• 대한기계학회논문집B
• /
• 제26권8호
• /
• pp.1132-1137
• /
• 2002

In this paper, the test results of the combustion for 2 IAFR lean fuel models are described. The need for the low emission combustor has been issued from the concern on the increase of green house and the destruction of ozone layer. To evaluate the flow and combustion performance of newly designed 21AFR lean modules, the hydraulic tests in stereolithographic airflows models, the low pressure combustion tests in three injectors model for weak extinction and ignition and the high pressure combustion tests in single sector for NOx, SAE and efficiency are performed. The low pressure tests reveal that the governing parameters in weak extinction and ignition at atmospheric condition are prefilmer length, swirl flow rotation direction, secondary swirl angle and flow split. As a result of combustion test at high pressure, the efficiency and smoke level are satisfied with performance targets, but EINOx of 17.8 is higher than target value of 13.1 The high pressure tests show that the main parameters influenced on NOx are primary swirl angle, swirl flow rotation direction, heatshield exit angle and liner mixing hole location.

• 한국지진공학회논문집
• /
• 제13권4호
• /
• pp.25-35
• /
• 2009

기존의 교량받침으로 많이 사용되고 있는 폴리우레탄 디스크를 적용한 POT형식에 C형 강재감쇠장치를 추가적으로 적용한 새로운 형태의 지진격리장치에 대한 명확한 정적 성능검증과 동적특성을 파악하기 위하여 최대 극한 수직하중 시험, 최대 회전 시험, 동적재하 시험 및 동적재하 극한 반복시험을 시행하였다. 해석적 결과와 성능시험 결과를 비교분석한 결과, 충분한 감쇠능력을 보유하고있을 뿐만 아니라, 설계기준에도 적합하다는 결론을 얻을 수 있었다. 또한, EDC 및 유효강성값의 시험치가 이론치와 유사하여 시험 결과값의 분석이 유효함을 보였다.

• 소성∙가공
• /
• 제32권3호
• /
• pp.114-121
• /
• 2023

During rolling, rolling mill rolls endure wear when shaping metal billets into a desired form, such as bars, plates, and shapes. Such wear affects the lifespan of the rolls and product quality. Therefore, in addition to rigidity, wear performance is a key factor influencing the performance of rolling mill rolls. Conventional methods such as casting and forging have been used to manufacture rolling mill rolls. However, powder alloying methods are increasingly being adopted to enhance wear resistance. These powder manufacturing methods include atomization, canning to shape the powder, hot isostatic pressing to combine the powder alloy with conventional metals, and various wear performance tests on rolls prepared with powder alloys. In this study, numerical simulations and experimental tests were used to develop and elucidate the wear analysis mechanism of rolling mill rolls. The wear characteristics of the rolls under various rolling conditions were analyzed. In addition, experimental tests (wear and surface analysis tests) and wear theory (Archard wear model) were used to evaluate wear. These tests were performed on two different materials in various powder states to evaluate the different aspects of wear resistance. In particular, this study identifies the factors influencing the wear behavior of rolling mill rolls and proposes an analytical approach based on the actual production of products. The developed wear analysis mechanism can serve the future development of rolls with high wear resistance using new materials. Moreover, it can be applied in the mechanical and wear performance testing of new products.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
• /
• pp.5-21
• /
• 2006

Traditional standards and specifications for concrete have largely been prescriptive, (or prescription-based), and can sometimes hinder innovation and in particular the use of more environmentally friendly concretes by requiring minimum cement contents and SCM replacement levels. In December 2004, the Canadian CSA A23.1-04 standard was issued which made provisions (a) for high-volume SCM concretes, (b) added new performance requirements for concrete, and (c) clearly outlined the requirements and responsibilities for use in performance-based concrete specifications. Also, in December 2003, the CSA A3000 Hydraulic Cement standard was revised. It (a) reclassified the types of cements based on performance requirements, with both Portland and blended cements meeting the same physical requirements, (b) allows the use of performance testing for assessing sulphate resistance of cementitious materials combinations, (c) includes an Annex D, which allows performance testing of new or non-traditional supplementary cementing materials. From a review of international concrete standards, it was found that one of the main concerns with performance specifications has been the lack of tests, or lack of confidence in existing tests, for judging all relevant performance concerns. Of currently used or available test methods for both fresh, hardened physical, and durability properties, it was found that although there may be no ideal testing solutions, there are a number of practical and useful tests available. Some of these were adopted in CSA A23.1-04, and it is likely that new performance tests will be added in future revisions. Other concerns with performance standards are the different perspectives on the point of testing for performance. Some concrete suppliers may prefer processes for both pre-qualifying the plant, and specific mixtures, followed only with testing only 'end-of-chute' fresh properties on-site. However, owners want to know the in-place performance of the concrete, especially with high-volume SCM concretes where placing and curing are important. Also, the contractor must be aware of, and share the responsibility for handling, constructability, curing, and scheduling issues that influence the in-place concrete properties.

