2스풀 분리 배기 방식 엔진의 정상상태 성능모사 및 작동 진단

추교승,성홍계 항공우주시스템공학회 2019 항공우주시스템공학회지 Vol.13 No.1

There is a growing interest in engine diagnostic technology for gas turbine engines. An engine simulation program, precisely simulating the engine performance, is required in order to apply it to the engine diagnosis technology for engine health monitoring. In particular, the simulation program can predict not only design point performance but also off-design point and partial load performance in accurate. So the engine simulation program for the 2-spool separate flow type turbofan engine was developed and the JT9D-7R4G engine of PW(Pratt & Whitney) was analyzed. The steady-sate performance analysis is conducted at both design and off-design points in flight path and the differences between analysis results of takeoff and cruise conditions are compared. The effect of Reynold’s correction method was analyzed as a scaling method of the engine component performance. The simulation results was compared with NPSS 가스터빈 엔진에 대한 엔진 진단기술에 대한 관심이 높아지고 있으며, 엔진 건전성 진단기술에 적용 가능한 정확한 엔진 성능모사 프로그램의 중요성은 점점 더 커지고 있다. 이를 위한 엔진 성능모사는 설계점 해석으로부터 시작하여 탈설계점 성능모사, 부분부하 성능모사를 정확하게 수행해야 할 필요가 있다. 이에 따라 본 연구에서는 2-스풀 분리 배기 방식 터보팬 엔진에 대한 엔진 시뮬레이션 프로그램을 개발하고 PW(Pratt & Whitney)사의 JT9D-7R4G 엔진을 해석하였다. 각 비행영역에서의 설계점과 탈설계점에서의 정상상태 성능모사를 수행하고, 최대이륙조건 설계점과 순항상태 설계점의 해석결과의 차이를 비교하였다. 또한 구성품 성능선도 축척법 중 하나인 Reynold’s Correction의 효과를 분석하였다. 개발된 프로그램의 결과와 NPSS의 결과를 비교하여 프로그램을 검증하였다.

스털링 기관의 열효율에 대한 설명방식 및 대학생들의 사고과정 분석

이주현,송진웅 한국물리학회 2009 새물리 Vol.59 No.3

The purpose of this study was to find out the explanations for how to solve the contradiction among the three statements suggesting 1) all reversible heat engines operating between two reservoirs have the same efficiency; 2) ideal Stirling engine operates reversibly; and 3) the efficiency of Stirling engine is lower than the efficiency of Carnot engine, as well as to analyze undergraduate students’ thoughts about this contradiction. The participants were 24 students who were taking a university course on thermal and statistical physics. Our analysis about the explanations of Stirling engine efficiency showed that Stirling engine which had no regenerator could not operate reversibly between two reservoirs and the heat efficiency of the Stirling engine was lower than that of Carnot engine. However, Stirling engine having a regenerator could operate reversibly and the efficiency was the same as Carnot engine. The analysis of students’ responses showed that most students considered the entropy of Stirling engine as the most important factor in determining whether the Stirling engine operates reversibly or not. However, they did not understand well the relation between entropy and the reversible process. Many of them also offered answers about the solution of the contradiction as either ‘Stirling engine cannot operate reversibly,’ or ‘I simply don’t know.’ If this contradiction is closely discussed with deep consideration of the reversible process, students’ understanding of the thermodynamic concepts might be improved. 본 연구의 목적은 ‘두 열원 사이에서 가역적으로 작동하는 열기관의 효율은 모두 동일하다.’는 서술과 ‘이상적인 스털링 기관은 가역적으로 작동한다.’는 서술, 그리고 ‘이상적인 스털링 기관의 효율은 카르노 기관보다 낮다.’는 세 서술 사이의 모순 관계를 해결할 수 있는 스털링 기관의 열효율에 대한 설명 방식을 조사하고, 이 문제에 대한 대학생들의 사고 과정을 살펴보는 데 있다. 연구 참여자는 열 및 통계물리 과목을 수강하는 24명의 물리교육 전공 학생들이다. 스털링 기관의 열효율에 대한 설명 분석에 따르면, 스털링 기관은 재생기의 도움 없이는 두 열원 사이에서 가역적으로 작동할 수 없으며, 재생기가 없는 경우에 스털링 기관의 열효율은 카르노 기관보다 낮다. 하지만 재생기를 도입하면 스털링 기관과 카르노 기관의 효율이 동일함을 증명할 수 있다. 학생들은 스털링 기관이 가역적으로 작동하는지의 여부를 결정하기 위해 시스템의 엔트로피에 대해 주로 논의하였으나, 엔트로피와 가역과정 사이의 관계에 대해서 잘 알지 못하였다. 모순 상황에 대해서도 단순히 스털링 기관은 비가역적으로 작동한다고 답하거나 잘 모른다고 응답한 경우가 많았다. 가역과정에 대한 적절한 설명과 함께 이 문제를 해결한다면, 학생들의 열역학 관련 개념들에 대한 이해도가 높아질 것으로 기대된다.

