• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.6
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• pp.1621-1632
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• 1993

A numerical simulation is carried out on flows in a rotating serpentine flow passage, which models a cooling passage in a gas turbine blade, by using a 3-D FVM based TURBO-D program. When it is rotating, the flow field exhibits quite different aspects due to the effect of the Coriolis force. Especially the secondary flow field appearing in the cross-sectional area is very complex because of the combined effect of the Coriolis force and the centrifugal force in the curved area. Local Nusselt numbers are also obtained based on the Reynolds analogy and compared with the published experimental data showing a good agreement. The results of the present study can be applied to the design of cooling passages of a gas turbine blade.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.4
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• pp.26-37
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• 2007

A virtual engine test based on "Numerical test cell" can extremely reduce the time and cost for the development of a hardware by coupling multidisciplinary analysis. This paper introduces the development activities of full engine simulation programs in U.S.A. and Europe, with the their related techniques(the engineering models, the simulation environment and high performance computing) based on the NPSS(Numerical Propulsion System Simulation). NASA Glenn research conte. leads the development efforts of NPSS by assembling the current codes and improving their Auctions. VIVACE(Value Improvement through a Virtual Aeronautical Collaborative Enterprise), a consortium of universities, research centers and companies in Europe, is developing the PROOSIS(PRopulsion Object Oriented Simulation Software). The capability for the domestic development is also estimated by surveying the current status.

• Journal of Aerospace System Engineering
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• v.13 no.1
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• pp.38-46
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• 2019

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.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.848-853
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• 2004

Regarding to the project SUAV (Smart Unmanned Aerial Vehicle) in KARI (Korea Aerospace Research Institute), several engine configurations has been evaluated. However it's not an easy task to collect all the necessary data of each engine for the analysis. Usually, some kind of modeling technique is required in order to determine the unknown data. In the present paper a qualitative method for reverse engineering is proposed, in order to identify some design patterns and relationships between parameters. The method can be used to estimate several parameters that usually are not provided by the manufacturer. The method consists of modeling an existing engine and through a simulation, compare its transient behavior with its operating envelope. In the simulation several parameters such as thermodynamics, performance, safety and mechanics concerning to the definition of operation-envelope, have been discussed qualitatively. With the model, all engine parameters can be estimated with acceptable accuracy, making possible the study of dependencies among different parameters such as power-turbine total inertia, TIT, take-off time and part load, in order to check if the engine transient performance is within the design criteria. For more realistic approach and more detailed design requirements, it will be necessary to enhance the compressor map first, and more realistic estimated values must be taken into account for intake-loss, bleed-air and auxiliary power extraction. The relative importance of these “unknown” parameters must be evaluated using sensitivity analysis in the future evaluation. Moreover, fluid dynamics, thermal analysis and stress analysis necessary for the resulting life assessment of en engine, will not be addressed here but in a future paper. With the methodology presented in the paper was possible to infer the relationships between operation-envelope and engine parameters.

• Journal of the Korean Society of Propulsion Engineers
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• v.27 no.1
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• pp.37-48
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• 2023

In this study, performance analysis modeling of two spool mixed flow type turbofan engine according to steady-state and transient is performed. The target engine is selected as F100-PW-229 from Pratt & Whitney, and main engine components including fan, high pressure compressors, combustion, high pressure turbines, low pressure turbines, mixer, convergent-divergent nozzle are modeled. The cooling effect of turbine through secondary flow path are considered in engine simulation model. We develop in-house Matlab/Simulink-based engine performance analysis program capable of analyzing internal engine state and compare it with GASTURB which is generally used as a commercial engine analysis program.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.3 s.258
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• pp.292-299
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• 2007

In gas turbine technology, the flame stability is inherently greater in conventional diffusion type combustion over a wider range fuel to oxidizer ratio. However, premixed type combustion which has narrow flame stability region, is widely used due to environmental reason. It has been observed in experiments that combustion instability of low frequency (${\sim}10Hz$) results from the modulation of equivalence ratio at fuel injection hole when a pressure fluctuation propagates upwards along the channel of the burner under an unchoked fuel flow condition. In this study, a commercial program was used to determine how the fuel flow rate changed with respect to the pressure, velocity of the fuel flow and the mass fraction in a choked and an unchoked condition. The calculation focuses on the upstream of the dump plane to know how the forced pressure with the fuel injection conditions affects the modulation of the equivalence ratio. Therefore, it is found that pressure fluctuation leads to oscillation of mass flow rate and then results in equivalence ratio modulation under the unchoked fuel flow condition.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.250-257
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• 2007

The development of aircraft engine requires a lot of time and cost to estimate system attributes such as performance, reliability, stability and life. A virtual engine test based on "Numerical test cell" can extremely reduce the time and cost for the development of a hardware by coupling multidisciplinary analyses. This paper presents the development activities of full engine simulation programs in U.S.A. and Europe. NASA Glenn research center of U.S.A. leads the development efforts of NPSS(Numerical Propulsion System Simulation) by assembling the existing codes and improving their functions. VIVACE (Value Improvement through a Virtual Aeronautical Collaborative Enterprise), a consortium of universities, research centers and companies in Europe is developing the PROOSIS(PRopulsion Object Oriented SImulation Software) by integrating the various programs of the institutes. The capability for the domestic development is also estimated by surveying the current status.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.6
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• pp.96-103
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• 2004

Sought a set of component performance lines from experiment data or some data supplied in the engine manufacturer to improve the traditional scaling method and suggested a map scaling method that construct component performance lines newly using polynomial equations of MATLAB program. In this study, applied technique that is proposed newly to PT6A-62 that verified technique that is proposed newly using experiment data of small. size turboshaft engine, and is actuality aircraft engine. In identification of the component maps of the turboprop engine, the simulated performance using the proposed scaling method was compared with the real engine performance data and the performance using the traditional scaling method.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.335-338
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• 2010

The moisture in the atmosphere exerts a lot of influence upon Gas turbine engine performances. There is a noticeable influence of wet air at the summer sea level, high flight mach number and low engine rpm increasingly. An altitude Engine Test Facility is used to accomplish the engine performance tests at dry air condition and wet air condition, through which engine performance results is revealed. In the result, net thrust and specific fuel consumption measured -2.826% and 1.325%, respectively at wet air condition compared to dry air condition.

• Journal of Aerospace System Engineering
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• v.15 no.1
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• pp.32-39
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• 2021

Electric propulsion aircraft are being actively researched in the aviation field in recent years to solve environmental and noise problems caused by existing gas turbine engine. In particular, research on a thrust motor as a core component of an electric power propulsion system and an inverter for driving it is actively being conducted. In this paper, a motor with high specific power is selected to determine characteristics of aircraft that are sensitive to weight and volume. Power loss of the inverter is then simulated. In the simulation, the selected motor and power device were modeled using PSIM, a power electronics analysis tool. Inverter power loss according to switching frequency was then analyzed.