• Title/Summary/Keyword: particle injection

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New Process for Ti Alloy Powder Production by Using Gas Atomization

  • Fujita, Makoto;Arimoto, Nobuhiro;Nishioka, Kazuo;Miura, Hideshi
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.12-13
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    • 2006
  • The spherical and high quality Titanium fine powder "Tilop" has been produced with gas atomization furnace, Sumitomo Titanium Corporation originally designed. Recently, a new process which can produce Ti-alloy(Ti-6Al-4V) powders by utilizing our gas atomization process, of which raw material is sponge titanium pre-mixed with alloy chips or granules has been also developed. The particle size of gas atomized Ti-alloy powder and the mechanical properties of sintered Ti-alloy compacts prepared by metal injection molding were discussed in this study.

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Effect of Ambient Conditions on Spray Behavior of Gasoline Injector (가솔린 분무 거동에 미치는 분위기 조건의 영향)

  • 이창식;이기형;최수천;권상일
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.2
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    • pp.27-32
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    • 2000
  • The main objective of this work is to investigate the effect of ambient conditions on the spray behavior and spray characteristics of high-pressure fuel injector. For this purpose, the effects of ambient pressure and temperature on the spray characteristics have been studied by applying the analysis of visualization system and phase Doppler particle analyzer. In this experiment, the visualization of spray behavior was performed under various ambient gas conditions and injection parameters such as gas temperature, ambient pressure, injection pressure of injector, and axial distance from the nozzle tip. Based on the investigation results, the spray tip penetration and spray width decrease with the increase of ambient gas pressure in the spray chamber. The effects of the spray parameters on the microscopic characteristics of gasoline spray were discussed.

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Genotoxic Effects of Diesel Emission Particle Extract, $HgCl_2$ and $Pb(Ac)_2$ by the Mouse Bone Marrow Micronucleus Test (마우스 골수 소핵 시험에 의한 디젤분진, $HgCl_2$$Pb(Ac)_2$의 유전독성효과)

  • 허문영;최성규;유기선;손동헌
    • Journal of Korean Society for Atmospheric Environment
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    • v.5 no.1
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    • pp.62-67
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    • 1989
  • The clastogenic effects of the diesel emission particle extract (DEPE), mercuric chloride and lead acetate were examined by the mouse bone marrow micronucleus test. DEPE had a potent clastogenic effect by intraperitoneal injection with dose-response between 100 and 300mg/kg b.w.. Mercuric chloride and lead acetate also gave a clastogenic effects but mercuric chloride only had a dose-response between 1 and 3mg/kg b.w.. When DEPE was administrated with mercuric chloride or lead acetate, the frequency of micronucleated cells was slight but not significant increase in comparision to a single treatment with DEPE alone.

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Experimental study on the Formation and Growth of Silica Particles in $H_2/O_2$ Diffusion Flame by Electro-Spraying Method and Evaporation ($H_2/O_2$확산화염에서 전기수력학적 방법과 증발기에 의해 발생된 입자의 성장 비교에 관한 실험적 연구)

  • Sohn, S.H.;Yook, S.J.;Ah, K.H.;Choi, M.S.
    • Proceedings of the KSME Conference
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    • 2000.11b
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    • pp.168-173
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    • 2000
  • Flame aerosol synthesis technology refers to the formation of fine particles from gases in flame and is widely used in practical materials processing. In this paper, an experimental investigation was performed on growth of the silica particles that were generated in $H_2/O_2$ Diffusion Flame by the direct injection or TEOS using Electro-spraying method. in this flame aerosol synthesis, four main parameters or nos interaction (flame temperature, residence time or particle in flame, TEOS flow rate, applied voltage) for particle generation and growth was investigated along the axial direction above the burner. A fairly monodisperse non-aggregated particles were successfully obtained.

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Effect of Reinforcements on Dynamic Elastic Modulus of Polyethylene Matrix Composite Materials (폴리에틸렌기지 복합재료의 동적탄성계수에 대한 강화재의 효과)

  • 김경섭;정현규;홍순형
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 1999.11a
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    • pp.1-4
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    • 1999
  • The attenuation coefficients of SiC particle reinforced low-density polyethylene (LDPE) matrix composites were measured by pulse echo method and dynamic elastic measure method with varying the volume fraction of SiC particle ranged from 0% to 40% and the size of SiC particles ranged from 0.8$\mu$m to 48$\mu$m. The SiCp/LDPE composites were fabricated with the melt injection process and the fabricated composites showed almost full density above 99% up to 40vo1% SiCp reinforcements. The attenuation constant of LDPE measured by dynamic elastic constant had same result with that measured by pulse echo method, but the attenuation constant of SiCp/LDPE measured by dynamic elastic constant did not have same result with that measured by pulse echo method.

