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)
Lipofectin-mediated gene transfer was used to introduce plasmid harboring the tyrosine hydroxylase (TH) gene into the striatum of rats with lesions of the nigrostriatal pathway. The rotational asymmetry of Parkinson disease model rat was reduced quickly and significantly, suggesting that plasmid-DNA-transfected brain cells can generate L-dopa locally in the(More)
A vortex method model developed previously for studying the mechanisms in vortex/shear-layer interactions has been validated with large-eddy turbulence simulations by Proctor et al. Two Dimensional Wake Vortex Simulations in the Atmosphere: Preliminary Sensitivity Studies, " AIAA Paper 97-0056, Jan. 1997) and eld measurement data. A shear-detection(More)
A collision model, modified from the Smoluchowski model, is developed for simulating coagulation and growth of a large number of aerosol particles with significantly different sizes. In this collision model, the particle-size distribution is discretized in volume bins, and the total mass among all the bins is conserved. In situations with significantly(More)
The purpose of the study is to investigate the wind noise reduction provided by microphone windscreens at different frequencies of the impinging turbulence. The windscreen is assumed to be a cylindrically shaped porous medium. This paper uses a high-order scheme to improve the accuracy at the interface between air and porous medium. The computational scheme(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)