• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.5
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• pp.101-106
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• 2006

This paper describes performance design of a solid rocket motor on which thrust cut-off system is installed, and evaluates performance of a rocket motor according to a size of TCO ports. TCO system installed on motors was made to carry out firing tests, and the trend of thrust due to various sizes of TCO port was analyzed to find the existence of the port size for maximum reversal thrust. Conservation equations were used to design performance of motors and to analyze test results. This technique for performance design will be usefully applied to the design of similar TCO systems.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.53-56
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• 2006

This paper describes performance design of a solid rocket motor on which thrust cut-off system is installed, and evaluates performance of a rocket motor according to a size of TCO ports. TCO system installed on motors was made to carry out firing tests, and the trend of thrust due to various sizes of TCO port was analyzed to find the existence of the port size for maximum reversal thrust. Conservation equations were used to design performance of motors and to analyze test results. This technique for performance design will be usefully applied to the design of similar TCO systems.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.1
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• pp.12-18
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• 2021

In this study, the performance modeling of MT30 gas turbine engine is performed. The design point is determined, and the component performance maps to which the scaling technique is applied are generated using standard maps provided by the commercial program. Off-design point performance analysis is performed with the generated performance model, and this is compared with the performance deck data of the engine. It is confirmed that the data of the performance maps generated by the one-point scaling method had some errors from the performance deck data, and it is determined that correction is necessary to increase the accuracy of the performance model. Therefore, the off-design point analysis is performed by creating the correction performance model in a manner that obtains the scaling factors for each operating point(off-design point) according to the high pressure spool speed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.8
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• pp.2167-2176
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• 1994

This paper presents some useful design criteria for the turbine cogeneration system through both the design and off-design analysis. Comparative analysis of the part load performance is carried out for several gas turbines which have different design parameters represented by the turbine inlet temperature and pressure ratio. It is shown that the variation in part load efficiency considerably depends on the design parameter. The off-design operation of the heat recovery steam generator is simulated by introducing adequate assumptions for the heat transfer process. It is turned out that the design parameters of heat recovery steam generator should be determined by considering the favorable operation at the off-design conditions.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.644-648
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• 2004

In the present study were examined numerically and experimentally the off-design performance characteristics on an axisymmetric plug nozzle with variable throat area. In this nozzle concept, its throat area can be changed by translating the plug into the axial direction. First, a mixed-expansion plug nozzle, in which two expansion parts are arranged both inside and outside, was designed by means of the method of characteristics. Second, the CFD analysis was verified by the cold-flow wind tunnel test. Third, its performance characteristics were evaluated over a wide range of pressure ratio from half to double throat area through the design point, using the CFD code verified by the wind tunnel tests. It was made clear from the study that not so critical thrust efficiency losses were found and the maximum thrust efficiency loss was at most approximately 5 % under off-design conditions without external flow. This result shows that a plug nozzle can give the altitude compensation even under off-design geometry operations. However, shock waves were observed in the inner expansion part under the doubled throat area operation and thus some thermal problems may be caused on the plug surface. Furthermore, collapse of cell structure on the plug surface was observed with external flow (around Mach number 2.0) as it became lower pressure ratio below the design point and the fact may result in big efficiency loss regardless of geometrical configuration.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.2171-2180
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• 1991

An analysis model for off-design performance of radial inflow turbines with or without variable area guide vane is developed, where two important factors in loss models, total pressure ratio between variable area guide vane exit and scroll casing inlet and rotor loss coefficient are determined without experimental data. The analysis results show that the predicted trends with or without variable area guide vane are consistent with the experimental observations. The comparison of present method with the well-known NASA off-design performance analysis program shows that the mass flow rate and static efficiency by present analysis are in good agreement with those by the NASA program. Therefore, this method can be used to predict off-design performance of radial inflow turbines with validity of the loss models used by present analysis.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.222-226
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• 2006

The purpose of this study is to analyze both the design and off design performance simulation of the PW206C turbo shaft engine used in the development of the smart UAV (Unmanned Ariel Vehicle) by KARI(Korean Aerospace Research Institute). Its mainly aims to investigate performance behavior at the un-installed and installed conditions. The ways employed to be able to analyze the performance extensively were mainly carried out by comparison of performance simulation results from both the commercial program 'GASTURB 9' using compressor maps generated by Genetic algorithms (GAs) or Scaling Method, and the engine manufacturer's program 'EEPP'. Off-design performance analysis was performed through matching of both mass flow and work between engine components. The set of performance simulations of the developed analytical models was performed by a commercial program package (GASTURB 9) that provides great flexibility in the choice of independent variables of the overall system. The results from the simulations are used to compare turbo shaft engine (PW206C) performance data obtained by the EEPP. At un-installed condition, it was found that the results with the compressor map generated by GAs were relatively agreed well than those with the compressor map generated by the Scaling Method. The performance calculation results using the compressor map generated by GAs were compared at un-installed condition and installed conditions with ECS-off and ECS-Max in variation of altitude, gas generator speed and flight speed.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.1
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• pp.70-79
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• 2013

In this work, a steady-state performance modeling and off-design performance analysis of the 2-spool separate-flow turbofan engine named (BR715-56) which is a power plant for the narrow body commercial aircraft is carried out for engine performance behaviors investigation and condition monitoring using a commercial code MATLAB/SIMULINK. Firstly, the engine component maps of fan, high pressure compressor, high pressure turbine and low pressure turbine are generated from similar component maps using the scaling method, and then the off-design performance simulation model is constructed by the mass flow matching and the work matching between components. The model is developed using SIMULINK, which has advantages of easy steady-stare and dynamic modelling and user friendly interface function. It is found that the off-design performance analysis results using the proposed model are well agreed with the performance analysis results by GASTURB at various operating conditions.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.24-29
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• 1999

The purpose of this study is to develop a method of applying response surface analysis to trade-off techniques for the conceptual design of armored vehicle. The problem areas of concern are the use of this method in the selection of optimum design points when user requirements are in conflict. The application of this method to trade-offs of performance parameters in terms of weight are presented.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.1
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• pp.66-75
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• 2000

The purpose of this study is to develop and illustrate methods of applying trade-off techniques to landing craft air cushion design evaluation. The problem areas of concern are the application of quantitative analytical methods to conceptual design. The interrelationships between composite system measures and selected performance requirements(speed, cruising range, cargo etc.) are analyzed and the expressions for gross weight are developed as functions of performance parameters. Trade-offs of performance parameters in terms of weight are then calculated. The application of these results to evaluation of Require Operational Capabilities are illustrated.