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Your search keyword '"Pei, Junxian"' showing total 3 results
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3 results on '"Pei, Junxian"'

1. Numerical study of the flow around a hyperbolic cylinder at Reynolds number 3900.

Author

Luo, Jia-Ling, Pei, Junxian, Yan, Yan, and Wang, Wen-Quan

Subjects
*REYNOLDS number, *DRAG coefficient, *DRAG reduction, *HYPERBOLOID structures, *FLUID flow, *DRAG force, *VORTEX shedding
Abstract

In this paper, a numerical computation method combining a high-order compact difference scheme and immersed boundary method is used to simulate the flow around a hyperbolic cylinder with different aspect ratios and eccentricity. It is found that compared to the circular cylinder, the vortex-separation point in the wake of the hyperbolic cylinder moves backward, and the corresponding drag coefficient decreases by 27.6%. More interestingly, the time-averaged drag coefficient of hyperbolic cylinder behaviors parabolic relationship with cross-section aspect ratio and hyperboloid eccentricity, respectively. As the aspect ratio decreases from 1 to 0.6, the flow drag parallel to the long-axis reduces dramatically to 42.9%. Especially, there is no obviously low pressure region behind the hyperbolic cylinder when r = 0.4, which leads to the drag coefficient is only 0.0249 and close to zero. Besides, the average drag coefficient diminishes in a parabolic trend with the eccentricity that has a monotonously positive correlation with two parameters, and an increase in eccentricity e by varying a or c will also reduce the drag, but the effect of parameter a is more obvious than parameter c. The results presented here are expected to suggest a strategy for drag reduction in flow around the cylinder and provide theoretical guidance for the design and optimization of hyperbolic structures in flowing fluid. •Flow over a hyperbolic cylinder with different aspect ratio and eccentricity is investigated •Drag coefficient of hyperbolic cylinder decreases by 27.6% compared to circular cylinder; •Time-averaged drag has a parabolic relationship with the aspect ratio and eccentricity [ABSTRACT FROM AUTHOR]

Published
2022
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2. A numerical study on elliptical particle deposition with an immersed boundary-lattice Boltzmann method.

Author

Wang, Wen-Quan, Wang, Jinling, Cui, Guanzhe, Pei, Junxian, and Yan, Yan

Subjects
*ANGULAR velocity, *POISEUILLE flow, *SHEAR flow, *REYNOLDS number, *MOTION, *VELOCITY, *HAMILTONIAN systems
Abstract

• Angular velocity of particle has same direction whatever flow conditions or Reynolds number. • Average deposition velocity and the aspect ratio present a closing parabola curve. • Initial angle only changes the phase angle of the dynamic characteristic curve. • Density ratio has a distinct and positive relationship with the settling velocity. This paper presents a numerical study on elliptic particle deposition in a Newtonian fluid at low Reynolds numbers. The effects of inflow condition, Reynolds number, aspect ratio, initial angle, and density ratio on the dynamic characteristics of the particle are investigated. The results show that the absolute deposition velocity of the particle increases with the decrease of Reynolds number for all flow conditions. Although there is a slight difference between the uniform and the Poiseuille flows, the absolute deposition and angular velocities of the particle are enhanced by the shear flow. Moreover, the deposition, horizontal and angular velocities exhibit a periodic fluctuation with the dependent frequency of the inflow conditions and the Reynolds numbers. The relationship between the time-averaged deposition velocity and the aspect ratio presents a closing quadratic curve. The initial angle of the particle only affects the phase difference of motion but not changes the dynamic characteristics of the particle. Furthermore, the time-averaged deposition velocity of the particle is proportional to the density ratio. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
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3. A numerical study on elliptical particle deposition with an immersed boundary-lattice Boltzmann method.

Author

Wang, Wen-Quan, Wang, Jinling, Cui, Guanzhe, Pei, Junxian, and Yan, Yan

Subjects
*ANGULAR velocity, *POISEUILLE flow, *SHEAR flow, *REYNOLDS number, *MOTION, *VELOCITY, *HAMILTONIAN systems
Abstract

• Angular velocity of particle has same direction whatever flow conditions or Reynolds number. • Average deposition velocity and the aspect ratio present a closing parabola curve. • Initial angle only changes the phase angle of the dynamic characteristic curve. • Density ratio has a distinct and positive relationship with the settling velocity. This paper presents a numerical study on elliptic particle deposition in a Newtonian fluid at low Reynolds numbers. The effects of inflow condition, Reynolds number, aspect ratio, initial angle, and density ratio on the dynamic characteristics of the particle are investigated. The results show that the absolute deposition velocity of the particle increases with the decrease of Reynolds number for all flow conditions. Although there is a slight difference between the uniform and the Poiseuille flows, the absolute deposition and angular velocities of the particle are enhanced by the shear flow. Moreover, the deposition, horizontal and angular velocities exhibit a periodic fluctuation with the dependent frequency of the inflow conditions and the Reynolds numbers. The relationship between the time-averaged deposition velocity and the aspect ratio presents a closing quadratic curve. The initial angle of the particle only affects the phase difference of motion but not changes the dynamic characteristics of the particle. Furthermore, the time-averaged deposition velocity of the particle is proportional to the density ratio. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

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