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Corona ion Assisted Nano-Particle Morphology Control in an Atmospheric Pressure Furnace Reactor (대기압 반응로 내 코로나 이온을 이용한 나노입자 형상의 제어)

  • An, Gang-Ho;Yun, Jin-Uk;Kim, Yeong-Won
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.5
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    • pp.710-715
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    • 2002
  • The spherical nonagglomerated and uniform nanometer-size SiO$_2$particles are synthesized by the injection of TEOS vapor, irons and reaction gas in a furnace. Ions are generated by corona discharge and these ions charge SiO$_2$particles. As a result, spherical, nonagglomerated and ultrafine particles are generated in various conditions. Their morphology, charging portion and size distribution are examined by using TEM, ESP and SMPS. As the applied voltage of electrode changes from 0 to 5.0 kV, it is observed that the melon diameter of SiO$_2$particle decreases from 94 nm to 42 nm.

Numerical Investigation of a Steady Non-Evaporating Hollow-Cone Spray Interacting with an Annular Air Jet (정상 할로우 콘 분무와 환형 공기 제트의 상호작용에 관한 수치적 연구)

  • Kim, Woo-Tae;Huh, Kang-Y.
    • Journal of ILASS-Korea
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    • v.5 no.2
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    • pp.43-52
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    • 2000
  • Numerical simulation of steady, non-evaporating hollow-cone sprays interacting with concentric annular air jets is performed using the discrete stochastic particle method in KIVA. The spray characteristics such as SMD, mean droplet velocity, liquid volume flux, air/liquid mass ratio, and droplet number density arc obtained and compared with the measurements involving different air flow rates in large and small annuli. Overall satisfactory agreement is achieved between calculation and experiment except for the deviation in the downstream SMD arising from uncertainty in the size distribution function at injection, and inaccuracy in the averaged spray parameters due to the small volumes of axisymmetric 2-D sector meshes close to the axis.

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Flow Visualization Study around the Distributor of Plate-fin Heat Exchangers (판형-핀 열교환기 분배면의 유동 가시화 연구)

  • Jeong, Tae-Sik;Park, Seung-Ha;Kim, Chang-Su;Kim, Hyoung-Bum
    • Journal of the Korean Society of Visualization
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    • v.10 no.3
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    • pp.37-41
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    • 2012
  • Plate-fin heat exchanger is a kind of compact heat exchangers with a good performance in heat transfer. It is widely used in various engineering fields such as aerospace, chemical and biomedical industries. Quantitative and qualitative flow visualization study were performed using the water model of commercial plate-fin heat exchanger with header angles of $30^{\circ}$. The Reynolds number was 100. Conventional digital particle image velocimetry was used to measure the instantaneous velocity fields of the header region and the flow visualization using dye injection and hydrogen bubble method were applied to capture the qualitative flow characteristics. The results showed the existence of separation flow region at the junction area and the bottom wall of the exit region.

Fabrication of lab-on-a-chip on quartz glass using powder blasting (파우더 블라스팅을 이용한 Quartz Glass의 Lab-on-a-chip 성형)

  • Jang, Ho-su;Park, Dong-sam
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.8 no.4
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    • pp.14-19
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    • 2009
  • Micro fluid channels are machined on quartz glass using powder blasting, and the machining characteristics of the channels are experimentally evaluated. The powder blasting process parameters such as injection pressure, abrasive particle size and density, stand-off distance, number of nozzle scanning, and shape/size of the required patterns affect machining results. In this study, the influence of the number of nozzle scanning, abrasive particle size, and blasting pressure on the formation of micro channels is investigated. Machined shapes and surface roughness are measured, and the results are discussed. Through the experiments and analysis, LOC are ettectinely machined on quartz glass using powder blasting.

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COSMIC RAY ACCELERATION AT BLAST WAVES FROM TYPE Ia SUPERNOVAE

  • Kang, Hye-Sung
    • Journal of The Korean Astronomical Society
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    • v.39 no.4
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    • pp.95-105
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    • 2006
  • We have calculated the cosmic ray(CR) acceleration at young remnants from Type Ia supernovae expanding into a uniform interstellar medium(ISM). Adopting quasi-parallel magnetic fields, gasdynamic equations and the diffusion convection equation for the particle distribution function are solved in a comoving spherical grid which expands with the shock. Bohm-type diffusion due to self-excited $Alfv\acute{e}n$ waves, drift and dissipation of these waves in the precursor and thermal leakage injection were included. With magnetic fields amplified by the CR streaming instability, the particle energy can reach up to $10^{16}Z$ eV at young supernova remnants(SNRs) of several thousand years old. The fraction of the explosion energy transferred to the CR component asymptotes to 40-50 % by that time. For a typical SNR in a warm ISM, the accelerated CR energy spectrum should exhibit a concave curvature with the power-law slope flattening from 2 to 1.6 at $E{\gtrsim}0.1$ TeV.