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Original Article
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ROTATION/CURVATURE CORRECTION IN AERODYNAMIC PREDICTION OF AXISYMMETRIC BODIES AT HIGH ANGLES OF ATTACK
높은 받음각에서 축대칭 물체의 공력 해석을 위한 회전/곡률 보정
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B.K. Park, J. Park, D. Kim, H. Yang, S. Lee, J.S. Park
박병규, 박재형, 김동욱, 양현욱, 이승수, 박진석
- This paper present an enhanced computational analysis of tangent-ogive cylinder projectile at high angles of attack, incorporating a rotation/curvature(RC) correction to the …
- This paper present an enhanced computational analysis of tangent-ogive cylinder projectile at high angles of attack, incorporating a rotation/curvature(RC) correction to the k-ω SST RANS turbulence model. The empirical constants in Menter’s RC correction are optimized using Bayesian optimization to improve surface pressure predictions, particularly on the leeward side. These constants are trained on Lamont’s experimental data for a projectile with a nose fineness ratio of 3.5 at an angle of attack of 20° and a Reynolds number of 4.0×106 based on diameter. The improved correction is then validated on Tinling’s experimental data, which involves a slightly shorter nose with fineness ratio of 3.0, and shows better agreement with the measured surface pressure distribution. - COLLAPSE
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ROTATION/CURVATURE CORRECTION IN AERODYNAMIC PREDICTION OF AXISYMMETRIC BODIES AT HIGH ANGLES OF ATTACK
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Original Article
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MULTI-OBJECTIVE DESIGN OPTIMIZATION OF REENTRY CAPSULE USING A MACHINE LEARNING-BASED AERO-THERMODYNAMIC SURROGATE MODEL
기계 학습 기반 열공력 대리모델을 이용한 재진입 캡슐의 다목적 형상 최적 설계
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S. Kang, J. Gwon, H. Yeo, H. Nam, K.H. Kim
강성원, 권준하, 여훈정, 남한솔, 김규홍
- This study presents a rapid and efficient analysis framework for the design of reentry vehicles operating in hypersonic flow environments, by proposing …
- This study presents a rapid and efficient analysis framework for the design of reentry vehicles operating in hypersonic flow environments, by proposing a multi-objective optimization method based on machine learning surrogate models. While computational fluid dynamics (CFD) provides highly accurate results, its high computational cost makes it impractical for early design phases where a wide range of flow conditions and geometric variations must be explored iteratively. To address this limitation, surrogate models based on Kriging and deep learning were developed using sample data generated from empirical aero-thermodynamic models that represent the aerodynamic and thermal characteristics of reentry vehicles. These surrogate models were then integrated with a genetic algorithm to enable rapid optimization. The results demonstrate that the surrogate models can reliably replace the empirical models and offer significant advantages in terms of computational efficiency, confirming their potential as practical design tools at the engineering level. - COLLAPSE
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MULTI-OBJECTIVE DESIGN OPTIMIZATION OF REENTRY CAPSULE USING A MACHINE LEARNING-BASED AERO-THERMODYNAMIC SURROGATE MODEL
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Original Article
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EVALUATION OF ENERGY-EFFICIENT TWO-UNIT AIR CONDITIONING STRATEGIES IN A WAREHOUSE VIA TRANSIENT CFD ANALYSIS
비정상 전산유체역학 분석을 통한 물류 창고의 에너지 효율적인 2단위 공기조화 전략 평가
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B. Song, Y. Sun, S.M. Chang
쑹빠오, 쑨위엔위엔, 장세명
- Optimizing part-load air-conditioning strategies in climate-controlled warehouses is crucial for reducing energy consumption while maintaining environmental stability. This study evaluates four representative …
- Optimizing part-load air-conditioning strategies in climate-controlled warehouses is crucial for reducing energy consumption while maintaining environmental stability. This study evaluates four representative two-unit operation configurations selected from a fixed six-unit layout using a transient CFD model that couples air velocity, temperature, and humidity transport. The model incorporates heat and moisture transfer mechanisms and assesses each configuration based on stabilization time and spatial uniformity indicators. Results show that all two-unit scenarios achieve comparable temperature and humidity control to full-load operation. Case 3 of a point symmetry configuration offers the most uniform vertical distributions due to enhanced upper airflow and mixing. The findings support the practical feasibility of energy-saving two-unit operation strategies and provide guidance for efficient climate management in warehouse environments. - COLLAPSE
