• Title/Summary/Keyword: Aerodynamic characteristics

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Development of Modeling and Simulation Tool for the Performance Analysis of Pods Mounted on Highly Maneuverable Aircraft (고기동 항공기 탑재 파드 성능 분석을 위한 모델링 및 시뮬레이션 도구 개발)

  • Lee, Sanghyun;Shin, Jinyoung;Lee, Jaein;Kim, Jongbum;Kim, Songhyon;Kim, Sitae;Cho, Donghyurn
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.50 no.7
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    • pp.507-514
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    • 2022
  • The EO/IR targeting pod mounted on a fighter to acquire information about tactical targets is typically mounted and operated at the bottom of the aircraft fuselage. Since the aircraft equipped with such an external attachment has complexed aerodynamic and inertial characteristics compared to the aircraft flying without an external attachment, a method of system performance analyses is required to identify development risk factors in the early stages of development and reflect them in the design. In this study, a development plan was presented to provide the necessary modeling and simulation tools to develop a pod that can acquire measurement data stably in a highly maneuverable environment. The limiting operating conditions of the pods mounted on the highly maneuverable aircraft were derived, the aerodynamics and inertial loads of the mounted pods were analyzed according to the limiting operating conditions, and a flight data generation and transmission system were developed by simulating the mission of the aircraft equipped with the mounted pods.

Comparison of the Characteristics of 16 Commercial Nebulizer/Compressor Combinations Used in Korea (국내 시판되는 16가지 연무기/압축기의 성능 평가)

  • Kim, Hyun Jung;Lee, Cho Ae;Hwang, Eun Kyung;Han, Man Young;Ann, Uk Sung;Cho, Young Min
    • Clinical and Experimental Pediatrics
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    • v.46 no.12
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    • pp.1235-1241
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    • 2003
  • Purpose : We assessed the dynamic characteristics of 16 nebulizer/compressor combinations currently available in Korea. Methods : The 16 nebulizer/compressor combinations(Pariboy Type 38/Long life, Pariboy Type N/Long life, Pariboy Type N/Salter 8900, Pariboy Type N/LC, Devilbiss pulmoaid-LT/Hudson, Devilbiss pulmoaid/Hudson, Mesmed neb-300/Own, San-up 3040/Hudson, Midas(Basic)/Own, AirJolie 2/Hudson, Thomas 1127/Salter 8900, Noel NE-2000/Salter 8900, Omron CX3/Hudson, Chang Woo CWN-100/Salter 8900, Voyage/Mefar, Chang Woo ASI-Pro/Medel jet pulse) were evaluated in terms of particle size and mass output. In addition, we determined the effects of nebulizer fill volume on mass output. Results : Pariboy Type N/Long life has the highest respirable mass of 0.184 mg/min and Mesmed Neb-300/Own has the lowest 0.019 mg/min. Pariboy Type N/Long life has the highest mass output of 0.68 mg/min and the shortest mass median aerodynamic diameter(MMAD) of $3.76{\mu}m$. All combinations other than Pariboy Type N/Long life produced a MMAD of over $5{\mu}m$. MMAD over a 5 min nebulization ranged 3.76 to $9.83{\mu}m$. There were no significant effects of fill volume on mass output. Conclusion : We concluded that there is a wide variation in performance of nebulizer/compressor combinations. The characteristics of nebulizer/compressor combinations should be considered in selecting products.

A Comparison Study of Aerosol Samplers for PM10 Mass Concentration Measurement (PM10 질량농도 측정을 위한 시료채취기의 비교 연구)

  • Park, Ju-Myon;Koo, Ja-Kon;Jeong, Tae-Young;Kwon, Dong-Myung;Yoo, Jong-Ik;Seo, Yong-Chil
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.2
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    • pp.153-160
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    • 2009
  • A PM10 (aerodynamic diameter${\leq}$10 ${\mu}m$) sampler is used to quantify the potential human exposure to suspended particulate matter (PM) and to comply with the governmental regulation. This study was conducted to compare and evaluate the same PM10 cutpoint and different slopes between United States Environmental Protection Agency (USEPA) PM10 sampling criterion and American Conference of Governmental Industrial Hygienists/$Comit\acute{e}$ $Europ\acute{e}en$ de Normalization/International Organization for Standardization thoracic PM10 sampling criterion through theory and experiment. Four PM10 samplers according to the USEPA criterion and one RespiCon sampler in accordance with the thoracic PM10 criterion were used in the present study. In addition, one DustTrak monitor was used to measure real time PM10 mass concentrations. All six aerosol samplers were tested in a PM generation chamber using polydisperse fly ash. Theoretical mass concentrations were calculated by applying the measured particle size distribution characteristics (geometric mean = 6.6 ${\mu}m$, geometric standard deviation = 1.9) of fly ash to each sampling criterion. The measured mass concentrations through a chamber experiment were consistent with theoretical mass concentrations in that a RespiCon sampler with the thoracic PM10 criterion collected less PM than a PM10 sampler with the USEPA criterion. The overall chamber experiment results indicated, when a PM10 sampler was used as a reference sampler, that (1) a RespiCon sampler had a normalizing factor of 1.6, meaning that this sampler underestimated an average 60% of PM10 mass sampled from a PM10 sampler, and (2) a DustTrak real-time monitor using a PM10 inlet had a calibration factor of 2.1.