Experiments on the lift of a spinning sphere in a range of intermediate Reynolds numbers

“…Where p A is the projected area of the particle; D C is the drag coefficient which is dependent on the local Reynolds Re [10] . Particles in the vertical direction mainly affected by gravity and fluid drag force [11] :…”

Section: Particle Movement Modelmentioning

confidence: 99%

Dynamic Contamination Simulation Analysis of Insulators using coupled DEM and CFD methods

Wang¹,

Sun²,

Deng³

et al. 2016

dteees

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Abstract. In order to study the dynamic contamination characteristics of the bar insulator surface, the particle movement in flow field, the contact and adhesion stage between particles and insulator were simulated using coupled DEM and CFD methods. The van der Waals forces and liquid bridge force of adhesion were considered while the contamination stage is visual, then established the dynamic contamination model, proposed the polluting area rate and the adhesion rate to analyze the pollution situation influenced by the particle diameter, the wind speed and the coming angle. The research result shows that in a certain period of time, the polluting area rate is linear. The follow-up nature are better when the diameter is smaller than 20μm, then they primarily deposit on the lower surface through drag forces; Particles larger than 60μm, mainly deposited on the upper surface through gravity sedimentation; with the increasing of wind speed, the adhesion rate increases linearly. When the wind speed is 10m/s, the adhesion rate reached the maximum. When the wind speed is 10 m/s and up, the adhesion rate gradually decline, and the desorption will happen more seriously. When the coming angle is about 135 degree, the adhesion rate is maximum. With the change of the coming angle, the possibilities of secondary collision is increased which will increase the pollution of the lower surface.

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“…For C D , Henderson relations [7] were used. For calculating C ω , the exact solution obtained by Rubinow and Keller [8] was used as well as the formula suggested by Oesterl‚ e and Bui Dinh [9]. The expression for C L was taken in the form suggested by Dennis et al [10].…”

Section: Modeling Of Particle-phase Flowmentioning

confidence: 99%

Effects of particle mixing and scattering in the dusty gas flow through moving and stationary cascades of airfoils

Tsirkunov

Romanyuk

Panfilov

2011

Progress in Propulsion Physics

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Time-dependent two-dimensional (2D) §ow of dusty gas through a set of two cascades of airfoils (blades) has been studied numerically. The ¦rst cascade was assumed to move (rotor) and the second one to be immovable (stator). Such a §ow can be considered, in some sense, as a §ow in the inlet stage of a turbomachine, for example, in the inlet compressor of an aircraft turbojet engine. Dust particle concentration was assumed to be very low, so that the interparticle collisions and the e¨ect of the dispersed phase on the carrier gas were negligible. Flow of the carrier gas was described by full Navier Stokes equations. In calculations of particle motion, the particles were considered as solid spheres. The particle drag force, transverse Magnus force, and damping torque were taken into account in the model of gas particle interaction. The impact interaction of particles with blades was considered as frictional and partly elastic. The e¨ects of particle size distribution and particle scattering in the course of particle blade collisions were investigated. Flow ¦elds of the carrier gas and §ow patterns of the particle phase were obtained and discussed.

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Experiments on the lift of a spinning sphere in a range of intermediate Reynolds numbers

Cited by 249 publications

References 8 publications

A novel combined model of discrete and mixture phases for nanoparticles in convective turbulent flow

A novel combined model of discrete and mixture phases for nanoparticles in convective turbulent flow

Dynamic Contamination Simulation Analysis of Insulators using coupled DEM and CFD methods

Effects of particle mixing and scattering in the dusty gas flow through moving and stationary cascades of airfoils

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