• 항공우주기술
• /
• 제8권1호
• /
• pp.26-31
• /
• 2009

터보펌프 실매질 시험에 사용하기 위해 제작된 3기의 산화제펌프와 1기의 연료펌프에 대한 단품 수류시험을 실시하였다. 수류시험의 시험 영역(유량비, 캐비테이션 수)은 실매질 시험의 작동 영역을 충분히 포함하였으며, 각 펌프는 설계요구조건을 만족하였다. 시험 결과, 제작된 산화제펌프는 내부 형상에 따라 양정이 약 2% 차이가 났으며 효율 및 흡입성능은 거의 차이가 없었다. 연료펌프의 경우 형상이 같았던 이전 모델과 양정과 효율은 비슷하였으나, 흡입성능은 약간 떨어지는 것으로 나타났다.

• 대한원격탐사학회지
• /
• 제36권4호
• /
• pp.645-652
• /
• 2020

GK2A(GEO-KOMPSAT-2A)satellite has been operating excellently since its launch in Dec 2018. The secondary payload called KSEM (Korean Space Environment Monitor) was equipped into the GK2A satellite along with AMI (Advanced Meteorological Imager) sensor. KSEM is the Korea's first operational geostationary space weather sensor and has been developed collaboratively by KHU (Kyung Hee University) and KARI (Korea Aerospace Research Institute). The interface works between KSEM and GK2A were conducted by KARI. Various interface tests, which aim for evaluating effective functionality of KSEM with the spacecraft, were intensively conducted at KARI facilities. Main tests consisted of mechanical and electrical check-up activities between the KSEM and GK2A. Interface tests of KSEM, which involve pre-launch tests such as ETB and GK2A system level tests, were conducted to evaluate functional and performance of KSEM before the launch. The tests carried out during the GK2A LEOP (Launch and Early Orbit Phase) and IOT (In Orbit Test) period (Dec 2018 ~ June 2019) showed excellent in-orbit performance of KSEM data.

• 전기학회논문지
• /
• 제56권10호
• /
• pp.1744-1750
• /
• 2007

This paper addresses grid interconnection tests of a 3kW transformer-less photovoltaic (PV) inverter to verify the effectiveness of the PV inverter and promote its wide use. The 3kW transformer-less PV inverter, which was equipped with intelligent protection and control system, was manufactured. A hardware test bed was constructed for performance tests of the PV inverter. Control performance and grid protection tests were carried out using the test bed. Test results verify the performance of the power control and grid protection functions of the developed transformer-less PV inverter.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2008년도 춘계학술대회논문집
• /
• pp.416-419
• /
• 2008

In order to ensure the safety, the performance evaluation of the safety-related components in a nuclear power plant such as air-operated valves. In this paper, the diagnostic system(MOVIDS $A^+$) for the performance of air-operated valves was developed. For this purpose, the characteristics of their operation and the methods of the diagnostic tests were reviewed. The setup and diagnostic functions of the system were mentioned. Its applicability was validated through the diagnostic tests of air-operated valves in nuclear power plants. This diagnostic system is now applied in nuclear power plants for performance tests.

• 터널과지하공간
• /
• 제6권2호
• /
• pp.175-183
• /
• 1996

Linear cutting tests on granite were conducted to evaluated the cutting performance of abrasive water jet(AWJ) using several types of abrasives. The abrasives used in the tests were grarnet, alumimum oxide, and silicon carbide. And one type of granite which is comercially known as "KeuchangSuk" was used as workpiece throughout the tests. The results from the tests were described in terms of cutting depth and abrasive productivity. Authors tried to confirm the effects of the operational parameters of abrasive mass flow rate, water pressure, and traverse speed of nozzle on cutting depth and presented almost all the data obtained in the tests. Abrasive productivity can be defined as the area of kerf wall cut by unit weight of abrasive and is an important factor to evaluated the cutting ability of abrasive and assess the cost effectiveness of an AWJ system. In the tests the maximum abrasive productivities of garnet, alumina, and silicon carbide were about 0.21, 0.24, and 0.20 $\textrm{cm}^2$ respectively under similar operational conditions.onditions.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2003년도 추계학술대회 논문집(III)
• /
• pp.659-665
• /
• 2003

This paper presents a Train Communication Network simulator (TCNS) that can be used to evaluate the performance of TCN. TCN was accepted as the standard of the protocol for the communication network in trains. We carry out some simulation tests using the TCNS to show practical uses of the simulator. Results of some simulation tests are also reported. This paper presents a Train Communication Network simulator(TCNS) that can be used to evaluate the performance of TCN. TCN was accepted as the standard of the protocol for the communication network in trains. TCN of fieldbus was adopted as international standardization IEC 61375 in 1999. It has been operating on G7 train in korea. This paper developed TCNS(Train Communication Network simulator) as a simulator for performance evaluation. We can verify TCNS for preventing many kinds of occurring problems between the devices in data-communication. This study was developed TCNS as a simulator for the performance evaluation. We analyzed correlation between token, transmission data per paket and transmission speed of bus, through the TCNS, also analyzed result according to error rate of TCN. We carry out some simulation tests using the TCNS to show practical uses of the simulator. Results of some simulation tests are also reported.