MORPHOLOGY AND OXIDATION KINETICS OF CI ENGINE’S BIODIESEL PARTICULATE MATTERS ON CORDIERITE DIESEL PARTICULATE FILTERS USING TGA

P. KARIN,J. BOONSAKDA,K. SIRICHOLATHUM,E. SAENKHUMVONG,C. CHAROENPHONPHANICH,K. HANAMURA 한국자동차공학회 2017 International journal of automotive technology Vol.18 No.1

The impact of small compression ignition (CI) engine operation conditions and fuel properties on diesel and biodiesel particulate matters (PMs) quantity using opacity smoke meter is investigated. The biodiesel engine’s PMs are around a half of diesel engine PMs under the same engine operation conditions. Morphology of both engine’s PMs are also studied using a Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and image processing method. The average primary nanoparticle sizes of diesel and biodiesel engine’s PMs are approximately 34 nm and 32 nm, respectively. The result shows that engine operation condition and fuel property are strongly impact on the quantity and size distribution of primary nanoparticles emission. PM oxidation kinetics on conventional cordierite Diesel Particulate Filters (DPFs) powders by Thermo-gravimetric analysis (TGA) is also successfully studied. The calculated apparent activation energies of biodiesel engine’s PM oxidation on conventional cordierite DPFs powders are lower than that of diesel engine’s PM and carbon black because of unburned oxygenated molecule. The calculated apparent activation energy of biodiesel engine’s PM and diesel engine’s PM oxidize on conventional cordierite DPFs powders with pure air are in the range of 109 ~ 131 kJ/mole and 117 ~ 130 kJ/mole, respectively. It might be expected that smaller primary nanoparticle size of biodiesel engine’s PMs and biooxygenate unburned hydrocarbon can promote more PM oxidation rate during vehicle’s DPF regeneration process.

터보팬 엔진 시험 설비 구축에 관한 연구

곽도협(Dohyup Kwak),김병현(Byunghyun Kim),김보경(Bogyoung Kim),박건국(Konkok Park),최희주(Heeju Choi) 한국추진공학회 2016 한국추진공학회 학술대회논문집 Vol.2016 No.12

개발된 전자식 엔진 제어 장치(EECU, Electrical Engine Control Unit)의 최종 성능 검증을 위하여 터보팬 엔진의 운용 시험을 수행하였다. 본 논문은 터보팬 엔진을 운용하기 위한 엔진 시험설비에 대하여 서술하였다. 엔진 시험 설비는 터보팬 엔진 장착 및 고정을 위한 설비부, 연료 공급을 위한 연료공급부, 엔진의 상태 확인 및 데이터 저장이 가능한 DAS(Data Acquisition System)부, 엔진 제어장치에 명령 인가를 위한 제어 콘솔부, 과온 과속으로부터 엔진을 보호하는 엔진 보호부로 구성하였다. For the final verification of developed EECU, the engine operating test is conducted using Turbo fan engine. This paper describe the engine test facility for operating turbofan engine. The engine test facility is composed of an engine installation part for the installation and fixing of engine, a fuel supply part, DAS(Data Acquisition System) part for the engine state monitoring and data saving, an engine control console part for the approval commands to EECU, an engine protection part for the protecting engine from over-speed, over-temperature.

