• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.5
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• pp.1-8
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• 2002

The performance of MAV(Micro Air Vehicles) propellers is highly affected by the aerodynamic characteristics of a 2-D blade airfoil shapes. XFOIL is used to predict the lift and drag coefficients in low Reynolds Number flows. ARA-D 6%, which shows a good performance in low Reynolds Number regions, is selected as a blade airfoil. The 3-D propeller blade shape is optimized with the minimum energy loss condition, and the distribution of aerodynamic coefficients of ARA-D 6% is calculated. The designed optimal blade is compared with the Black Widow's propeller blade shape in the same conditions. The results indicate that the designed propeller installed in MAV can provide a good performance.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.1
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• pp.16-27
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• 2018

A basic numerical analysis was performed to confirm the possibility of combining a dual bell nozzle and an Expansion-Deflection(E-D) nozzle. The dual bell nozzle was designed based on the first-stage nozzle of the Korean Space Launch Vehicle that is being developed, and the E-D nozzle concept was applied to the dual bell nozzle. The inlet condition was analyzed by applying eight types of frozen flow analysis, and k-${\omega}$ SST was selected as the turbulence model. The number of optimal grids was obtained as 240,000 through the grid sensitivity analysis. As a result, it was confirmed that the transition altitude increased owing to over-expansion when the E-D nozzle concept was applied to the dual bell nozzle, and the specific impulse gain was obtained at high altitudes compared with the KSLV-II first-stage engine.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.5
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• pp.455-461
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• 2015

A high-pressure fuel pump is a key component in a gasoline direct injection (GDI) engine; thus, understanding its flow characteristics is essential for improving the engine power and fuel efficiency. In this study, AMESim, which is a hydraulic analysis program, was used to analyze the performance of the high-pressure fuel pump. However, since AMESim uses a one-dimensional model for the system analysis, it does not accurately analyze the complicated flow characteristics. Thus, Fluent, computational fluid dynamics (CFD) software, was used to calculate the flow rates and net forces at the intake and discharge ports of the high-pressure fuel pump where turbulent flow occurs. The CFD analysis results for various pressure conditions and valve lifts were used as look-up tables for the AMEsim model. The CFD analysis results complemented the AMEsim results, and thus, improved the accuracy of the performance analysis results for the high-pressure fuel pump.