• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.30 no.1
• /
• pp.105-113
• /
• 2002

In this study, the steady state performance analysis program was developed for a turboprop engine, and its performance was analyzed at uninstalled and installed conditions. For the purpose of evaluation the developed program was compared with the performance data provided by the engine manufacturer and analysis results of GASTURB8.0 program. It was confirmed that the developed program was reliable because the results by the developed program were well agreed with those by GASTURB8.0 within %%. The linear and non-linear GPA(Gas Path Analysis) programs for performance diagnotics were developed, and selection of optimal measurement variables was studied. Furthermore, in order to investigate effects of the number and the kind of measurement variables, the linear and non-linear GPAs were analyzed with various measurement set. If the measurement parameters were properly selected, the reliable and economic faults detection might be possible even thought the small number of measuring parameters were used.

• Korean Journal of Computational Design and Engineering
• /
• v.18 no.4
• /
• pp.250-257
• /
• 2013

This paper introduces a failure analysis procedure that underpins real-time fault prognosis. In the previous study, we developed a systematic eventization procedure which makes it possible to reduce the original data size into a manageable one in the form of event logs and eventually to extract failure patterns efficiently from the reduced data. Failure patterns are then extracted in the form of event sequences by sequence-mining algorithms, (e.g. FP-Tree algorithm). Extracted patterns are stored in a failure pattern library, and eventually, we use the stored failure pattern information to predict potential failures. The two practical case studies (marine diesel engine and SIRIUS-II car engine) provide empirical support for the performance of the proposed failure analysis procedure. This procedure can be easily extended for wide application fields of failure analysis such as vehicle and machine diagnostics. Furthermore, it can be applied to human health monitoring & prognosis, so that human body signals could be efficiently analyzed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2008.03a
• /
• pp.437-441
• /
• 2008

A non-toxic Post Boost Stage(PBS) with LOX/Ethanol engine was successfully demonstrated at the Tomioka Facility of IHI Aerospace. IHI Aerospace has researched and developed the nontoxic propulsion systems and the LOX/Ethanol is one of the most attractive non-toxic bipropellant candidates. ${\rho}ISP$ of LOX/Ethanol is higher than ${\rho}ISP$ of the other non-toxic bipropellants as LOX/HC or $LOX/LH_2$. The authors studied the combustion characteristics of LOX/Ethanol propellant with the engine designed for LOX/LNG propellant. Also the injector with a built-in igniter was designed and examined its feasibility, ignition and combustion characteristics. We have demonstrated Post Boost Stage with future LOX/Ethanol engines. This propulsion system is targeted for expandable vehicle upper stage to accelerate delta-V to reach the required orbit. PBS Demonstration Model is designed as a test stand to evaluate feed system for integrated propulsion system and also to demonstrate Integrated Vehicle Health Management(IVHM) technique using local valve control and also valve behavior-monitoring capability.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.27 no.4
• /
• pp.361-370
• /
• 2017

Objectives: This study evaluated the diesel engine exhaust (DEE) exposure levels of door-to-door deliverers in Daegu from July to September. Methods: We measured exposure levels of DEE surrogates for the same door-to-door deliverers who joined the particulate matter 2.5 exposure study previously published in this journal. Black carbon(BC) concentrations were measured using real-time BC monitoring devices with 1 minute interval. $NO_2$ concentrations were monitored using passive badges. DEE exposure data were analyzed using the same characteristics and GPS information as the first study. Results: A total of 40 measurements of BC concentrations and $NO_2$ concentrations were collected during delivery of parcels. The average exposure levels to BC, and $NO_2$ were $2.23{\mu}g/m^3$ ($0.001-350.85{\mu}g/m^3$) and 21.26 ppb(3.3-61.37 ppb), respectively. Exposure levels to BC according to the day of a week and coverage areas were not significantly different(p>0.05). Delivery trucks manufactured before 2006 caused significantly higher exposure to BC than the trucks manufactured after 2006(p<0.05). Exposure levels of BC integrated for each time in residential area and roadsides were $1.96{\mu}g/m^3$ and $3.46{\mu}g/m^3$, respectively, and the difference was statistically significant(p<0.001). The Pearson correlation coefficients between the ambient $PM_{2.5}$ and BC was significant, r=0.26(p<0.01); however, the correlations between $PM_{2.5}$ and ambient $PM_{2.5}$, and between BC of DEE and $PM_{2.5}$ of DEE did not show a significant correlation Conclusions: BC and $NO_2$ exposure levels were significantly lower when door-to-door deliverers drove newer trucks. BC exposure levels of deliverers were higher in roadsides than in residential area. DEE from nearby vehicles through open windows might be the main source of BC exposure.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.3 no.1
• /
• pp.24-33
• /
• 1999

