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Study on drug powder acceleration in a micro shock tube
Guang Zhang,Yingzi Jin,Toshiaki Setoguchi,Heuy Dong Kim 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.9
Recently, micro shock tubes have been widely used in the medical engineering. The needle-free drug delivery device which mainly consists of a micro shock tube and an expanded nozzle has been produced to inject drug powders into human and animal bodies without any sharp metal needles. The drug powders were delivered by obtaining high momentum, which can be done by accelerating drug powders in the micro shock tube and supersonic nozzle. The particle-gas flows are induced by the incident shock wave developing by rupturing the diaphragm in the micro shock tube and again accelerated in the supersonic nozzle. The momentum of injected drug particles should be strictly controlled otherwise patients will suffer from skin injury or hurt. Even though micro shock tubes have been investigated in the past several decades, the detailed studies on particle-gas flows in the micro shock tube were rare to date due to the micro size and difficult experimental operation on micro shock tubes. In this paper, the experimental and numerical studies were carried out on investigating particle-gas flows in a designed micro shock tube. Particle tracking velocimetry (PTV) was performed to calculated particle average velocity at the exit of the supersonic nozzle. The nozzle flows were analyzed by obtaining instantaneous particle fields. The particle number density ratio was also investigated in the test section. The numerical simulations were performed by calculating unsteady Naver-Stokes equations on compressible flows and using fully implicit finite volume schemes. Discrete phase model (DPM) was used for simulating particle-gas flows in the micro shock tube. Particle diameter and density were varied to investigate their effects on the particle-gas flows. Unsteady particle-gas flows and shock wave propagation were obtained in details in the micro shock tube for present experimental and numerical studies.
Numerical simulation on characteristics of particle-gas flows in supersonic impinging jet
Heuy Dong Kim(김희동),Guang Zhang,Yingzi Jin,Toshiaki Setoguchi 한국가시화정보학회 2016 한국가시화정보학회 학술발표대회 논문집 Vol.2016 No.4
The supersonic impinging jets always occur when crafts are starting short takeoff and vertical landing from the ground. The adverse flow conditions happen to decrease the performance of aircrafts, such as impinging force, high noise spectrum and high shear stresses. Due to rare results on particle-gas impinging jet flows to date, numerical simulations were performed to investigate the supersonic impinging jet flows of particle-gas two phases in the present studies. Convergent-divergent supersonic and convergent sonic nozzles were used to induce the supersonic jet flows. Discrete phase model (DPM) was used to simulate the particle-gas flows. Different particle diameters were investigated. The flow Mach number and pressure coefficients on the ground surface were obtained to describe phenomena inside impinging and wall jet flows. The particle motion was obtained in details from the present simulations.