http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 주제어 : Sonic Nozzle (검색결과 16 건)
- 무료
- 기관 내 무료
- 유료
-
Study of divergence angle influence for sonic nozzle in non-equilibrium condensation
Balasubramanian Dhandapani,이장창 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6
The condensation happens generally in a nozzle during expansion of compressed steam from convergent to the divergent part of the nozzle. The divergence angle is the angle measured from the throat of the nozzle to the outlet. In this paper, the outlet is kept constant and the throat diameter is varied. In turn, the divergence angle of the sonic nozzle is altered. The effect of divergence angle on condensation phenomena is investigated with wet steam in a sonic nozzle. For analyzing the wet steam properties, the non-equilibrium condensation model is used. This model is the classical nucleation theory coupled with the droplet growth rate equation. The base nozzle is designed with the throat diameter of 4.5 mm and other dimensions are calculated according to ASME nozzle formulas. Furthermore, the chosen divergence angles are 3°, 4.2°, and 6° for which the throat diameters are 4.5 mm, 3 mm, and 1.5 mm, respectively. As the divergence angle is gradually increased, the position of maximum Mach number of the flow moves upstream, the static temperature of the flow near the throat reaches the lower value, and the droplet nucleation rate is increased. The condensation shock gets gradually stronger with decreasing the divergence angle.
-
추력실 길이가 음속노즐을 적용한 70 N 단일액체추진제 추력기의 성능에 미치는 영향
정훈(Hun Jung),이원복(Wonbok Lee),박의용(Euiyong Park),이동원(Dongwon Lee),권태하(Taeha Kwon),서항석(Hang Seok Seo),배성훈(Seong Hun Bae),김정수(Jeong Soo Kim) 한국추진공학회 2016 한국추진공학회 학술대회논문집 Vol.2016 No.12
음속노즐을 적용한 70 N급 단일액체추진제 추력기의 추력실 길이 변화에 따른 성능특성 고찰을 위해 개발모델 추력기에 대한 지상연소시험을 수행하였다. 특성길이 2.79, 2.95, 3.13 m를 갖는 추력실 조립체가 시험변수로 적용되었으며, 추진제로는 하이드라진이 사용되었다. 본 연구의 성능비교 변수인 비추력 도출을 위한 추력, 추진제 질량유량과 함께 압력, 온도 등이 실시간으로 계측 되었다. 지상연소시험 결과, 시험조건 내에서의 추력실 길이 증가가 추력기의 주요 성능 매개변수에 부정적인 영향을 미치는 것이 식별되었다. A ground hot-firing test (HFT) was carried out to investigate the performance of 70 N-class liquid-monopropellant thruster that is assembled with sonic nozzle. Development model was evaluated on various thrust chambers having the characteristic lengths of 2.79, 2.95, and 3.13 meters and hydrazine was adopted as a propellant. Performance comparison of the test models were made through specific impulse, and thrust, propellant mass-flow rate, and chamber pressure/temperature were measured in real time. It is deduced through the HFT that the increase of the chamber length leads to a performance degradation in the test condition specified.
-
Toufik Zebbiche 한국항공우주학회 2008 International Journal of Aeronautical and Space Sc Vol.9 No.1
When the stagnation temperature of a perfect gas increases, the specific heats and their ratio do not remain constant any more and start to vary with this temperature. The gas remains perfect; its state equation remains always valid, except, it is named in more by calorically imperfect gas. The aim of this work is to trace the profiles of the supersonic axisymmetric Minimum Length Nozzle to have a uniform and parallel flow at the exit section, when the stagnation temperature is taken into account, lower than the dissociation threshold of the molecules, and to have for each exit Mach number and stagnation temperature shape of nozzle. The method of characteristics is used with the algorithm of the second order finite differences method. The form of the nozzle has a point of deflection and an initial angle of expansion. The comparison is made with the calorically perfect gas. The application is for air.
-
Zebbiche, Toufik The Korean Society for Aeronautical and Space Scie 2008 International Journal of Aeronautical and Space Sc Vol.9 No.1
When the stagnation temperature of a perfect gas increases, the specific heats and their ratio do not remain constant any more and start to vary with this temperature. The gas remains perfect; its state equation remains always valid, except, it is named in more by calorically imperfect gas. The aim of this work is to trace the profiles of the supersonic axisymmetric Minimum Length Nozzle to have a uniform and parallel flow at the exit section, when the stagnation temperature is taken into account, lower than the dissociation threshold of the molecules, and to have for each exit Mach number and stagnation temperature shape of nozzle. The method of characteristics is used with the algorithm of the second order finite differences method. The form of the nozzle has a point of deflection and an initial angle of expansion. The comparison is made with the calorically perfect gas. The application is for air.
