scholarly journals Viscous drag force model for dynamic Wilhelmy plate experiments

2019 ◽  
Vol 4 (8) ◽  
Author(s):  
Peter Zhang ◽  
Kamran Mohseni
Keyword(s):  
Drag Force ◽  
Viscous Drag ◽  
Force Model ◽  
Wilhelmy Plate ◽  
Viscous Drag Force

The numerical study of viscous drag force influence on low-frequency surge motion of a semi-submersible in storm sea states

2020 ◽  
Vol 213 ◽  
pp. 107511 ◽  
Author(s):  
Shan Ma ◽  
De-kang Xu ◽  
Wen-yang Duan ◽  
Ji-kang Chen ◽  
Kang-ping Liao ◽  
...  
Keyword(s):  
Drag Force ◽  
Numerical Study ◽  
Low Frequency ◽  
Viscous Drag ◽  
Viscous Drag Force

scholarly journals Dynamics of photo-ablated carbon plasma in an inert gas atmosphere

1998 ◽  
Vol 16 (1) ◽  
pp. 31-38 ◽  
Author(s):  
T. Kerdja ◽  
S. Abdelli ◽  
E. H. Amara ◽  
D. Ghobrini ◽  
M. Si-Bachir ◽  
...  
Keyword(s):  
Wave Model ◽  
Inert Atmosphere ◽  
Viscous Drag ◽  
Laser Evaporation ◽  
Force Model ◽  
Plasma Dynamics ◽  
Gas Atmosphere ◽  
Viscous Drag Force ◽  
Swan Band ◽  
Two Stages

Time and space-resolved emission spectroscopy measurements were performed to investigate plasma dynamics during laser evaporation of a graphite target in an ambient inert atmosphere. Intense molecular emission is found to occur behind a front separating the plasma from the foreign gas. Two stages of expansion are found and are well described, using a viscous drag force model for the first one and a delayed ideal blast wave model for the second. The vibrational temperature estimated using the Swan band in helium at different pressures is presented.

scholarly journals Исследование реакции поверхности жидкости на импульсное воздействие наклонной газовой струи при малых числах Рэйнольдса

2022 ◽  
Vol 92 (2) ◽  
pp. 216
Author(s):  
А.П. Савенков ◽  
В.А. Сычёв
Keyword(s):  
Drag Force ◽  
Liquid Surface ◽  
Dynamic Properties ◽  
Liquid System ◽  
Gas Jet ◽  
Viscous Drag ◽  
Phase System ◽  
Two Phase ◽  
Automatic Control Theory ◽  
Viscous Drag Force

A mathematical description of the motion of a cavity on the liquid surface under an oblique action of a gas jet is obtained using the well-known expressions for the movement of a gas bubble in a liquid. The boundary of the viscous drag force domination over the form drag force is determined. The impingement of the gas jet on the liquid surface is considered as a dynamic object of the automatic control theory. It is found that the dynamic properties of the two-phase system "gas jet - liquid" are described by the integrator equations. Using a specially designed setup, the transient response of the "gas jet - liquid" system were experimentally obtained for the aerodynamic action at angles of 20º and 50º to the surfaces of liquids with the viscosities of 0.71 and 26.1 Pa•s (Reynolds number Re < 2). The research results are necessary for the analysis of the non-contact aerodynamic method of liquid viscosity measurements.

The viscous drag force on a spherical bubble with a time-dependent radius

1998 ◽  
Vol 10 (3) ◽  
pp. 550-554 ◽  
Author(s):  
Jacques Magnaudet ◽  
Dominique Legendre
Keyword(s):  
Drag Force ◽  
Time Dependent ◽  
Viscous Drag ◽  
Spherical Bubble ◽  
Viscous Drag Force

Structures of a Magnetorheological Fluid

2001 ◽  
Vol 15 (06n07) ◽  
pp. 851-858 ◽  
Author(s):  
G. L. Gulley ◽  
R. Tao
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Drag Force ◽  
Liquid State ◽  
Magnetorheological Fluid ◽  
Viscous Drag ◽  
Viscous Drag Force ◽  
Brownian Force ◽  
Dynamics Simulations ◽  
Two Parameters

Molecular dynamics simulations were carried out to find the underlying structures of a Magnetorheological (MR) fluid while taking into account dipolar forces, viscous drag, and the Brownian force. Three different structures were found: the bct lattice, chains, and a liquid state. The conditions under which these structures are found is based on two parameters A and B which are the ratios of the dipolar force to the viscous drag force and the Brownian force to the dipolar force respectively.

