Experimental Investigations of Single Bubble Rising in Static Newtonian Fluids as a Function of Temperature Using a Modified Drag Coefficient

2019 ◽  
Vol 29 (3) ◽  
pp. 2209-2226 ◽  
Author(s):  
Nannan Liu ◽  
Yong Yang ◽  
Jian Wang ◽  
Binshan Ju ◽  
Eric Thompson Brantson ◽  
...  
Keyword(s):  
Drag Coefficient ◽  
Newtonian Fluids ◽  
Single Bubble ◽  
Experimental Investigations ◽  
Bubble Rising

The Drag Coefficient and the Shape for a Single Bubble Rising in Non-Newtonian Fluids

2012 ◽  
Vol 134 (8) ◽  
Author(s):  
Shaobai Li ◽  
Youguang Ma ◽  
Shaokun Jiang ◽  
Taotao Fu ◽  
Chunying Zhu ◽  
...  
Keyword(s):  
Drag Coefficient ◽  
High Speed ◽  
Newtonian Fluids ◽  
Single Bubble ◽  
Dynamical Characteristic ◽  
Wide Range ◽  
Coefficient Corrélation ◽  
Deformed Bubble ◽  
Bubble Rising ◽  
Experimental Values

The dynamical characteristic of a single bubble rising in non-Newtonian fluid was investigated experimentally. The bubble aspect ratio and rising velocity were measured by high speed camera. The shape regimes for bubbles in non-Newtonian fluids was plotted by means of Reynolds number Re, Eötvös number Eo and Morton number Mo. The effects of bubble shape and liquid rheological property on the total bubble drag coefficient were studied. A new empirical drag coefficient correlation covering spherical bubble and deformed bubble was proposed, the predicted results shows good conformity to experimental values over a wide range of 0.05 < Re < 300.

Drag Coefficient Prediction of a Single Bubble Rising in Liquids

2018 ◽  
Vol 57 (15) ◽  
pp. 5385-5393 ◽  
Author(s):  
Xiaokang Yan ◽  
Kaixin Zheng ◽  
Yan Jia ◽  
Zhenyong Miao ◽  
Lijun Wang ◽  
...  
Keyword(s):  
Drag Coefficient ◽  
Single Bubble ◽  
Bubble Rising

Drag coefficient fluctuation prediction of a single bubble rising in water

2017 ◽  
Vol 316 ◽  
pp. 553-562 ◽  
Author(s):  
Xiaokang Yan ◽  
Yan Jia ◽  
Lijun Wang ◽  
Yijun Cao
Keyword(s):  
Drag Coefficient ◽  
Single Bubble ◽  
Bubble Rising

Experimental investigations of flow over NACA airfoils 0021 and 4412 of wind turbine blades with and without Tubercles

2021 ◽  
pp. 0309524X2110071
Author(s):  
Usman Butt ◽  
Shafqat Hussain ◽  
Stephan Schacht ◽  
Uwe Ritschel
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
Wind Turbine ◽  
Critical Region ◽  
Lift Coefficient ◽  
Turbine Blades ◽  
Leading Edge ◽  
Reynolds Numbers ◽  
Experimental Investigations ◽  
Wind Turbine Blades

Experimental investigations of wind turbine blades having NACA airfoils 0021 and 4412 with and without tubercles on the leading edge have been performed in a wind tunnel. It was found that the lift coefficient of the airfoil 0021 with tubercles was higher at Re = 1.2×105 and 1.69×105 in post critical region (at higher angle of attach) than airfoils without tubercles but this difference relatively diminished at higher Reynolds numbers and beyond indicating that there is no effect on the lift coefficients of airfoils with tubercles at higher Reynolds numbers whereas drag coefficient remains unchanged. It is noted that at Re = 1.69×105, the lift coefficient of airfoil without tubercles drops from 0.96 to 0.42 as the angle of attack increases from 15° to 20° which is about 56% and the corresponding values of lift coefficient for airfoil with tubercles are 0.86 and 0.7 at respective angles with18% drop.

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.

Predicting fiber drag coefficient and settling velocity of sphere in fiber containing Newtonian fluids

2017 ◽  
Vol 159 ◽  
pp. 409-418 ◽  
Author(s):  
Zhengming Xu ◽  
Xianzhi Song ◽  
Gensheng Li ◽  
Qingling Liu ◽  
Zhaoyu Pang ◽  
...  
Keyword(s):  
Drag Coefficient ◽  
Settling Velocity ◽  
Newtonian Fluids
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