• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.4
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• pp.253-260
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• 2013

Ice accretions on the surface around a rotorcraft air intake can deteriorate the safety of rotorcraft due to the engine performance degradation. The computational simulation based on modern CFD methods can be considered extremely valuable in analyzing icing effects before exact but very expensive icing wind tunnel or in-flight tests are conducted. In this study the range and amount of ice on the surface of anti-icing equipment are investigated for heat-on and heat-off modes. It is demonstrated through the computational prediction and the icing wind tunnel test that the maximum mass and height of ice of heat-on mode are reduced about 80% in comparison with those of heat-off mode.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.6
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• pp.481-486
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• 2011

The evaluation of supercooled water droplet impingement characteristics of full-scale aircraft components in wind tunnels under icing conditions has been severely limited by the relative size of the component and the test facility. The concept of truncated airfoil sections has been suggested in order to extend the operational range of icing tunnels. With proper deflection of the small trailing-edge flap on the truncated airfoil the local pressure distribution may remain very close to that of the full-scale airfoil. In this study the shape of a truncated flapped airfoil is investigated for various deflection angles. To validate the truncated flapped airfoils, air flow and collection efficiency over the truncated airfoil are compared with the results of the full-scale airfoil obtained from the state-of-the-art icing simulation code.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.2
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• pp.146-156
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• 2012

In-flight icing remains as one of the most persistent hazards for aircraft operations. The effect of icing on aircraft performance and safety has to be evaluated during the development and airworthiness certification process. The scaling method is a procedure to determine the scaled test conditions in icing wind tunnels in order to produce the same result as when the reference model is exposed to the desired cloud conditions. In this study, a scaling program is developed to provide an easy-to-use tool to the aero-icing community. The Olsen and Ruff 4th methods are employed for this purpose and the velocity is calculated by matching the dimensionless Weber number. To validate the program, the results are compared with the NASA scaling results. The scaling examples based on FAR (Federal Aviation Regulation) Part 25 Appendix C are also presented. Finally, a validation study using a state-of-the-art icing simulation code FENSAP-ICE is presented.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.11
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• pp.944-951
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• 2018

Artificial icing test and wind tunnel test can be performed to reduce the development period when a rotorcraft is required operation under icing situations. Artificial icing test of the KUH(Korean Utility Helicopter) was performed in advance to verify anti-icing and de-icing performance before natural icing test. Although high-precision sensor, the CCP(Cloud Combination Probe) is used to measure icing test condition parameters such as LWC(Liquid Water Content) and MVD(Median Volume Diameter), the measured values need to be verified in various methods due to the possibility of uncertainties which are the test atmosphere environment, sensor errors, and etc. The calculated LWC from the ice thickness cumulated on the fuselage of the KUH is compared to the measured value by CCP, and the results show the effective indirect method to check the test conditions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.9
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• pp.714-719
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• 2013

A turboprop aircraft for this study is required to operate at icing condition in order that it performs its given mission. So an air intake system of the turboprop aircraft should be designed and verified not only to provide the maximum possible total pressure at engine inlet at normal flight condition, but also to include an inertial separator which protects Foreign Object Debris (FOD) like ice or snow at icing condition from entering into the engine inlet screen which can cause or lead an catastrophic engine failure like engine flame-out or severe damage. So an air intake assembly incorporating a variable geometry inertial separator has been designed and then CFD/structural analysis for the assembly was performed to see its design results. Then 35% scaled model of the air intake assembly was manufactured and wind tunnel test was done. This paper describes the detailed design results for the aerodynamic design, analysis and wind tunnel testing during the development process of the air intake assembly.