Dark Matter: Could It Be Vacuum Viscosity?

2020 ◽  
Vol 13 (1) ◽  
pp. 47-57
Keyword(s):  
Dark Matter ◽  
Simple Model ◽  
Drag Force ◽  
Spiral Galaxies ◽  
Viscous Drag ◽  
Rotation Curves ◽  
The Galaxy ◽  
Viscous Drag Force ◽  
Matter Effect ◽  
Good Agreement

We test a hypothesis that stars located away from the center of the galaxy, moving under the effect of an emergent viscous drag force perpendicular to their velocities, might exhibit the behavior observed in the rotation curves of the spiral galaxies. We construct a simple model for such an assumption, then by using simple fitting technique, we are able to produce the rotation curves for a sample of 18 spiral galaxies. Results show good agreement with the observed rotation curves. The applicability of our hypothesis suggests that an emergent drag force perpendicular to the velocity of the stars might be the cause of the apparent dark matter effect.

scholarly journals Evaluation of the Performance of the Drag Force Model in Predicting Droplet Evaporation for R134a Single Droplet and Spray Characteristics for R134a Flashing Spray

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4618
Author(s):  
Zhi-Fu Zhou ◽  
Dong-Qing Zhu ◽  
Guan-Yu Lu ◽  
Bin Chen ◽  
Wei-Tao Wu ◽  
...  
Keyword(s):  
Drag Force ◽  
Droplet Diameter ◽  
Radial Distance ◽  
Droplet Evaporation ◽  
Nozzle Diameter ◽  
Force Model ◽  
Straight Tube ◽  
Single Droplet ◽  
Spray Characteristics ◽  
Two Phase

Drag force plays an important role in determining the momentum, heat and mass transfer of droplets in a flashing spray. This paper conducts a comparative study to examine the performance of drag force models in predicting the evolution of droplet evaporation for R134a single droplet and spray characteristics for its flashing spray. The study starts from single moving R134a droplet vaporizing in atomispheric environment, to a fully turbulent, flashing spray caused by an accidental release of high-pressure R134a liquid in the form of a straight-tube nozzle, using in-house developed code and a modified sprayFoam solver in OpenFOAM, respectively. The effect of the nozzle diameter on the spray characteristics of R134a two-phase flashing spray is also examined. The results indicate that most of the drag force models have little effect on droplet evporation in both single isolated droplet modelling and fully two-phase flashing spray simulation. However, the Khan–Richardson model contributes to different results. In particular, it predicts a much different profile of the droplet diameter distribution and a much lower droplet temperature in the radial distance. The nozzle diameter has a significant impact on the flashing spray. A smaller diameter nozzle leads to more internse explosive atomization, shorter penetration distance, lower droplet diameter and velocity, and a faster temperature decrease.

A Method to Double the Extension Ability of Radial Jet Drilling Technology

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Li Jingbin ◽  
Zhang Guangqing ◽  
Li Gensheng ◽  
Huang Zhongwei ◽  
Li Weichang
Keyword(s):  
Drag Force ◽  
Average Velocity ◽  
Oil And Gas ◽  
Damage Zone ◽  
Force Model ◽  
Gas Recovery ◽  
Drainage Radius ◽  
Velocity Flow ◽  
Critical Issues ◽  
Drilling Technology

Radial jet drilling (RJD) technology is an effective method to enhance oil and gas recovery by penetrating the near-wellbore damage zone, and increasing the drainage radius greatly. Recently, it is identified as a potential technology to develop the geothermal energy. But the extension ability, one of the most critical issues of the RJD, is limited. Because only high pressure flexible hose (HPFH), which is hard to be fed in and subjected to greater resistance by the diverter, can be used as the drill stem to turn from vertical to horizontal in the casing. In this paper, an innovative method to feed in the HPFH by the drag force generated by high velocity flow in narrow annulus is proposed. The drag force model is built, validated, and modified by theoretical and experimental ways. Results show that the resulting drag force, which is equivalent to the self-propelled force, can easily achieve and feed in the HPFH. There is a power law relationship between the drag force and the average velocity; the drag force increases linearly with the length of the narrow annulus. Higher average velocity and 1–1.5 m annulus length are recommended. According to force analysis, the extension ability of the RJD can be doubled theoretically by this method. The results of this paper will greatly promote the development of RJD technology.

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