Seong-Bhin Kim
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Seong-Bhin Kim has a total of 13 co-authors. Here are the top co-authors by number of shared publications:
- Hwi-Ung Choi
Department of Refrigeration and Air-Conditioning Engineering, Chonnam National University, Yeosu 59626, Republic of Korea
7 shared publications - Kwang-Am Moon
Department of Refrigeration and Air-Conditioning Engineering, Chonnam National University, Yeosu 59626, Republic of Korea
3 shared publications - Kwang-Hwan Choi
Department of Refrigeration and Air-Conditioning Engineering, Pukyong National University, Busan 48513, Republic of Korea
3 shared publications - Aejung Yoon
Department of Mechanical Engineering, Ulsan National Institute of Science and Technology , Ulsan 44919
2 shared publications - Byeong-Hwa An
Department of Refrigeration and Air-Conditioning Engineering, Chonnam National University, Yeosu 59626, Republic of Korea
2 shared publications - Daud Mustafa Minhas
Industrial Security Lab, ZeMA—Center for Mechatronics and Automation Technology, D-66121 Saarbrücken, Germany
1 shared publication
Latest Publications
- Open Access
Numerical Analysis of Thermal Performance of Flat-Plate Solar Air–Water Heater for Simultaneous Heating of Air and Water
A solar air–water heater (SAWH) is a solar collector capable of heating air and water simultaneously. Although many studies have examined the performance and applicability of SAWHs, the effects of operating conditions, weather conditions, and design parameters on their thermal behavior remain unclear. In this study, the thermal behavior of an SAWH operating in simultaneous air-heating and water-heating mode was investigated under various conditions. A numerical model based on energy balance equations was developed and validated against experimental data. The validated model was then used to determine the effects of inlet air and water temperatures, air and water mass flow rates, weather conditions, fin height, and number of fins. The air-side and water-side thermal efficiencies ranged from −18.2% to 83.19% and from −14.58% to 98.87%, respectively, which indicates that improper operating conditions may cause heat loss. The total thermal efficiency ranged from 63.37% to 85.81%. Among the investigated parameters, the inlet fluid temperature, air mass flow rate, solar irradiance, and fin height considerably influenced thermal efficiency, whereas the effects of the other parameters were relatively limited. These findings are expected to provide valuable guidance for predicting SAWH performance and selecting appropriate operating and design conditions, thereby promoting the wider adoption and application of this type of solar collector.
Open AccessNumerical Analysis of Thermal Performance of Flat-Plate Solar Air–Water Heater for Simultaneous Heating of Air and Water
A solar air–water heater (SAWH) is a solar collector capable of heating air and water simultaneously. Although many studies have examined the performance and applicability of SAWHs, the effects of operating conditions, weather conditions, and design parameters on their thermal behavior remain unclear. In this study, the thermal behavior of an SAWH operating in simultaneous air-heating and water-heating mode was investigated under various conditions. A numerical model based on energy balance equations was developed and validated against experimental data. The validated model was then used to determine the effects of inlet air and water temperatures, air and water mass flow rates, weather conditions, fin height, and number of fins. The air-side and water-side thermal efficiencies ranged from −18.2% to 83.19% and from −14.58% to 98.87%, respectively, which indicates that improper operating conditions may cause heat loss. The total thermal efficiency ranged from 63.37% to 85.81%. Among the investigated parameters, the inlet fluid temperature, air mass flow rate, solar irradiance, and fin height considerably influenced thermal efficiency, whereas the effects of the other parameters were relatively limited. These findings are expected to provide valuable guidance for predicting SAWH performance and selecting appropriate operating and design conditions, thereby promoting the wider adoption and application of this type of solar collector.