-
-
Supersonic Dual Bell Axisymmetric Minimum Length Nozzle Conception for High Propulsion Thrust
Toufik Zebbiche 한국항공우주학회 2019 International Journal of Aeronautical and Space Sc Vol.20 No.3
The aim of this work is to develop a new numerical computing program to design a new form of a dual bell axisymmetric supersonic minimum length nozzle contour, adapted to two different altitudes, usually at sea level and space, giving a supersonic uniform and parallel flow to the exit section. The first bell has a uniform and parallel sonic inlet and a low-altitude adaptation, with a reduced supersonic Mach number, while the second bell has a supersonic inlet and uniform and parallel flow and high altitude adaptation with high supersonic Mach number. The two bells are attached to an inflection point at the exit of the first bell. The passage from low altitude to high altitude is done without any mechanical activation. The purpose of this type of nozzle is the possibility of supersonic flight in two different regimes adapted into two different altitudes, under the assumption of a calorically and thermally perfect gas. This type of nozzle has an inflection point at the attachment point of the second bell to the first bell. The design is done using the method of characteristics. Solving the equations is done numerically by the predictor corrector algorithm. The validation of the results is controlled by the convergence of the critical sections ratio, calculated numerically, to that given by the theory. In this case, all the design parameters automatically converge towards the desired solution.
-
천연가스 유량 측정에서 헬름홀츠 자유에너지를 이용한 임계유동함수 계산
하영철(Young-Cheol Ha),허재영(Jae-Young Her) 대한기계학회 2013 大韓機械學會論文集B Vol.37 No.12
본 연구에서는 천연가스 유량 측정에서 2차 표준으로 사용되는 소닉노즐 뱅크 12개 노즐 패키지로 구성 의 임계유동함수 계산 시간을 1초 이하로 단축하고자 하였다. 이를 위해 AGA 8-dc 상태방정식을 적용한 헬름홀츠 자유에너지를 유도하고 이로부터 적분 항이 없는 열역학 상태량 식을 도출하여 CFF 계산에 적용하였다. 그 결과 CFF 계산 시간이 기존 6.7초/12개에서 0.6초/12개로 크게 감소하는 것을 확인할 수 있었고 이 계산 시간은 가스 성분 수와 거의 무관함도 알 수 있었다. 또한 본 계산 결과의 정확도를 확인하기 위해 기존 CFF 국제비교연구의 결과와 비교한 결과 차이가 없음도 확인하였다. This study aimed to calculate the CFFs (critical flow functions) of a sonic nozzle bank with a 12-nozzle package within 1 s. Toward this end, the Helmholtz free energy of natural gas was formulated by using the AGA8-dc equation of state in a form without integral terms, and thereafter, thermodynamic properties such as the enthalpy, entropy, speed of sound, and heat capacity, which are used in CFF calculation, were derived in analytical form. As a result, the calculation time of CFFs was improved from 6.7 s in a previous study to 0.6 s per 12-nozzle package and kept almost constant regardless of the number of components in natural gas. Furthermore, it was confirmed that the calculated CFF values were in agreement with the results of a CFF international comparison test carried out under ISO management in 1998?1999.
-
임재명(J.M. Lim),박경암(K.A. Park),윤복현(B.H. Yoon),최해만(H.M. Choi) 한국유체기계학회 2007 유체기계 연구개발 발표회 논문집 Vol.- No.-
The aim of this paper is to develop the technology of minute gas flow-rate, which is very important in the fields of semiconductor process and NT(Nano Technology). To reach the aim mentioned above we developed the following measurement method. Firstly, we manufactured several some nozzles of the same throat diameters with the same configuration, and calibrated them by means of the standard measurement system. Then we selected a group of sonic nozzles with the similar characteristics. Lastly, we instituted some nozzles from one nozzle in the upstream and other some nozzles from two nozzles in the downstream. In this way we could all the flow-rates(discharge coefficient) for the some nozzles of the same nominal throat diameter.
-
-
Tatsuya Funaki,Tomonori Kato,Kenji Kawashima,Toshiharu Kagawa 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8
In industry, an unsteady flow rate measurement of gases is becoming important increasingly. Our group has been developed an unsteady flow generator with an isothermal chamber for gases and showed that the calibration of the dynamic characteritics for the tested flow meter was effective. However, not only the measurement of the instantaneous flow rate value but also the evaluation of the time mean value in the unsteady flow becomes important in inustry. And it was difficult to control precisely the time mean value of the generated flow rate using the former unsteady flow generator which we developed. To solve this problem,our group developed an oscillatory gas flow generator with highly preciseinlet flow control system in 2008. In this research, to improve and clarify the precision of the generated flow rate with the oscillatory gas flow generator, we conduct to evaluate the performance of the in let flow rate control system with the sonic nozzle and the high precise pressure regulator. As a result, the highre producible results and stability were shown. Moreover, we perform the experiments and uncertainty analysis and confirm the effective of the suggested method.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