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EVALUATION OF ENERGY-EFFICIENT TWO-UNIT AIR CONDITIONING STRATEGIES IN A WAREHOUSE VIA TRANSIENT CFD ANALYSIS
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Original Article
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NUMERICAL INVESTIGATION OF TIP VORTEX REDUCTION IN A TOROIDAL PROPELLER USING CFD
CFD를 이용한 원환체 프로펠러 날개 끝 와류 감소 연구
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J.I. Kim, S.W. Jung, B.G. Baik, J.W. Ahn, S.H. Kim, M.E. Kim, I.R. Park
김제인, 정소원, 백부근, 안종우, 김상환, 김명은, 박일룡
- This paper presents a numerical investigation aimed at improving the hydrodynamic performance of a toroidal propeller and reducing tip vortex formation by …
- This paper presents a numerical investigation aimed at improving the hydrodynamic performance of a toroidal propeller and reducing tip vortex formation by varying three key design parameters: pitch ratio, camber, and vertical angle. As with conventional open propellers, the pitch ratio and camber significantly influence thrust and torque characteristics, while the vertical angle plays a critical role in both propulsive performance and tip vortex suppression. Through optimization of these parameters, the modified propeller achieves thrust performance comparable to that of the original design, with reduced torque and improved efficiency. Additionally, tip vortex generation is significantly reduced, demonstrating the potential of the toroidal propeller to effectively overcome the inherent tip vortex issues associated with conventional open propellers. - COLLAPSE
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NUMERICAL INVESTIGATION OF TIP VORTEX REDUCTION IN A TOROIDAL PROPELLER USING CFD
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Original Article
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MID-FIDELITY AERODYNAMIC ANALYSIS OF XV-15 TILTROTOR AIRCRAFT DURING TRANSIENT MANEUVER
중 충실도 기반의 XV-15 틸트로터 항공기 천이 기동 공력 해석
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Y.S. Lim, Y.S. Jung
임유상, 정용수
- This study evaluates the performance of a mid-fidelity computational fluid dynamics (CFD) method for rapid unsteady transition analysis and aerodynamic characterization of …
- This study evaluates the performance of a mid-fidelity computational fluid dynamics (CFD) method for rapid unsteady transition analysis and aerodynamic characterization of tiltrotor aircraft. Tiltrotors have recently gained attention as next-generation rotorcraft platforms, leading to active research on predicting their flight characteristics using CFD-based simulations. In this work, the Vortex Particle Method (VPM)-based solver DUST was employed, and its accuracy was validated through comparisons with experimental data and high-fidelity CFD simulations. While the rotor power prediction showed a tendency to be overestimated, the thrust predictions exhibited strong agreement. A 45-second transition flight profile, derived from coupled Reduced-Order Aerodynamic Model (ROAM)–Rotorcraft Comprehensive Analysis System (RCAS) simulations, was applied to perform both quasi-steady and unsteady transition analyses for isolated and installed rotor configurations. The results from DUST showed good consistency between the quasi-steady and fully unsteady simulations. The effectiveness of unsteady maneuver simulation using quasi-steady trim was validated by comparison with reference RCAS results obtained from unsteady trim analyses. Moreover, DUST effectively captured blade–blade tip vortex interactions and complex aerodynamic interference between the rotor and wing. - COLLAPSE
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MID-FIDELITY AERODYNAMIC ANALYSIS OF XV-15 TILTROTOR AIRCRAFT DURING TRANSIENT MANEUVER
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Original Article
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ANALYSIS OF CLEANING UNIFORMITY ACCORDING TO NOZZLE GEOMETRY AND ARRANGEMENT IN A BATCH CLEANING EQUIPMENT
배치형 세정 장비의 노즐 형상 및 배치에 따른 세정균일도 해석
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K.M. Choi, J.S. Lee, S.S. Kim, B.C. Koo, J.H. You
최강민, 이재성, 김성수, 구본찬, 유지호
- Batch-type cleaning equipment, which processes multiple wafers simultaneously, often exhibits non-uniform cleaning performance, potentially reducing yield and leading to process instability. This …