- 1 June 2026
- Published by AIP Publishing in Physics of Fluids
- Vol. 38 (6)
Numerical study on choking onset of Hyperloop systems: Effect of blockage ratio
This study performs a numerical investigation into the choking onset of Hyperloop systems. As a pod travels through a near-vacuum tube, the bypass flow between the pod and tube walls accelerates, eventually reaching a choked state at the minimum bypass area (throat). Using a two-dimensional axisymmetric model, the choking onset—defined by the first occurrence of sonic flow at the throat—is analyzed across a blockage ratio (BR) range of 0.16–0.64. The numerical results indicate that the idealized isentropic limit underestimates the critical pod Mach number at the choking onset, with the discrepancy intensifying as BR increases. To account for this discrepancy, two effects are systematically analyzed: the upstream state change induced by the leading shock wave (LSW) ahead of the pod and the reduction in bypass area caused by boundary layer displacement on the pod and tube walls. At sufficiently low BR, the modified correlation incorporating only the LSW-induced upstream state change aligns reasonably well with the numerical results. However, the discrepancy between this LSW-only correlation and the numerical results intensifies as BR increases. Specifically, at the highest BR, the maximum deviation of −38% for the isentropic limit is reduced to +14.4% by accounting for the LSW effect and is ultimately reduced to +3.8% when the reduction in bypass area is additionally incorporated. These findings demonstrate that both effects must be considered to accurately predict the choking onset across a broad range of BR in Hyperloop systems.
- 1 June 2026
- Published by AIP Publishing in Physics of Fluids
- Vol. 38 (6)
Numerical study on choking onset of Hyperloop systems: Effect of blockage ratio
This study performs a numerical investigation into the choking onset of Hyperloop systems. As a pod travels through a near-vacuum tube, the bypass flow between the pod and tube walls accelerates, eventually reaching a choked state at the minimum bypass area (throat). Using a two-dimensional axisymmetric model, the choking onset—defined by the first occurrence of sonic flow at the throat—is analyzed across a blockage ratio (BR) range of 0.16–0.64. The numerical results indicate that the idealized isentropic limit underestimates the critical pod Mach number at the choking onset, with the discrepancy intensifying as BR increases. To account for this discrepancy, two effects are systematically analyzed: the upstream state change induced by the leading shock wave (LSW) ahead of the pod and the reduction in bypass area caused by boundary layer displacement on the pod and tube walls. At sufficiently low BR, the modified correlation incorporating only the LSW-induced upstream state change aligns reasonably well with the numerical results. However, the discrepancy between this LSW-only correlation and the numerical results intensifies as BR increases. Specifically, at the highest BR, the maximum deviation of −38% for the isentropic limit is reduced to +14.4% by accounting for the LSW effect and is ultimately reduced to +3.8% when the reduction in bypass area is additionally incorporated. These findings demonstrate that both effects must be considered to accurately predict the choking onset across a broad range of BR in Hyperloop systems.
- Open Access
Comparative Assessment of Supervised Machine Learning Models for Predicting Water Uptake in Sorption-Based Thermal Energy Storage
In this study, supervised machine learning (ML) regression models are employed to predict water uptake during the sorption process in a sorption reactor for thermal energy storage applications. Two main methods are used to study sorption storage systems: experimental studies and numerical simulations. Experimental studies involve physical testing and measurements but are often costly and time-consuming. Numerical simulations are more flexible and cost-effective, though they can require significant computational resources for large or complex systems. To address these challenges, researchers are increasingly employing various machine learning techniques, which offer strong potential for data analysis and predictive modeling. In this study, CFD-based sorption simulations are integrated with machine learning models to predict the spatiotemporal evolution of water uptake. Several ML techniques including support vector regression (SVR), Random Forest, XGBoost, CatBoost (gradient boosting decision trees), and multilayer perceptron neural networks (MLPs) are evaluated and compared. A fixed-bed reactor equipped with fins and tubes is considered within a closed adsorption thermal storage system. Numerical simulations are conducted for three different fin lengths (10 mm, 25 mm, and 35 mm) to generate a comprehensive dataset for training the ML models and capturing the complex temporal evolution of water uptake, thereby enabling predictions for unseen fin geometries. The results indicate that neural network-based models achieve superior predictive performance compared to the other methods. For water uptake training, the mean