Zhongquan Charlie Zheng

Learn More
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)
  • Z Zheng
  • 2000
This study examines the delay between first marriage and first live birth in China among a sample of women who married between 1980 and 1992. Most couples in China only use contraception after the first child is born. Most sample women had their first child within 2 years of marriage. However, there are significant rural-urban differences in the first birth(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 Fish are good examples of pressure sensing animals. In this paper,(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)
In order to study the capability of computational methods in investigating the mechanisms associated with disease and contaminants transmission in aircraft cabins, the computational fluid dynamics (CFD) models are used for the simulation of turbulent airflow and tracer gas diffusion in a generic aircraft cabin mockup. The CFD models are validated through(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)