국내외 게임 엔진 사용성 평가를 통한 스마트폰 게임 개발에 관한 연구

박선하(Park, Sunha) 한국디지털디자인협의회 2015 디지털디자인학연구 Vol.15 No.1

스마트폰 게임의 성장은 게임 플랫폼의 다양한 개발과 더불어 온라인 게임에 비해 상대적으로 저렴하고 쉽게 개발할 수 있는 모바일 게임 산업의 성장세에 큰 영향을 주었다. 그리고 더 나아가 게임 엔진의 다양화와 발달까지 연결고리를 만들었다. 게임 개발을 도와주는 것이 바로 ‘게임엔진’이다. 엔진을 사용하여 게임을 쉽게 개발하고 퍼블리싱할 수 있기 때문에 다양한 스마트폰 게임이 시도되고 있는 것이며, 이러한 요소들이 바로 현 게임시장에서 확연히 보여지는 현상이다. 오늘날 상용화된 다양한 엔진의 퍼블리싱 사례 및 특징들을 바탕으로 엔진 활용성 측면을 분석해보고, 그 중 게임 교육과정에 적절한 대표적인 게임 엔진으로 게임샐러드를 선정하여 게임 개발에 활용 할 수 있는 방법을 제시하고자 하였다. 게임개발 교과목에서 개발언어의 기초학문에 대한 경험이 전혀 없는 학생들을 대상으로 엔진을 활용한 수업을 진행하여 게임 제작을 완성하였다. 그리고 제작된 게임을 가지고 엔진에 대한 사용 방법, 엔진의 특성과 및 향후 사용 가능성을 제시하였다. 본 연구는 현 시대의 게임관련 교육시스템에 활용 할 수 있는 참고 자료로서 역할이 가능하며, 향후 연구할 과제로서 적절하다 고려된다. A Growth of a game for a smartphone have a significant impact on the growth of the mobile gaming industry which is relatively inexpensive and easy to develop a game compared to online games, with the development of a variety of gaming platforms. And it also give a connection diversification and development of a game engine. It is a game engine which help the game development. Because you can use the engine to develop and publish games easily, a variery of games for the smartphone is developed and it is seen cleary in the gaming market that the use of game engine is a phenomenon. Analyzing the utilization of a engine based on various case of a commercial publishing and characteristics of a engine recently, I tried to give a solution for appling a game development to use a Game salad which is suitable curriculum for game education among leading game engine. With students who have no experiences of a basic development language in the curriculum, A game is produced by proceeding a class which using a engine. I suggest that use, characteristics, and potential of a engine with a game which made by a engine. Engine plays a role as a reference that may be utilized for game-related educational system and it is considered well over a subject to study in the future.

SpaceX의 엔진개발 전략 분석

이금오(Keum-Oh Lee),김대진(Dae-Jin Kim),박순영(Soon-Young Park),이기주(Keeju Lee) 한국추진공학회 2018 한국추진공학회 학술대회논문집 Vol.2018 No.12

SpaceX는 저가형 Merlin 엔진 개발 및 Falcon 9의 성공적인 발사 및 회수를 통하여 뉴스페이스 시대를 이끌어 가고 있다. SpaceX는 초기에 케로신 가스발생기 엔진인 Merlin 엔진을 개발하여 지속적인 개량을 통해서 경쟁력을 높였으며, 차세대 엔진으로 메탄 다단 연소 사이클 엔진인 Raptor 엔진을 개발하였다. 탑재체 중량을 결정한 후 엔진을 개발하지 않고, 가용한 엔진을 개발한 후 탑재체 중량을 계속 늘려나갔다. SpaceX is leading the era of New Space through the development of low-cost Merlin engine and successful launch and recovery of Falcon 9. SpaceX developed the Merlin engine, a kerosene gas generator engine, improved its competitiveness through continuous improvement, and developed the Raptor engine, a methane staged combustion cycle engine, as the next generation engine. It did not develop the engine after deciding the weight of the payload but continued to increase the weight of payload after developing a usable engine.

신개념 로터리 엔진의 개발 (Ⅰ) : 개념과 이론적 성능 분석 Concept and theoretical performance analysis

오문근,이규승,박원엽 한국농업기계학회 2003 바이오시스템공학 Vol.28 No.1

Present combustion engines have reached almost at the limit of development due to the fundamental structural problems. This study was carried out to propose a new concept internal combustion engine which has great potential advantages to the conventional engines. Proposed new concept engine is a kind of rotary engine. A rotor is rotating concentrically in a cylinder which is divided into two partitioning valves, and it makes four compartments in the cylinder. The volumes of each of four compartments are changing continuously with the rotor movement, and performs the functions of intake, compression, expansion and exhaust simultaneously. the results of this study can be summarized as follows: 1. Expected theoretical thermal efficiency is 44.9 percent at the condition of 1000rpm and compression ratio of 8.0, which is almost the same as that of the conventional engines, i.e., piston and Wankel rotary engine. 2. The new concept engine has 2 working strokes in every revolution. Therefore, the new concept engine can reduce the specific weight and volume than four-stroke pistion engine. 3. The torque variation is very small. therefore minimal noise and vibration are expectable. 4. The new concept engine can reduce mechanical energy loss than pistion engine because neither crank mechanism nor eccentrical motion exists.