absolute error (MAE), root mean squared error (RMSE), and coefficient of determination are approximately 2.83, 4.37, and 0.91, respectively. The predicted water uptake shows close agreement with the numerical simulation results. For the prediction cases, the MAE, MSE, and values are approximately 1.13, 1.2, and 0.8, respectively. Overall, the study demonstrates that machine learning models can accurately predict water uptake beyond the training dataset, indicating strong generalization capability and significant potential for improving thermal management system design. Additionally, the proposed approach reduces simulation time and computational cost while providing an efficient and reliable framework for modeling complex sorption processes in thermal energy storage systems.Open AccessComparative Assessment of Supervised Machine Learning Models for Predicting Water Uptake in Sorption-Based Thermal Energy Storage
In this study, supervised machine learning (ML) regression models are employed to predict water uptake during the sorption process in a sorption reactor for thermal energy storage applications. Two main methods are used to study sorption storage systems: experimental studies and numerical simulations. Experimental studies involve physical testing and measurements but are often costly and time-consuming. Numerical simulations are more flexible and cost-effective, though they can require significant computational resources for large or complex systems. To address these challenges, researchers are increasingly employing various machine learning techniques, which offer strong potential for data analysis and predictive modeling. In this study, CFD-based sorption simulations are integrated with machine learning models to predict the spatiotemporal evolution of water uptake. Several ML techniques including support vector regression (SVR), Random Forest, XGBoost, CatBoost (gradient boosting decision trees), and multilayer perceptron neural networks (MLPs) are evaluated and compared. A fixed-bed reactor equipped with fins and tubes is considered within a closed adsorption thermal storage system. Numerical simulations are conducted for three different fin lengths (10 mm, 25 mm, and 35 mm) to generate a comprehensive dataset for training the ML models and capturing the complex temporal evolution of water uptake, thereby enabling predictions for unseen fin geometries. The results indicate that neural network-based models achieve superior predictive performance compared to the other methods. For water uptake training, the mean absolute error (MAE), root mean squared error (RMSE), and coefficient of determination are approximately 2.83, 4.37, and 0.91, respectively. The predicted water uptake shows close agreement with the numerical simulation results. For the prediction cases, the MAE, MSE, and values are approximately 1.13, 1.2, and 0.8, respectively. Overall, the study demonstrates that machine learning models can accurately predict water uptake beyond the training dataset, indicating strong generalization capability and significant potential for improving thermal management system design. Additionally, the proposed approach reduces simulation time and computational cost while providing an efficient and reliable framework for modeling complex sorption processes in thermal energy storage systems. - Open Access
- 26 July 2025
- Published by Elsevier in Case Studies in Thermal Engineering
- Vol. 74
Dynamic analysis of variable-refrigerant-flow system integrated with baffled indirect evaporative cooler
- 26 July 2025
- Published by Elsevier in Case Studies in Thermal Engineering
- Vol. 74
Open AccessDynamic analysis of variable-refrigerant-flow system integrated with baffled indirect evaporative cooler
- Open Access
Analysis of Heat Transfer and Fluid Flow in a Solar Air Heater with Sequentially Placed Rectangular Obstacles on the Fin Surface
A solar air heater (SAH) converts solar energy into heated air without causing environmental pollution. It features a low initial cost and easy maintenance due to its simple design. However, owing to air’s poor thermal conductivity, its thermal efficiency is relatively low compared to that of other solar systems. To improve its thermal performance, previous studies have aimed at either enlarging the heat transfer surface or increasing the convective heat transfer coefficient. In this study, a novel SAH with fins and sequentially placed obstacles on the fin surface—designed to achieve both surface extension through a finned channel and enhancement of the heat transfer coefficient via the obstacles—was investigated using computational fluid dynamics analysis. The results confirmed that the obstacles enhanced heat transfer performance by up to 2.602 times in the finned channel. However, the obstacles also caused a pressure loss. Therefore, the thermo-hydraulic performance was discussed, and it was concluded that the obstacles with a relative height of 0.12 and a relative pitch of 10 yielded the maximum THP values among the investigated conditions. Additionally, correlations for the Nusselt number and friction factor were derived and predicted the simulation values with good agreement.