For performance prediction and diagnostics of gas turbine engines, linear and non-linear gas path analysis are applied. In order to find optimal instrument parameters to detect the physical faults such as (outing, erosion and corrosion, non-linear gas path analysis is used. A typical industrial gas turbine engine, TB5000, is used to study the effect of physical faults on engine performance. Through comparison of RMS error between linear and non-linear gas path analysis, the optimal instrument parameters can be defined. As a result, it is found that the linear GPA has the level of error introduced by the assumption of the linear mode: can be of the same order of magnitude as the fault being soughtwhile the non-linear GPA can be solved the non-linear relationships between dependent and independent parameters using an iterative method such as the Newton-Raphson method with sufficient accuracy.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.4 no.4
• /
• pp.87-97
• /
• 2000

A steady state performance simulation and diagnostics program for the turboprop engine (PT6A-62), which is the power plant of the first developed military basic trainer KT-1 in Republic of Korea, was developed. The developed steady state performance analysis program was evaluated with the performance data provided by the engine manufacturer and with analysis results of GASTURB program, which is well known for the performance simulation of gas turbines. Performance parameters were discussed to evaluate validity of the developed program at various cases such as altitude, flight velocity and part load variation. GPA(Gas Pass Analysis) allows engine performance deterioration to be identified at the module level in terms of reduction in component efficiencies and changes in mass flow. In order to find optimal instrument set to detect the physical faults such as fouling, erosion and corrosion, a gas path analysis approach is utilized. This study was performed in two cases for selection of optimal measurement parameters. One case was considered with the effect of instrument number by changing independent parameter number. The other case was performed with selection of independent parameter set. According to the analysis results, the optimal measurement parameters selected were eight dependent variables such as shaft horsepower, fuel flow rate, compressor exit pressure and temperature, compressor turbine inlet pressure and temperature and power turbine inlet pressure and temperature.

• Journal of the Korea Convergence Society
• /
• v.8 no.3
• /
• pp.15-22
• /
• 2017

People generally believe that disaster forecast and warning systems and response systems are well established in the age of cutting edge technology. As a matter of fact, reliable systems to respond to disasters are not properly equipped, as we witnessed the Sewol ferry disaster in 2014. The existing forecast and warning systems are based on sensor information with low efficiency, and image information is only operated by monitoring staff manually. In addition, the interconnection between a warning system and a response system in order to decide how to cope with the recognized disaster is very insufficient. This paper introduces the CCTV based disaster recognition and real time crisis response system composed of the CCTV image recognition engine and the crisis response technique. This system has brought the possibility to overcome the limitations of existing sensor based forecast and warning systems, and to resolve the problems in the absence of monitoring staff when responding to crisis.

• Journal of Advanced Marine Engineering and Technology
• /
• v.40 no.1
• /
• pp.28-33
• /
• 2016

Batteries are used for main power engine in the fields such as mobiles, electric vehicles and unmanned submarines, for starter and lamp driver in general automotive, for emergency electric source in ship. These days, lead-acid and the lithium ion batteries are increasingly used in the fields of the secondary battery, and the lead-acid battery has a low price and safety comparatively, The lithium ion battery has a high energy density, excellent output characteristics and long life, whereas it has the risk of explosion by reacting with moisture in the air. But Recently, due to the development of waterproof, fireproof, dustproof technology, lithium batteries are widely used, particularly, because their usages are getting wider enough to be used as a power source for hybrid ship and electric propulsion ship, it is necessary to manage more strictly. Hybrid ship has power supply units connected to the packets to produce more than 500kWh large power source, and therefore, A number of the communication modules and wires need to implement the wire inspection and monitor system(WIIMS) that allows monitoring server to transmit detecting voltage, current and temperature data, which is required for the management of the batteries. This paper implements a low price type wireless inspection and monitoring system(WILIMS) of the lithium ion battery for hybrid vessels using BLE wireless communication modules and power line modem( PLM), which have the advantages of low price, no electric lines compared to serial communication inspection systems(SCIS). There are state of charge(SOC), state of health(SOH) in inspection parts of batteries, and proposed system will be able to prevent safety accidents because it allows us to predict life time and make a preventive maintenance by checking them at regular intervals.