http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
항공기 결빙 액적장 해석을 위한 비정렬 격자 기반의 CFD 기법
정기영(K.Y. Jung),명노신(R.S. Myong),정성기(S.K. Jung) 한국전산유체공학회 2012 한국전산유체공학회 학술대회논문집 Vol.2012 No.11
Ice accretion on aircraft surface plays a critical role in the performance and safety of aircraft. Especially, changes in the external shape of the aircraft due to ice accretion can greatly deteriorate the aerodynamic performance of aircraft. In the study, air flow and droplet impingement codes for prediction of ice accretion on aircraft are developed. A finite volume method CFD solver based on unstructured grids is developed to solve the dean air flow and Eulerian-based droplet field. The codes are then compared with NASA IRT experimental data and computational results obtained by a state-of-the-art icing code. The present prediction is shown to be in close agreement with IRT data.
비정렬 격자 기반의 결빙 액적 해석을 위한 유한체적 기법
정기영(K. Y. Jung),정성기(S. K. Jung),명노신(R. S. Myong) 한국전산유체공학회 2013 한국전산유체공학회지 Vol.18 No.2
Ice accretion on the solid surface is an importance factor in assessing the performance of aircraft and wind turbine blade. Changes in the external shape due to ice accretion can greatly deteriorate the aerodynamic performance. In this study, a three-dimensional upwind-type second-order positivity-preserving finite volume CFD scheme based on the unstructured mesh topology is developed to simulate two-phase flow in atmospheric icing condition. The code is then validated by comparing with NASA IRT experimental data on the sphere. The present results of the collection efficiency are found to be in close agreement with experimental data and show improvement near the stagnation region.
정기영(K.Y. Jung),안국빈(G.B. Ahn),정성기(S.K. Jung),명노신(R.S. Myong),조태환(T.H. Cho),신훈범(H.B. Shin),정주현(J.H. Jung),최영호(Y.H. Choi),김정훈(J.H. Kim) 한국전산유체공학회 2011 한국전산유체공학회 학술대회논문집 Vol.2011 No.5
Ice accretion on aircraft surface can greatly deteriorate the safety of aircraft. In particular, it can be a cause of impediment for aircraft performances such as aerodynamic characteristics, control, and engine. Numerical simulation of icing accretion based on the state-of-art CFD techniques can be alternative to expensive icing wind tunnel test or flight test. In this study, icing conditions are defined in order to predict the ice accretions around the air intake of aircraft. Then the range and amount of ice accretion on the intake in icing wind tunnel were investigated. In addition, a study on the size effect of icing wind tunnel was conducted in order to check the compatibility with the real in-flight test environment.
정기영(K.Y. Jung),안국빈(G.B. Ahn),명노신(R.S. Myong),조태환(T.H. Cho),정성기(S.K. Jung),신훈범(H.B. Shin) 한국전산유체공학회 2012 한국전산유체공학회지 Vol.17 No.2
Ice accretion on the surface of aircraft in flight can adversely affect the safety of aircraft. In particular, it can cause degradation of critical aircraft performances such as maximum lift coefficient and total pressure recovery factor in engine air intake. In this study, computational prediction of ice accretion around a rotorcraft air intake is conducted in order to identify the impingement region with high droplet collection efficiency. Then the amount of ice accretion on the air intake, which is essential in determining the required power of ice protection system, is calculated. Finally, the effect of icing wind tunnel size is investigated in order to check the compatibility with the real in-flight test environment.
전산 기법을 이용한 공대공 유도 미사일의 고앙각 공력특성 예측
노국현(K.H. Noh),정기영(K.Y. Jung),명노신(R.S. Myong),박정호(J.H. Park) 한국전산유체공학회 2012 한국전산유체공학회 학술대회논문집 Vol.2012 No.5
Efficient prediction of aerodynamic characteristics remains important in the preliminary design stage of missile. In particular unexpected side force and yawing moment can occur by asymmetric vortex in air-to-air missiles with slender shaped body at high angle of attack. In this study, a CFD code based on the Navier-Stokes equations was used to calculate the flowfields at high angle of attack, while a semi-empirical method was used at low angle of attack. It was shown that side force and yawing moment at high angle of attack can be predicted with reasonable accuracy by a CFD method based on the concept of applying different surface roughness in forebody.
박지호(J.H. Park),정기영(K.Y. Jung),명노신(R.S. Myong) 한국전산유체공학회 2013 한국전산유체공학회지 Vol.18 No.3
A significant change in aerodynamic characteristics of wind turbine blade can occur by ice formed on the surface of the blade operated in cold climate. The ice accretion can result in performance loss, overloading due to delayed stall, and excessive vibration associated with mass imbalance. In this study, the impact of ice accretion on the aerodynamic characteristics of NREL 5MW wind turbine blade sections is examined by a CFD-based method. It is shown that the thickness of ice accretion increases from the root to the tip and the effects of icing conditions such as relative wind velocity play a significant role in the shape of ice accretion. In addition, the computational results are used to assess the degradation in the lift and drag coefficients of the blade sections.
CFD 및 BEM 기법을 이용한 풍력 블레이드의 결빙에 의한 공력특성 변화 전산 예측
박지호(J.H. Park),안국빈(G.B. Ahn),정기영(K.Y. Jung),명노신(R.S. Myong) 한국전산유체공학회 2012 한국전산유체공학회 학술대회논문집 Vol.2012 No.11
A significant change in aerodynamic characteristics can occur by ice accretion on the surface of wind turbine blade due to low temperature in cold climate. In particular, it will result in the loss in electricity production through a negative influence on lift and drag. In this study, the impact of ice accretions on the aerodynamic characteristics of wind turbine blade sections is first investigated. The results are then used to predict 3D aerodynamic characteristics of wind, turbine blade through the blade element momentum method. It is shown that the thickness of ice accretion increase and the lift-to-drag ratio decrease from the root to the tip, and, as a result, the power coefficients decrease significantly.
풍력 블레이드의 표면발생 결빙에 의한 공력 영향성 전산 예측
박지호(J.H. Park),안국빈(G.B. Ahn),정기영(K.Y. Jung),명노신(R.S. Myong) 한국전산유체공학회 2012 한국전산유체공학회 학술대회논문집 Vol.2012 No.5
A significant change in aerodynamic characteristics can occur by ice accretion on the surface of wind, turbine blade due to low temperature in cold climate. In particular, it will result in the loss in electricity production through a negative influence on lift and drag. In this study, the impact of ice accretions on the aerodynamic characteristics of wind, turbine blade sections is examined by computational methods. It is shown that the thickness of ice accretion increase and the lift-to-drag ratio decrease from the root to the tip.