- Batch-type cleaning equipment, which processes multiple wafers simultaneously, often exhibits non-uniform cleaning performance, potentially reducing yield and leading to process instability. This study aims to improve wafer cleaning uniformity by investigating various internal piping configurations in batch-type cleaning equipment. Several pipe geometries—including offset straight tubes and U-shaped conduits—were evaluated to achieve a more uniform distribution of wall shear stress across the wafers. Computational fluid dynamics(CFD) analysis was conducted to assess wall shear stress distributions and evaluate the potential for contaminant removal. The results demonstrate that appropriate adjustments to the internal flow geometry can improve the uniformity of wall shear stress, thereby enhancing cleaning effectiveness. The improved configuration resulted in an average wall shear stress that was approximately 2.5 times higher than that of the baseline geometry, indicating enhanced cleaning performance. Furthermore, the standard deviation of the normalized wall shear stress was reduced by about 47%, demonstrating improved uniformity across the wafers. - COLLAPSE
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ANALYSIS OF CLEANING UNIFORMITY ACCORDING TO NOZZLE GEOMETRY AND ARRANGEMENT IN A BATCH CLEANING EQUIPMENT
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Original Article
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DEVELOPMENT OF AN IMPLICIT NUMERICAL METHOD FOR TWO-PHASE FLOW ANALYSIS OF PRESSURIZED WATER REACTORS
가압경수로 2상유동 해석을 위한 내재적 수치해법 개발
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P. Jobczyk, H.Y. Yoon
JobczykPatryk, 윤한영
- This study presents the development of an Implicit numerical method implemented for two-phase flows in Pressurized Water Reactors, to improve stability and …
- This study presents the development of an Implicit numerical method implemented for two-phase flows in Pressurized Water Reactors, to improve stability and decrease simulation time. It focuses on solving governing equations for the two-fluid model by treating the phase and spatial terms implicitly using implementation in CUPID. The verification of this method is performed on a blowdown and refill scenario, to verify the ability of numerical scheme to simulate rapid pressure decrease and phase change phenomena. The validation is performed against FLECHT-SEASET reflood experiment. showing accurate results and reduced calculation time. The implicit method offers precise solution with efficient simulation with high CFL number and has potential for further use and development in nuclear thermal hydraulic field. - COLLAPSE
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DEVELOPMENT OF AN IMPLICIT NUMERICAL METHOD FOR TWO-PHASE FLOW ANALYSIS OF PRESSURIZED WATER REACTORS
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Original Article
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DEVELOPMENT AND VERIFICATION OF CUPID-MSR FOR MOLTEN SALT NUCLEAR REACTOR FLUID DESIGN
용융염 원자로 유체 설계를 위한 CUPID-MSR 개발 및 검증
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R. Stoga, Y.J. Cho, H.Y. Yoon
StogaRafal, 조윤제, 윤한영
- CUPID-MSR is an extension of the thermal-hydraulic CFD code CUPID, with modifications for the simulation of Molten Salt Reactors (MSRs). The current …
- CUPID-MSR is an extension of the thermal-hydraulic CFD code CUPID, with modifications for the simulation of Molten Salt Reactors (MSRs). The current CUPID-MSR supports two eutectic molten salt mixtures: uranium-potassium-chloride (U-K-Cl) and uranium-sodium-magnesium-chloride (U-Na-Mg-Cl) compounds. Code verification was performed using the widely recognized De Vahl Davis benchmark problem, which features a buoyancy-driven thermal cavity. The difference from the reference solution ranges from 0.12% to 8.34% for the U-K-Cl compound, and from 1.89% to 5.95% for the U-Na-Mg-Cl compound, with minimal differences between the two results (<2.5%), confirming the accuracy of the implementation. Additionally, CUPID-MSR was also applied to a conceptual fast neutron spectrum MSR design using a horizontal cylinder-type vessel. Nine configurations were investigated, combining reactor diameters of 35, 40, and 45 cm with inlet disks containing 0, 4, or 8 openings. Configurations with 8 openings showed stable flow and the lowest local temperatures (658°C-661°C), while cases without openings exhibited flow instability and the highest local temperatures (672°C-695°C). These results confirm the successful implementation of molten salt properties into CUPID-MSR and present its reliability as a simulation tool for new MSR fluid designs. - COLLAPSE
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DEVELOPMENT AND VERIFICATION OF CUPID-MSR FOR MOLTEN SALT NUCLEAR REACTOR FLUID DESIGN
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Original Article
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APPLICATION OF ENTROPY FIX TO COMPUTATIONS OF HYPERSONIC LAMINAR AND TURBULENT BOUNDARY LAYERS ON HIFIRE-1
엔트로피 수정 기법을 이용한 HIFiRE-1 모델의 극초음속 층류 및 난류 경계층 수치해석
