Zhongquan Charlie Zheng

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A modified immersed-boundary method is developed using the direct-forcing concept. An improved bilinear interpola-tion/extrapolation algorithm is implemented for more accurate boundary forcing expressions and easier implementation. Detailed discussions of the method are presented on the stability, velocity interpolation on the immersed boundary,(More)
SUMMARY Smoke reduction processes in an indoor room-scale chamber are generated by injecting nanoparticle aggregates. A numerical model, with a flow solver implemented with a particle collision model, is used to simulate the smoke-reduction effect. The collision model, developed particularly for simulating collisions among particles with significantly(More)
The goal of this study is to develop a more realistic human thermal model. Previous models have been based on simple cylindrical geometries. The current study uses shaped and refined body segments to simulate heat and mass transfer in the human body during a transient process. The body segments and blood vessels (or respiratory tract) were discretized into(More)
SUMMARY A thin-tube vortex method is developed to investigate the intrinsic instability within a counter-rotating vortex pair system and the eeects from the core size and the wavenumbers (or wavelengths). The numerical accuracy and the advantages of the scheme are theoretically estimated. A nearest-neighbour-image method is employed in this(More)
Nonlinear responses to a transversely oscillating cylinder in the wake of a stationary upstream cylinder are studied theoretically by using an immersed-boundary method at Re= 100. Response states are investigated in the three flow regimes for a tandem-cylinder system: the " vortex suppression " regime, the critical spacing regime, and the " vortex formation(More)
In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: a b s t r a c t An Euler-type gas/particle two-phase flow numerical model is presented(More)
A time-domain solver using an immersed boundary method is investigated for simulating sound propagation over porous and rigid barriers of arbitrary shapes. In this study, acoustic propagation in the air from an impulse source over the ground is considered as a model problem. The linearized Euler equations are solved for sound propagation in the air and the(More)
Oscillating foil machines represent a type of flow energy harvesters which perform pitching and plunging motions simultaneously to harness the energy from incoming stream. In this paper, a new adaptive deformation oscillating wing was proposed and the theoretical performance of such a concept was studied here through unsteady two-dimensional simulations(More)