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
- 저자 : Jacobs Somnic (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
Comparison of RDE Simulation Methods
Jacobs Somnic,Foluso Ladeinde 한국추진공학회 2018 한국추진공학회 학술대회논문집 Vol.2018 No.12
Air-breathing Rotating Detonation Engine (RDE) has been widely investigated using a variety of techniques for the kinetic mechanism, turbulence, turbulence-combustion interaction, the spatial and temporal numerical procedure, and the use of Euler or the Navier-Stokes equations. However, there seems to be no consensus presently as to the optimal combination of procedures to use. In this work, a comparison of various modeling options is presented for the physics, chemistry, and numerical modeling of the RDE problem. Differing performance of several kinetic mechanisms has been observed and the two spatial numerical schemes investigated – the Weighted Essentially-Non-oscillatory (WENO) and MUSCL – give significantly different results. In this limited study, Euler and Navier-Stokes give results that are not significantly different, although the real issue in this case is the level of numerical dissipation, since no truly inviscid solutions to the flow equations are physically or numerically realizable. Other effects will be reported during the oral presentation.
-
Numerical Study on the Effect of Equivalence Ratio on Rotating Detonation Engine Flow field
Jacobs Somnic,Foluso Ladeinde 한국추진공학회 2019 한국추진공학회 학술대회논문집 Vol.2019 No.5
Rotating detonation engines (RDEs) have been extensively investigated recently as a candidate for an air-breathing propulsive system with high thermal efficiency, with most of the studies focusing on premixed combustion under stoichiometric conditions. Because a purely stoichiometric condition cannot be ascertained in realistic applications, the knowledge of the effects of equivalence ratio becomes very important. The present study has the objective of investigating the effects of equivalence ratio on premixed combustion in a realistic RDE system. For this purpose, both one-dimensional and two-dimensional spatial models are studied. The effects on the pressure, temperature, and chemical species distributions will be presented. A basic RDE is shown in Fig. 1. The combustion chamber is an annular ring, where the direction of flow is from the head end (bottom in figure) to the exit plane (top of figure). In experimental study, the fuel and oxidizer are injected separately into the combustion chamber to avoid backfire [2]. The mixing process occurs inside the combustion chamber while detonation wave propagates circumferentially to consume fresh reactive mixture. Schwer et al. [2] investigated the flow field of RDE in general and observed the effect of stagnation and back pressure on an RDE. In addition, Schwer et al.[3] also examined the fluid dynamics of rotating detonation engines with hydrogen and hydrocarbon fuels. Jin Zhou et al.[4] studied the effects of injection nozzle exit width on rotating detonation engine. These studies pertain to stoichiometric conditions. Only a handful of studies have investigated the effects of equivalent ratio. Wang et al.[5] recently investigated the effects of equivalence ratio and found that as the equivalence ratio increases, the velocity of the rotating detonation wave first increases and then decreases. Baoxing et al [6] experimentally studied the effects of equivalence ratio on RDE and found that for their engine model operating with equivalence ratio from 0.42 to 1.43, the rotating detonation wave was successfully initiated, and propagation self-sustained. In this study, we are interested to see how equivalence ratio influence RDE flow field in general. Furthermore, we want to see how it affects the detonation wave structure Key Words: Rotating Detonation Engine, Computational Fluid Dynamics (CFD), Supersonic Combustion, Equivalence Ratio.
-
고장물리에 기반한 고온용 온도센서 솔더접합부의 수명향상연구
박승일(SeungIl Park),제이콥스 솜닉(Jacobs Somnic),한창운(Changwoon Han),이현석(Hyeonseok Lee),안영기(YoungGi An),정재성(Jae Seong Jeong),류해용(Haeyoung Ryu),사윤기(Yoonki Sa) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12
Photo lithography is an important step in semiconductor process. This process affects the quality of the semiconductor. In recent report, the failures of solder joint is observed in a short span of time at the equipment carrying out the photo lithography process. One of the failures is fracture due to the condition of solder joints in high temperatures (~230°C). Result of analysis based on Physics-of-Failure confirmed that at high temperatures, excessive stress is generated in the solder joint due to viscoplasticity. For this situation, the failure mechanism of solder joints is assumed to be creep. In this paper, we suggest which solder better for the temperature sensor solder joint at high temperature based on Physics-of-Failure. In addition, we perform the life prediction for 97.5Pb2.5Sn solder. As a result, sintered nano-scale silver paste has longer lifetime than 97.5Pb2.5Sn due to lower stress values at high temperature conditions.
-
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