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J. Park, M. Jeong, S. Jee
박재현, 정민재, 지솔근
- This study presents a case study of hypersonic laminar and turbulent boundary layers on the HIFiRE-1 model, proposed as a benchmark in …
- This study presents a case study of hypersonic laminar and turbulent boundary layers on the HIFiRE-1 model, proposed as a benchmark in the 2024 High-Fidelity CFD Verification Workshop. Computations were initially performed with the Roe flux-differencing scheme, but non-physical carbuncle phenomena appeared near the cone nose. To improve numerical stability, an entropy fix was applied by modifying the eigenvalues comprising the dissipation term. The improved simulation captured key shock structures and showed good agreement with reference data including surface pressure and heat flux. The turbulent heat flux is up to four times higher than in the laminar one, highlighting the impact of the boundary layer state on the aerothermodynamics of a high-speed vehicle. - COLLAPSE
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APPLICATION OF ENTROPY FIX TO COMPUTATIONS OF HYPERSONIC LAMINAR AND TURBULENT BOUNDARY LAYERS ON HIFIRE-1
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Original Article
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A STUDY ON THE COOLING PERFORMANCE OF Z-TYPE AIR-COOLED BATTERY PACK WITH VARYING SLOPE OF MANIFOLD
Z자형 공랭식 배터리팩의 매니폴드 기울기 변화에 따른 냉각 성능에 대한 연구
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B. Jeong, J. Ko, J.H. Kim, J.Y. Kim, C. Kang
정바회, 고정훈, 김준희, 김정열, 강창우
- A specific design for the coolant passage of an air-cooled Z-type lithium-ion battery pack is introduced to enhance cooling performance. The inclined …
- A specific design for the coolant passage of an air-cooled Z-type lithium-ion battery pack is introduced to enhance cooling performance. The inclined manifold is utilized for the inlet and outlet coolant passages, and the inclinations are varied to investigate their influence on cooling efficiency and power consumption. When the inlet manifold tapers toward the end, the coolant is distributed more uniformly to the gap between the battery modules, thereby improving the uniformity of the battery temperature. However, power consumption gradually increases because the tapered manifold impedes the inflow of the coolant, resulting in a rise in the pressure difference between the inlet and outlet. As the outlet manifold expands toward the end, the cell-temperature uniformity is steadily improved by reducing the blocking effect of the coolant that flows into the outlet manifold through the gaps between cells. additionally, less power is needed to maintain a constant flow rate with the expanding manifold. - COLLAPSE
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A STUDY ON THE COOLING PERFORMANCE OF Z-TYPE AIR-COOLED BATTERY PACK WITH VARYING SLOPE OF MANIFOLD
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Original Article
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NUMERICAL STUDY ON THE VENTILATION PERFORMANCE OF GREENHOUSE ACCORDING TO ROOF VENT CONFIGURATION
비닐온실의 지붕 환기 방식에 따른 환기 성능 수치해석 연구
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S.-H. Kang, S.H. Yum
강승희, 염성현
- In the present study, the ventilation performance of two different Venlo-typed greenhouse with a roll-up typed roof and one with a rack-and-pinion …
- In the present study, the ventilation performance of two different Venlo-typed greenhouse with a roll-up typed roof and one with a rack-and-pinion typed roof is numerically investigated under hot temperature conditions. The thermal-flow fields and ventilation performance of the greenhouse are analyzed and compared by a commercial software. The results show that the roll-up roof greenhouse, despite having a slightly lower ventilation rate, offers the advantage of uniform internal cooling due to stable airflow along its streamlined roof. In contrast, the rack-and-pinion greenhouse provides a higher overall ventilation rate but creates localized high-temperature zone due to flow separation around the vents, leading to significant non-uniformity in the internal temperature distribution. - COLLAPSE
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NUMERICAL STUDY ON THE VENTILATION PERFORMANCE OF GREENHOUSE ACCORDING TO ROOF VENT CONFIGURATION
Journal Informaiton
Journal of Computational Fluids Engineering
Journal of Computational Fluids Engineering
Korean Society for Computational Fluids Engineering
한국전산유체공학회
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Tel: 82-2-701-8992 / E-mail: kscfe@kscfe.or.kr Copyright© Korean Society for Computational Fluids Engineering. Powered by APUB
Tel: 82-2-701-8992 / E-mail: kscfe@kscfe.or.kr Copyright© Korean Society for Computational Fluids Engineering. Powered by APUB