• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2010년 춘계학술대회논문집
• /
• pp.43-49
• /
• 2010

Aerodynamic design of the vane type multi-function probe was tried by using CFD and wind tunnel test for the MALE UAV and small business jets. The present multi-function probe can measure total pressure, static pressure and angle of attack by using rotating vane. Therefore major performances are determined by aerodynamic characteristics of vane. In oder to design the sensor compatible to the requirement, aerodynamic characteristics of sensors was investigated by using CFD and dynamic response analysis was also performed for trasient performance. The final aerodynamic performance was measured by the wind tunnel test at Aeorsonic and the results successfully used for the design of vane type multi-function air data sensor.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2010년 춘계학술대회논문집
• /
• pp.431-436
• /
• 2010

Recently, several open source codes for computational fluid dynamics (CFD) have been emerged and are spreading fast. Our group has chosen OpenFOAM as a platform to develop our own in-house code. In this paper, we would like to share the information on the codes and what we have experienced so far. We introduce several features of OpenFOAM, which include the performance compared with commercial packages, estimation for current user population and our own prospect for future improvement in performance and growth in user population. In addition, we briefly introduce our experience gained in embedding the level set method into the OpenFOAM.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2010년 춘계학술대회논문집
• /
• pp.404-411
• /
• 2010

The present paper deals with the continuous work of extending multi-dimensional limiting process (MLP), which has been quite successfully proposed on two- and three-dimensional structured grids, onto the unstructured grids. The basic idea of the present limiting strategy is to control the distribution of both cell-centered and cell-vertex physical properties to mimic a multi-dimensional nature of flow physics, which can be formulated as so called the MLP condition. The MLP condition can guarantee a high-order spatial accuracy without yielding spurious oscillations. Recently, MLP slope limiter was proposed based on the MUSCL-type reconstruction in two-dimensional case and it can be readily extended to three-dimensional case. Through various numerical analyses and extensive computations, it is observed that the proposed limiters are quite effective in controlling numerical oscillations and very accurate in capturing both discontinuous and continuous multi-dimensional flow features on 3-D tetrahedral grids.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2010년 춘계학술대회논문집
• /
• pp.136-141
• /
• 2010

This study describes effects of width contraction in vaneless diffuser on the performance of centrifugal compressors using commercial CFD code. Numerical analysis for three different diffusers such as Parallel, half contraction, and full contraction was performed. The results show that the performance of the centrifugal compressor is improved through the use of the diffusers with width parallel in high flow rate. The width contraction of diffusers is influenced static pressure rises. Comparison with the experimental data shows agreement.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2010년 춘계학술대회논문집
• /
• pp.17-20
• /
• 2010

An aerial target system is used for the purpose of experimental test and fire training of missile that newly developed and in mass production. Since the target drones of aerial target systems are monopolized by several major countries so that they are selling at a high price. In this paper, we present the CFD simulation results on a new target drone that Kyungan co. ltd is developing with their own technologies. The presented CFD simulation was conducted in the same conditions of a wind tunnel tests and we could obtain the simulation results of the lift and drag values were in errors by less than 15 percent compared to the experiment. The simulation results were used to determine the modified shapes of new prototype target drone that could fly safely.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2010년 춘계학술대회논문집
• /
• pp.201-207
• /
• 2010

In this study, we calculated arc discharges happened in high-voltage circuit breakers for understanding the complex physics and the probability of thermal breakdown. The four main parts of arc model for this virtual-reality are radiation, PTFE abaltion, Cu evaporation and turbulence. Among these important parts the turbulence model can be critical to the reliability of computation results during high-current period because the plasma flow is affected by high eat energy and mass momentum. Two kinds of turbulence model, zero-equation model and two-equation model, are applied for these calculations and are compared with the measured pressure data inside a chamber.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2010년 춘계학술대회논문집
• /
• pp.28-31
• /
• 2010

In order to clarify the characteristics of power performance and uncertainty of a wind turbine, an investigation was performed in Hangyeong wind farm, Jeju island, Korea. Data were collected for 12 months from Feb. 2, 2008 to Jan. 1, 2009. This study was conducted on the base of the International standard, and observed the methods of mesurement and evaluation form IEC 61400-12. As a result, power performance curve was calculated by measured data and compared with the sixth unit of VESTAS V90-3.0MW in Hangyeong wind farms. In consequence of this paper, uncertainty was estimated from 7% to 14% on the range of the average wind speed from 4m/s to 11m/s.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2010년 춘계학술대회논문집
• /
• pp.446-447
• /
• 2010

최근 개발된 니켈 초합금 금속폼은 기존의 매연저감장치 신소재로 여겨지고 있다. 금속폼은 세가지 두드러진 특징을 갖고 있다. 첫째, 금속폼은 큰 기공의 다공성 매질로써 매연을 포집하여 축적할 수 있는 용량이 기존 필터에 비해 상대적으로 크며 그로인하여 재생 시 연소 안전성이 두드러진다. 둘째, 복잡하고 굴곡있는 기공 구조와 큰 비표면적은 물질전달 특성을 향상시켜 촉매 적용 시 촉매의 전환성능을 향상시키고 그로 인하여 귀금속 촉매량을 줄일 수 있는 장점이 있다. 셋째, 금속폼은 다양한 기공크기를 가지며, 다양한 조합의 금속폼을 개발할 수 있어 요구 성능에 따른 최적의 필터 설계를 가능케 한다. 이번연구에서는, 금속폼의 필터 성능을 다양한 실험을 통하여 측정 평가하며, 이런 이해를 기반으로 필터로 제작하여 엔진실험벤치에서 그 성능을 검증하였다. 필터의 성능은 수트 포집효율과 그에 따른 필터의 압력강하와 촉매 활성 능력으로 평가되었다. 이러한 실험과 병행하여 금속폼에서의 수트 포집과정을 모델링하고 이를 상용 프로그램인 CFD-ACE+에 추가하여 설계전용 프로그램을 개발하였으며, 엔진실험결과와 비교 검증하였다. 본 논문에서는 금속폼의 높은 매연축적용량과 향상된 물질전달 특성이 어떻게 필터의 귀금속 촉매와 체적을 줄일 수 있는지 제시하고 있다.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2010년 춘계학술대회논문집
• /
• pp.460-463
• /
• 2010

Ice accretion on aircraft surface can greatly impair the aerodynamic performance of aircraft. As an alternative to the traditional Lagrangian particle tracking approach, an Eulerian-based droplet impingement and ice accretion code for air flows containing water droplets was developed A CFD solver was also developed to solve the clean airflow. The results of present method were compared with experimental data and previous icing codes such as LEWICE and FENSAP-ICE and were confirmed to show good agreement each other in qualitative and quantitative ways.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2010년 춘계학술대회논문집
• /
• pp.464-467
• /
• 2010

Ice accretion on aircraft surface in icing condition induces external shape changes that may result in a hazard factor for aircraft safety. In case of aircraft main wing with high lift equipment, ice accretion is observed around leading edge and flap. During the design phase, location of ice accretion and associated aerodynamic characteristics must be investigated. In this study, icing effects on aerodynamic characteristics of the main wing section of KC-100 aircraft are investigated using an Eulerian-based FENSAP-ICE code in various icing conditions.