A study of operating parameters on the linear spark ignition engine

Lim, O.,Hung, N.B.,Oh, S.,Kim, G.,Song, H.,Iida, N. Applied Science Publishers 2015 APPLIED ENERGY Vol.160 No.-

In this paper, we present our experiment and simulation study of a free piston linear engine based on operating conditions and structure of the linear engine for generating electric power. The free piston linear engine includes a two-stroke free piston engine, linear generators, and compressors. In the experimental study, the effects of key parameters such as input caloric value, equivalence ratio, spark timing delay, electrical resistance, and air gap length on the piston dynamics and electric power output are investigated. Propane is used as a fuel in the free piston linear engine, and it is premixed with the air to make a homogeneous charge before go into the cylinder. The air and fuel mass flow rate are varied by a mass flow controller. The experimental results show that the maximum generating power is found with the value of 111W at the input caloric value of 5.88kJ/s, spark timing delay of 1.5ms, equivalence ratio of 1.0, electric resistance of 30Ω, and air gap length of 1.0mm. In order to check the durability of the linear engine, a durable test is conducted during 100h. The experimental results show that there are no problems for the linear engine after about one hundred hours of the durable test. Beside experimental study, a simulation study is conducted to predict operating behavior of the linear engine. In the simulation study, the two-stroke free piston linear engine is modeled and simulated through a combination of three mathematical models including a dynamic model, a linear alternator model and a thermodynamic model. These mathematical models are combined and solved by a program written in Fortran. Besides, the effects of key parameters such as reciprocating mass, spark timing and spring stiffness on the piston dynamics and electric power output of the linear engine are also investigated. The simulation results show that the simulation and experimental data are nearly similar at the same initial conditions. In addition, a highest generating power of the linear engine can be easily found by optimizing the key parameters.

CNG/Diesel 이종연료용 엔진의 성능 및 배출가스 특성에 대한 연구

임옥택(Ock Taeck Lim) 대한기계학회 2011 大韓機械學會論文集B Vol.35 No.9

CNG/diesel dual-fuel 엔진은 CNG 를 주 연료로 사용하고 소량의 디젤을 착화제로서 실린더 내에 분사한다. 본 연구에서는 기존의 디젤엔진을 커먼레일직접분사(CRDI)를 통하여 고압으로 디젤을 분사하고, 예혼합을 위하여 CNG 를 흡기포트에 분사하는 CNG/diesel dual-fuel 엔진으로 개조하였다. CNG/diesel dualfuel engine 은 기존의 디젤엔진과 동등한 수준의 토크 및 출력성능을 나타내었다. 또한, CNG 대체율은 CNG/diesel dual-fuel 엔진의 전체 운전영역에 대하여 89% 이상을 만족시켰다. Dual-fuel 엔진의 PM 배출농도는 디젤엔진보다 94% 더 낮게 나타났지만, NOx 배출농도는 더 높게 나타났다. In a CNG/diesel dual-fuel engine, CNG is used as the main fuel and a small amount of diesel is injected into the cylinder to provide ignition priming. In this study, a remodeling of the existing diesel engine into a CNG/diesel dual-fuel engine is proposed. In this engine, diesel is injected at a high pressure by common rail direct injection (CRDI) and CNG is injected at the intake port for premixing. The CNG/diesel dual-fuel engine had an equally satisfactory coordinate torque and power as the conventional diesel engine. Moreover, the CNG alternation rate is over 89% throughout the operating range of the CNG/diesel dual-fuel engine. PM emission by the dual-fuel engine is 94% lower than that by the diesel engine; however, NOx emission by the dual-fuel engine is higher than that by the diesel engine.

Analysis of Game Engine Architecture Framework

이동훈,배재환 (사)한국컴퓨터게임학회 2015 한국컴퓨터게임학회논문지 Vol.28 No.3

Physics game engine, the graphics engine and network engine, artificial intelligence engine, sound engine, isometric engine that is more variety such thoughts. The engine for the convenience of the various parts during manufacture of the game. If there is no engine, it is to use this to be produced by programming a portion corresponding thereto directly, saving time and money. For example, look at some first example I saw a lot of Havok physics engine in the engine is relatively inde For example, depending on the intensity and direction of the character is pushed when the hammer hits the hammer Distance, angle, an engine that can help you easily apply a variety of calculations, such as physical strength. The following is a typical wah, etc. also wrote the Gamebryo graphics engine as. Sikimyeo optimize the graphics engine built object in 2D or 3D image through techniques such as Shader serves to make faster, more glamorous images that appear on the screen. Artificial intelligence engine to assist so that you can easily AI characters Any engine helps but, for example, A * pathfinding algorithm, easy to like Adjust the AI ​​monster any play a role. Thus the role that can help you more easily and quickly to play the game engine is produced. In the paper, we analyze the "Unreal Engine" and "Unity3D" engine.