Open AccessAnalysis of Heat Transfer and Fluid Flow in a Solar Air Heater with Sequentially Placed Rectangular Obstacles on the Fin Surface
A solar air heater (SAH) converts solar energy into heated air without causing environmental pollution. It features a low initial cost and easy maintenance due to its simple design. However, owing to air’s poor thermal conductivity, its thermal efficiency is relatively low compared to that of other solar systems. To improve its thermal performance, previous studies have aimed at either enlarging the heat transfer surface or increasing the convective heat transfer coefficient. In this study, a novel SAH with fins and sequentially placed obstacles on the fin surface—designed to achieve both surface extension through a finned channel and enhancement of the heat transfer coefficient via the obstacles—was investigated using computational fluid dynamics analysis. The results confirmed that the obstacles enhanced heat transfer performance by up to 2.602 times in the finned channel. However, the obstacles also caused a pressure loss. Therefore, the thermo-hydraulic performance was discussed, and it was concluded that the obstacles with a relative height of 0.12 and a relative pitch of 10 yielded the maximum THP values among the investigated conditions. Additionally, correlations for the Nusselt number and friction factor were derived and predicted the simulation values with good agreement.
- 12 February 2025
- Published by Elsevier in Thermal Science and Engineering Progress
- Vol. 59
Numerical analysis of photovoltaic–thermal air collector with fins and rectangular turbulators
- 12 February 2025
- Published by Elsevier in Thermal Science and Engineering Progress
- Vol. 59
Numerical analysis of photovoltaic–thermal air collector with fins and rectangular turbulators
- Open Access
Experimental Study on the Performance of an Air Conditioning Unit with a Baffled Indirect Evaporative Cooler
Indirect evaporative coolers (IECs) use the latent heat of water evaporation to cool air. This system has the advantage of operating at low power without a compressor and does not increase the absolute humidity of the air. However, an IEC is difficult to use on its own because its cooling capacity is limited by the theoretical constraint of the wet-bulb temperature of the ambient air. Therefore, an air conditioning unit (ACU) was integrated with an IEC and experimentally evaluated in this study. The dry and wet channels of the IEC were integrated with an ACU evaporator and a condenser, unlike previous studies where IECs were integrated solely with either an evaporator or a condenser. This reduced the cooling load on the evaporator and helped the condenser to dissipate heat to improve the performance of the existing ACU. In addition, the IEC was equipped with baffles to improve its performance. To assess the extent of the performance improvement due to integration with the IEC, comparisons were also performed under the same experimental conditions with an ACU only. The results showed that under conditions with an indoor temperature of 32 °C, integrating the IEC with the ACU increased the average cooling capacity by 13.1% and decreased the average power consumption by 8.60% during the test period, compared to using only the ACU. Consequently, the average coefficient of performance (COP) increased by 19.5% compared to using only the ACU under the same conditions.
Open AccessExperimental Study on the Performance of an Air Conditioning Unit with a Baffled Indirect Evaporative Cooler
Indirect evaporative coolers (IECs) use the latent heat of water evaporation to cool air. This system has the advantage of operating at low power without a compressor and does not increase the absolute humidity of the air. However, an IEC is difficult to use on its own because its cooling capacity is limited by the theoretical constraint of the wet-bulb temperature of the ambient air. Therefore, an air conditioning unit (ACU) was integrated with an IEC and experimentally evaluated in this study. The dry and wet channels of the IEC were integrated with an ACU evaporator and a condenser, unlike previous studies where IECs were integrated solely with either an evaporator or a condenser. This reduced the cooling load on the evaporator and helped the condenser to dissipate heat to improve the performance of the existing ACU. In addition, the IEC was equipped with baffles to improve its performance. To assess the extent of the performance improvement due to integration with the IEC, comparisons were also performed under the same experimental conditions with an ACU only. The results showed that under conditions with an indoor temperature of 32 °C, integrating the IEC with the ACU increased the average cooling capacity by 13.1% and decreased the average power consumption by 8.60% during the test period, compared to using only the ACU. Consequently, the average coefficient of performance (COP) increased by 19.5% compared to using only the ACU under the same conditions.
- Open Access
Experimental Study on the Heat Pump Performance Combined with Dual-Purpose Solar Collector
In this study, we proposed and experimentally investigated a novel solar-assisted heat pump (SAHP) system integrated with a dual-purpose solar collector (DPSC). The DPSC is a solar collector designed to produce both heated air and hot water, and the proposed configuration of the SAHP utilizes both heated air and water simultaneously to improve the performance of the heat pump. The experiment was conducted under natural weather conditions on a clear day. The performance of the proposed system was evaluated and compared to that of a conventional air-type SAHP system. The results showed that the coefficient of performance (COP) of the proposed system, which takes into account the performance of the DPSC, heat pump, and the power consumption of both the blower and pump, was 3.14. In contrast, the system COP of the SAHP operated as conventional air-type SAHP was 2.33. This finding clearly demonstrated that the proposed SAHP performed better than the traditional SAHP mode. Additionally, the results of this research are useful as fundamental data related to SAHP combined with DPSC.
