title: Simulations of transonic shock-tube flow with a model micro-cylinder in the driver.
abstract: A unique hand-held needle-free powder injection system, using a transient shock-tube flow to deliver powder genes and drugs into human skin for a wide range of treatments, has been proposed. In the development of such devices, a strong non-linear phenomenon, possibly shock process instead of unsteady expansion waves, was observed in the driver portion of the shock-tube flow in the presence of a gas micro-cylinder. In this paper, we further investigate effects of a model micro-cylinder in the driver on the gas dynamics of a prototype clinical device numerically. To accurately simulate such complex shock-tube flows, an efficient numerical solver, MIFVS, is extended to incorporate with a transition-modified turbulence model. Comparison with experimental measurements shows that the extended MIFVS accurately predicts pressure traces in both laminar and turbulent regimes. The separation zone due to a strong non-linear process is properly captured via such transition-modified turbulence model. Numerical investigations and discoveries are presented and discussed.
authors.affiliation: School of Mechanical Engineering, Southern Yangtze University, 1800 Lihu Road, Wuxi, Jiangsu Province 214122, PR China. yi.liu@eng.ox.ac.uk
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Mark A F
authors.initials: MA
authors.lastname: Kendall
mesh_terms: D016503:Drug Delivery Systems / Q000295:instrumentation*; D004867:Equipment Design; D006801:Humans; D007268:Injections, Epidural / Q000295:instrumentation; D015233:Models, Statistical; D011208:Powders; D014465:Ultrasonics
chemical_list: D011208:Powders