• Journal of the Korea Institute of Military Science and Technology
• /
• v.15 no.1
• /
• pp.101-110
• /
• 2012

The side jet effects between jet flow and free-stream on a missile body were investigated by experimentally and numerically for modeling aerodynamic coefficients in pitch plane. K-factors for normal force and pitching moment were introduced to estimate the side jet effects. The main parameters of the jet interaction phenomena were angle of attack, jet pressure ratio, Mach number and jet bank angle. The K-factors for normal force coefficient and pitching moment coefficients in pitch plane were analysed.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03a
• /
• pp.245-250
• /
• 2008

For simulation of a wing unfolding motion for the various aerodynamic conditions, equation governing unfolding motion and moments applying to the unfolding wing were modelled. Aerodynamic roll moment consists of the static roll moment and the damping moment, which were obtained through wind tunnel tests and numerical analyses respectively. Panel method was used to compute the roll damping coefficient with twisted wing, whose deflection angle was equivalent to angle of attack due to the deployment motion. Roll damping coefficient is a function of angle of attack, sideslip angle, and deployment angle but not of angular velocity of deployment. Simulation with aerodynamic damping model gave more similar deployment time compared to wing deployment test results.

• 한국전산유체공학회:학술대회논문집
• /
• 2006.10a
• /
• pp.20-21
• /
• 2006

Three kinds of jet flows encountered in the practical airframe design phase are discussed in this paper. Firstly, the side jet effect on the cavity flow over the flat plate was investigated. Secondly, the aerodynamic modeling of side jet influence on body-tail configuration was presented. Computational study of the similarity parameters was done to minimize the wind tunnel test. Lastly, supersonic jet impingement on a flat plate surrounded by solid walls was simulated numerically for both axi-symmetric and three-dimensional calculations with moving body method.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.10a
• /
• pp.245-250
• /
• 2008

For simulation of a wing unfolding motion for the various aerodynamic conditions, equation governing unfolding motion and moments applying to the unfolding wing were modelled. Aerodynamic roll moment consists of the static roll moment and the damping moment, which were obtained through wind tunnel tests and numerical analyses respectively. Panel method was used to compute the roll damping coefficient with twisted wing, whose deflection angle was equivalent to angle of attack due to the deployment motion. Roll damping coefficient is a function of angle of attack, sideslip angle, and deployment angle but not of angular velocity of deployment. Simulation with aerodynamic damping model gave more similar deployment time compared to wing deployment test results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.04a
• /
• pp.476-476
• /
• 2009

Periodic vortex separations generate periodic vertical forces acting on a trailing edge of an airfoil. When a natural frequency of the trailing edge of the airfoil is close to a vortex shedding frequency, an amplitude of the edge oscillation becomes maximal; it makes intensive noise called singing. Motion of the trailing edge may also feedback to the vortex shedding so that self-sustained oscillation appear, and a resonant frequency is locked in some interval of the speed of the incident flow. In this study, a theoretical model is proposed and applied for modeling an airfoil singing. Results are compared with experimental measurements which are carried out in an anechoic wind tunnel.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.20 no.2
• /
• pp.115-121
• /
• 2010

Periodic vortex separations generate periodic vertical forces acting on a trailing edge of an airfoil. When a natural frequency of the trailing edge of the airfoil is close to a vortex shedding frequency, an amplitude of the edge oscillation becomes maximal; it makes intensive noise called singing. Motion of the trailing edge may also feedback to the vortex shedding so that self-sustained oscillation appears, and a resonant frequency is locked in some interval of the speed of the incident flow. In this study, a theoretical model is proposed and applied for modeling an airfoil singing. Results are compared with experimental measurements which are carried out in an anechoic wind tunnel.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.40 no.3
• /
• pp.193-200
• /
• 2012

A numerical analysis is carried out in order to obtain aerodynamic data of the ski jump. The body modelling of Korean people is used in the numerical simulation and the result is validated by comparing it with the wind tunnel experiment. A flying posture, which provides the maximum lift-to-drag ratio, is found by analyzing the aerodynamic coefficients of various flight conditions. The result of the present study can be applied to fixing the postures of Korean ski players and is expected to advance the national sports science.

• Korean Journal of Computational Design and Engineering
• /
• v.2 no.2
• /
• pp.85-92
• /
• 1997

An axial flow fan design system has been made by integrating the self-developed programs and I-DEAS. By using the system, an axial flow fan was designed, manufactured and verified through the wind tunnel experiments in coorperation with a refrigerator appliance division. It has been shown that the optimal design without the ambiguity of the design parameters can be possible by the three-dimensional flow simulations using a self-developed CID code, FANS-3D. (Flow Analysis code using Navier Stokes aguations in Three-Dimensional curvilinear coordinates). By virtue of the fluency of the data flow, an optimally designed fan which satisfies design conditions can be selected in a short time and less cost. The manufacturing processes of a Mock-up and an injection molding die have been automated through the self-made interface programs which connnect from the start to the end. It has been shown that the newly developed fan by this system has a superior performance characteristics to an existing fan.

• 한국전산유체공학회:학술대회논문집
• /
• 2003.08a
• /
• pp.120-125
• /
• 2003

Recently, lateral jet has been adopted as an effective control device for high maneuverable tactical missiles in supersonic regime. Aerodynamic interference caused by the lateral jet can be categorized into two phenomena : local interaction redistributing surface pressure near the jet exit region and downstream interaction affecting tail control effectiveness. As part of on-going research, this paper deals with the aerodynamic modeling to predict the variation of force and moment when lateral jet of is activated on the missile body. For this purpose, a series of numerical simulation has been performed and the results are presented. Using the information obtained by CFD, aerodynamic model of preliminary level has been constructed and is reviewed. Some relevant comparison with wind tunnel tests are presented.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2010.04a
• /
• pp.488-491
• /
• 2010

본 논문에서는 돌풍응답경감제어 효과 검증을 위한 풍동시험에 사용될 유연날개에 대해 공탄성 모델, 조종면 작동기 모델, 돌풍 모델 등으로 구성되는 서보공탄성 모델링을 수행하였으며, 이에 대한 연속돌풍 응답해석을 수행하여 상용 Solver를 이용한 해석결과와 비교하여 구성된 서보공탄성 모델을 검증하였다. 또한, 유연날개의 돌풍응답을 경감하는 조종면 제어기를 설계하고, 이에 대한 수치 시뮬레이션을 수행하여 돌풍응답 경감효과를 검증하였다.