Open AccessExperimental Study on the Heat Pump Performance Combined with Dual-Purpose Solar Collector
In this study, we proposed and experimentally investigated a novel solar-assisted heat pump (SAHP) system integrated with a dual-purpose solar collector (DPSC). The DPSC is a solar collector designed to produce both heated air and hot water, and the proposed configuration of the SAHP utilizes both heated air and water simultaneously to improve the performance of the heat pump. The experiment was conducted under natural weather conditions on a clear day. The performance of the proposed system was evaluated and compared to that of a conventional air-type SAHP system. The results showed that the coefficient of performance (COP) of the proposed system, which takes into account the performance of the DPSC, heat pump, and the power consumption of both the blower and pump, was 3.14. In contrast, the system COP of the SAHP operated as conventional air-type SAHP was 2.33. This finding clearly demonstrated that the proposed SAHP performed better than the traditional SAHP mode. Additionally, the results of this research are useful as fundamental data related to SAHP combined with DPSC.
- Open Access
Performance Evaluation of Air-Based Photovoltaic Thermal Collector Integrated with Dual Duct and Semicircular Turbulator in Actual Climate Conditions
An air-based photovoltaic thermal collector (PVTC) is a system that generates both electricity and heat using air flowing over a photovoltaic (PV) module. This system offers the advantage of easy maintenance; however, it suffers from lower thermal efficiency compared to other PVTCs, mostly owing to the low heat capacity of air. Thus, this study introduces a novel PVTC incorporating dual ducts and semicircular turbulators, which were experimentally evaluated under actual weather conditions in the Republic of Korea. The proposed PVTC was compared with two other types of PVTC: one is a single-duct PVTC with semicircular turbulators, and the other is a dual-duct PVTC without turbulators. The results showed that the thermal efficiency of the proposed PVTC increased by approximately 88.7% compared to the single-duct PVTC with a turbulator and by 9.3% compared to the dual-duct PVTC without a turbulator. The electrical efficiency showed a slight decrease of about 7.2% compared to the single-duct PVTC but an increase of 1.4% compared to the dual-duct PVTC without a turbulator. Overall, the total efficiency of the proposed PVTC increased by 54.2% and 7.7% compared to the single-duct PVTC and the dual-duct PVTC without a turbulator, respectively. These experimental results demonstrate that attaching dual ducts and semicircular turbulators to an existing PVTC increases the daily thermal energy output, which ultimately enhances the total daily energy output.
Open AccessPerformance Evaluation of Air-Based Photovoltaic Thermal Collector Integrated with Dual Duct and Semicircular Turbulator in Actual Climate Conditions
An air-based photovoltaic thermal collector (PVTC) is a system that generates both electricity and heat using air flowing over a photovoltaic (PV) module. This system offers the advantage of easy maintenance; however, it suffers from lower thermal efficiency compared to other PVTCs, mostly owing to the low heat capacity of air. Thus, this study introduces a novel PVTC incorporating dual ducts and semicircular turbulators, which were experimentally evaluated under actual weather conditions in the Republic of Korea. The proposed PVTC was compared with two other types of PVTC: one is a single-duct PVTC with semicircular turbulators, and the other is a dual-duct PVTC without turbulators. The results showed that the thermal efficiency of the proposed PVTC increased by approximately 88.7% compared to the single-duct PVTC with a turbulator and by 9.3% compared to the dual-duct PVTC without a turbulator. The electrical efficiency showed a slight decrease of about 7.2% compared to the single-duct PVTC but an increase of 1.4% compared to the dual-duct PVTC without a turbulator. Overall, the total efficiency of the proposed PVTC increased by 54.2% and 7.7% compared to the single-duct PVTC and the dual-duct PVTC without a turbulator, respectively. These experimental results demonstrate that attaching dual ducts and semicircular turbulators to an existing PVTC increases the daily thermal energy output, which ultimately enhances the total daily energy output.