• Aerospace Engineering and Technology
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• v.10 no.2
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• pp.82-86
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• 2011

This paper presents an RF Electric field assessment at 2.290 [GHz] inside launcher PROTON M/Breeze M long fairings, produced by COMS TM. COMS intentional RE due to TM ON under fairing has been assessed considering PROTON M / BREEZE M fairing characteristics. As fairings of all launchers present similar sizes, a similar E-field level under fairing is expected for the other launchers. As a result, the RE level under faring is compliant with COMS RS limits, but is not compliant with RS requirements of the launcher PROTON M/Breeze M.

• Journal of Aerospace System Engineering
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• v.16 no.2
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• pp.25-32
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• 2022

A cab roof fairing is a device that reduces the drag coefficient of a commercial vehicle, by controlling the resistance of flow separation occurring in the front when the commercial vehicle travels. Commercial vehicles are designed to facilitate aerodynamic resistance that cannot be avoided from the driving direction of the vehicle, because they must structurally load containers in the rear. For this reason, it is closely related to oil costs and environmental pollutants. In this study, the 3D fairing shape was designed based on the Rankine half body theory, and the design results were verified through aerodynamic analysis.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.11
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• pp.900-907
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• 2013

Payload fairing(PLF) protects satellites and related equipment from the external environment. They are separated before the satellite separation. Payload fairing made of composite sandwich materials due to their considerable bending stiffness and strength-to-weight ratio. Payload fairing have compression, shear and bending load during the flight. In this study, To check the strength of PLF and connected part, structural test of PLF accomplished using an actuator and a fixture. Purpose of structural test is to verify the strength of PLF in force of separation spring and combination structural load applied. Test result shows that the PLF have an acceptable margin of safety for the combination structural load and force of separation spring.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.12
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• pp.1129-1134
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• 2007

Payload fairing protects satellites and electrical equipments from the external environment. Payload fairing is jettisoned before satellite separation. Assembly frame for the separation of payload fairing were assembled with shear bolts. The role of shear bolts is to support structural load during flight and they are cut by explosion of pyro. The assembly frame which is connected by shear bolts is separated after the cutting of shear bolts. In this paper, structural tests and analysis were done for the design of the shear bolt. Compression, bending and shear load apply to the hardware including assembly frame. Test results showed that design of the shear bolt satisfied both structural strength for the support of flight load and required low strength for the cutting of shear bolts.

• Composites Research
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• v.17 no.3
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• pp.15-22
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• 2004

Acoustic load generated by rocket propulsion system is one of major dynamic loads during lift-off phase so that it causes the structural failure and electronic malfunction of payloads. Acoustic loads can be greatly reduced by an appropriate acoustical design of nose faring structures. This paper deals with the acoustical design of the nose fairing structure for launch vehicle. It is well known that a honeycomb sandwich structure is a poor sound insulator because of its high specific stiffness. In this paper, the sound transmission characteristics of four kinds of honeycomb structures for noise fairing were investigated by means of numerical and experimental ways. In order to estimate transmission loss, infinite plate theory by Moore and Lyon and statistical energy analysis (SEA) method were used. The predicted results showed a good agreement with measured ones. These enabled us to determine a proper core material for nose fairing, which shows good sound insulation performance per weight.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.12
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• pp.1146-1151
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• 2011

Acoustic load from rocket propulsion system is main source of random vibration working on the payload. To protect payload from this acoustic load, additional APS(acoustic protection system) is generally applied. Noise reduction capacity of APS can be verified through acoustic test and vibro-acoustic coupled analysis. This paper compared the results of acoustic test and vibro-acoustic coupled analysis about KSLV-I payload fairing with APS.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.250-253
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• 2005

This paper is investigates the separation shock of payload fairing. Separation test of subscale PLF using half separation device and half PLA is performed. Resulting shock loads at equipment bay and fairing joint are measured. Pyroshock estimation is performed using AUTOSEA Pyroshock Module. Input data to analysis model is obtained from the separation test results of subscale PLF. And model of AUTOSEA is updated comparing results between tests and analysis.. This enables us to validate the AUTOSEA model. Tuned model of subscale PLF and separation device is used to update full scale model, and the shock analysis result of full scale model is estimated in this paper. This paper also discusses the results regarding the difficulty of structural modeling and its numerical implementation in AutoSEA2 Software.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.1
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• pp.85-91
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• 1996

In the elM construction of naval architecture industry, ship hull surface modeling is critical process of design/manufacture process. This paper describes a fairing process of ship waterlines to represent boundary curves which are input data of surface modeling. Among the fairing methods, Sapidis's method and Rong's method are used in sequential to fair the boundary curves. Also it proposed four methods of determining the magnitude of end tangent vector. Among the four end tangents the best one is chosen by comparing with the shape of near curves. An application to the actual ship hull is given as an example.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.113-116
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• 2006

In this paper, the fairing effects on the aerodynamics stability of basic plate-girder sections are investigated trough wind tunnel tests. As basis sections, two types of $\pi$-type shape sections with aspect ratios(D/B) of 1/5 and 1/10 are employed as the basic sections. And three types of triangular fairings are applied such as right-angled triangle(F1), inverted right-angled triangle(F2) and regular triangle(F3). The effects of attack angle on the dynamic response of each section are also investigated. As the results of experiments, fairings F2 is most effective to suppress flutter phenomenon or vortex induced vibration among three types of fairings.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.189-192
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• 2002

The autoclave process is frequently utilized in the manufacturing of aircraft parts because of the low void content and high fiber volume fraction. However, due to the slow curing process (5∼8 hours per part) and it's limited producibility for complicated shape, this process is very expensive and applied to the relatively simple geometry structures. RTM is considered as an alternative process to overcome the limitation of autoclave process. In this study, the idea of RTM application on the secondary Fairing structure of aircraft has been proved to be technically feasible and very cost effective by changing the multiple part of subassembly into one integral composite structure.