Drag coefficient of small spherical particles.

AIAA Journal ◽  
1968 ◽  
Vol 6 (3) ◽  
pp. 401-408 ◽  
Author(s):  
B. P. SELBERG ◽  
J. A. NICHOLLS
Keyword(s):  
Drag Coefficient ◽  
Spherical Particles

Settling Behavior of Particles in Bubble Containing Newtonian Fluids: Experimental Study and Model Development

2021 ◽  
Author(s):  
Silin Jing ◽  
Xianzhi Song ◽  
Zhaopeng Zhu ◽  
Buwen Yu ◽  
Shiming Duan
Keyword(s):  
Reynolds Number ◽  
Drag Coefficient ◽  
Volume Concentration ◽  
Settling Velocity ◽  
Particle Density ◽  
Particle Diameter ◽  
Newtonian Fluids ◽  
Spherical Particles ◽  
Bubble Volume ◽  
Particle Reynolds Number

Abstract Accurate description of cuttings slippage in the gas-liquid phase is of great significance for wellbore cleaning and the control accuracy of bottom hole pressure during MPD. In this study, the wellbore bubble flow environment was simulated by a constant pressure air pump and the transparent wellbore, and the settling characteristics of spherical particles under different gas volume concentrations were recorded and analyzed by highspeed photography. A total of 225 tests were conducted to analyze the influence of particle diameter (1–12mm), particle density (2700–7860kg/m^3), liquid viscosity and bubble volume concentration on particle settling velocity. Gas drag force is defined to quantitatively evaluate the bubble’s resistance to particle slippage. The relationship between bubble drag coefficient and particle Reynolds number is obtained by fitting the experimental results. An explicit settling velocity equation is established by introducing Archimedes number. This explicit equation with an average relative error of only 8.09% can directly predict the terminal settling velocity of the sphere in bubble containing Newtonian fluids. The models for predicting bubble drag coefficient and the terminal settling velocity are valid with particle Reynolds number ranging from 0.05 to 167 and bubble volume concentration ranging from 3.0% to 20.0%. Besides, a trial-and-error procedure and an illustrative example are presented to show how to calculate bubble drag coefficient and settling velocity in bubble containing fluids. The results of this study will provide the theoretical basis for wellbore cleaning and accurate downhole pressure to further improve the performance of MPD in treating gas influx.

Comment on "Drag Coefficient of Small Spherical Particles"

AIAA Journal ◽  
1969 ◽  
Vol 7 (3) ◽  
pp. 573-574
Author(s):  
FREDERICK L. SCHUYLER
Keyword(s):  
Drag Coefficient ◽  
Spherical Particles

scholarly journals The effect of Stefan flow on the drag coefficient of spherical particles in a gas flow

2019 ◽  
Vol 117 ◽  
pp. 130-137 ◽  
Author(s):  
Thamali R. Jayawickrama ◽  
Nils Erland L. Haugen ◽  
Matthaus U. Babler ◽  
M.A. Chishty ◽  
Kentaro Umeki
Keyword(s):  
Drag Coefficient ◽  
Gas Flow ◽  
Spherical Particles ◽  
Stefan Flow

Shape Description and Sedimentation Characteristics of Non Spherical Regular Particles

2013 ◽  
Vol 316-317 ◽  
pp. 1083-1086
Author(s):  
Song Lin Yi ◽  
Zhi Ming Wang ◽  
Xian Zhong Yi ◽  
Wen Ni Wan ◽  
Hai Ying Qi
Keyword(s):  
Mathematical Model ◽  
Drag Coefficient ◽  
Arbitrary Shape ◽  
Spherical Particles ◽  
Research Progress ◽  
Shape Description ◽  
Reasonable Accuracy ◽  
Shape Information ◽  
Settling Characteristics

The research progress on settling characteristics of non-spherical particles is summarized. Three new filling coefficients in three directions of cuboid are defined. Combining with the existing parameters, a new mathematical model of drag coefficient CD is proposed that using six variables describes the shape information of arbitrary shape particles. This equation is derived and shows reasonable accuracy with the error being less than 1%.

Explicit relationships for the terminal velocity of spherical particles

1990 ◽  
Vol 55 (2) ◽  
pp. 403-408 ◽  
Author(s):  
Miloslav Hartman ◽  
Václav Veselý ◽  
Karel Svoboda ◽  
Vladimír Havlín
Keyword(s):  
Drag Coefficient ◽  
Free Fall ◽  
Terminal Velocity ◽  
Spherical Particles ◽  
Wide Range ◽  
Archimedes Number

The Turton-Levenspiel correlation for the drag coefficient of a sphere is employed to compare recently proposed explicit equations to predict the free-fall conditions. Predictions of four different expressions are explored over a wide range of Archimedes number.

Sign in / Sign up

Export Citation Format

Share Document