical discrete element method (DEM) was applied to investigate external geometric and operational factors, such as the aspect ratio, geometry factor, half hopper angle, normalized outlet scale, and discharge velocity. Using the Taguchi method, a statistical analysis of the effect of design factors on response was performed. In this study, we focused more on external factors than granular properties, be remodelling the external factors was more useful and reliable for actual production in industries. The results showed that the most important factor was the aspect ratio, followed by the geometry factor, normalized outlet scale, half hopper angle, and discharge velocity for the dimensionless height of mass flow. In terms of the Froude number, the most influential factor was the normalized outlet scale with a contribution ratio of 33.81%, followed by the aspect ratio (22.86%), geometry factor (17.73%), discharge velocity (17.73%), and half hopper angle (11.83%).

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A Reconsideration of the Geometry Factor for the Standard and Profile Shifted Teeth

Journal of Mechanisms Transmissions and Automation in Design ◽

10.1115/1.3259013 ◽

1989 ◽

Vol 111 (3) ◽

pp. 402-413 ◽

Cited By ~ 3

Author(s):

J. H. Kuang ◽

Y. T. Yang

Keyword(s):

Stress Concentration ◽

Stress Distribution ◽

Stress Concentration Factor ◽

Empirical Equation ◽

Design Parameters ◽

Spur Gears ◽

Geometry Factor ◽

Gear Teeth ◽

Semi Empirical

A semi-empirical equation for the determination of the stress concentration factor for spur gears is introduced. The effects of some design parameters such as fillet radii of rack cutters, teeth number, and profile shifting factor, on the stress distribution at the fillets of gear teeth are investigated. Values of the modified geometry factors for the standard and profile shifted teeth are also derived. It is hoped that the present investigation may yield a more accurate prediction of the localized stresses at tooth fillets than the results thus far available.

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The Determination of the Lewis Form Factor and the AGMA Geometry Factor J for External Spur Gear Teeth

Journal of Mechanical Design ◽

10.1115/1.3256305 ◽

1982 ◽

Vol 104 (1) ◽

pp. 148-158 ◽

Cited By ~ 16

Author(s):

R. G. Mitchiner ◽

H. H. Mabie

Keyword(s):

Form Factor ◽

Spur Gear ◽

Constant Stress ◽

Direct Approach ◽

Center Line ◽

Geometry Factor ◽

Gear Teeth ◽

Definition Of ◽

Line Intercept

This paper presents a simple and direct approach to the problem of the definition of the root profile for standard and nonstandard external spur gear teeth. Equations are developed for the location of the tooth center-line intercept at the constant-stress parabola. Also, the expression for the location of the point of tangency of the parabola with the root trochoid is given as well as the derivative of this expression. The AGMA Standards present charts of geometry factors, but the method by which these factors were determined is graphical and in some instances is not sufficiently accurate nor convenient to use. Although other investigators have considered this problem, their methods are either graphical or very complicated analytically. This treatment of the problem has been developed because it is not available in the open literature. Tables and charts are given for both Y and J factors for many profile variations.

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