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Prof. Man-Hoe Kim
School of Mechanical Engineering & IEDT, Kyungpook National University

Basic Info


Research Keywords & Expertise

0 Thermodynamics
0 Turbomachinery
0 HVAC&R
0 Energy system analysis, modelling and optimization
0 Thermal Systems

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Heat exchanger and heat transfer enhancement
alternative refrigerants

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Short Biography

Dr. Kim is a professor of School of Mechanical Engineering and a Director of Institute of Engineering Design and Technology, Kyungpook National University (KNU). He received his Ph.D. degree in mechanical engineering from the KAIST, South Korea in 1988. Prior to join in KNU in 2012, he worked for Samsung Electronics Co. for 15 years and worked at KAIST for 10 years as a Professor of Practice. His main research interests are in the areas of heat exchanger and heat transfer enhancement, residential and mobile air-conditioning applications, alternative refrigerant systems, renewable energy, thermal systems, CFD, Turbomachinery.

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Journal article
Published: 27 August 2021 in Energy
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A new cycle layout for the supercritical carbon dioxide with its better integration capabilities with heat sources for increased temperature difference across the receiver has been proposed and analyzed in the current study. Design point analysis of the proposed cycle layout and the available cycle layouts in literature, i.e., regenerative, recompression, intercooling, and partial cooling cycles, have been performed and compared. Moreover, the effect of turbine inlet temperature, compressor's inlet pressure, and compressor inlet temperature on the cycle's efficiency, specific work, and integration capabilities with heat source have been studied for all the cycle layouts, including the proposed cycle layout. Results suggest that the proposed cycle's configuration exhibits better integration capabilities than other cycle layouts studied in this work contributing to cost-effective power generation. The cycle's efficiency for the current cycle is comparable with the intercooling cycle, where the specific work value for the proposed process is found maximum among all the cycles. Further, the UA values for the proposed cycle are found up to 33% smaller than the intercooling cycle.

ACS Style

Muhammad Saeed; Man-Hoe Kim. A newly proposed supercritical carbon dioxide Brayton cycle configuration to enhance energy sources integration capability. Energy 2021, 121868 .

AMA Style

Muhammad Saeed, Man-Hoe Kim. A newly proposed supercritical carbon dioxide Brayton cycle configuration to enhance energy sources integration capability. Energy. 2021; ():121868.

Chicago/Turabian Style

Muhammad Saeed; Man-Hoe Kim. 2021. "A newly proposed supercritical carbon dioxide Brayton cycle configuration to enhance energy sources integration capability." Energy , no. : 121868.

Journal article
Published: 25 August 2021 in Energy
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This work presents an in-depth design analysis of full-scale airborne wind energy systems. The prime focus is to quantify the impact of an airfoil-based shell carrying a 3-bladed rotor tailored to airborne needs. A high-fidelity numerical approach is used to gain insights into the design’s performance by solving the numerical model of the resulting system. Three-dimensional simulations are carried out for a range of wind speeds and tip speed ratios to evaluate the aerodynamic behavior of the shell rotor by lifting the complete shell rotor assembly at elevated heights. The sensitiveness of the performance is rigorously analyzed in terms of the power coefficient(Cp,s), thrust coefficient, blockage effect, swallowed mass flow and bound circulation. An important finding highlights that the shell configuration is more efficient under optimal flow conditions in augmenting the power output. Besides, the augmented effects of the shell significantly contribute to the resulting Cp,s to outperform the Betz limit. Meanwhile, the net extracted power of the proposed design is 66% higher than that of the bare rotor. Finally, the simulation results suggest that the shell rotor operating close to the higher tip speed ratios behaves quite similar to that of the bare rotor configuration.

ACS Style

Qazi Shahzad Ali; Man-Hoe Kim. Quantifying Impacts of Shell Augmentation on Power Output of Airborne Wind Energy System at Elevated Heights. Energy 2021, 121839 .

AMA Style

Qazi Shahzad Ali, Man-Hoe Kim. Quantifying Impacts of Shell Augmentation on Power Output of Airborne Wind Energy System at Elevated Heights. Energy. 2021; ():121839.

Chicago/Turabian Style

Qazi Shahzad Ali; Man-Hoe Kim. 2021. "Quantifying Impacts of Shell Augmentation on Power Output of Airborne Wind Energy System at Elevated Heights." Energy , no. : 121839.

Journal article
Published: 15 June 2021 in International Journal of Heat and Mass Transfer
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Minichannel heat sinks are widely adopted heat dissipation solutions from miniaturized heat flux generating components, such as microprocessors. This paper presents further enhancements in the thermal and hydraulic performance of a minichannel heat sink by employing supercritical carbon dioxide (sCO2) as a coolant. In this study, thermal and hydraulic performance of CO2-cooled minichannel heat sink at three inlet pressures (Pin,CO2) (i.e., 8.0, 10 and 12 MPa)and inlet temperatures (Tin,CO2) ranging between 30∘C−60∘C is compared with a water-cooled minichannel heat sink at inlet conditions (0.1 MPa,30 °C−38 °C). To investigate the performance of the minichannel heat sinks, a conjugate heat transfer model is solved in a commercial code ANSYS-CFX. Whereas the variations in thermo-physical properties of supercritical carbon dioxide (sCO2) are incorporated in ANSYS-CFX through a real gas property (RGP) table. The results reveal a maximum enhancement of 42.13% in average heat transfer coefficient (h¯) for minichannel heat sink using CO2 as a coolant at inlet conditions of 8.0 MPa and34∘C. Similarly, a pressure drop reduction of 55.79% is computed for CO2 as a coolant at corresponding inlet conditions as compared to water-cooled minichannel heat sink. Moreover, the results suggest that replacing water with CO2 as a coolant at higher inlet pressures (Pin,CO2) i.e., 10 MPa and 12 MPacan further reduce pressure drops in the minichannel heat sink by 60.65% and 62.41%, respectively. Apart from the lower base temperatures, performance evaluation criteria (PEC) suggests that the overall performance of the minichannel heat sink using CO2 at 8.0 MPa is roughly enhanced by 2 times as compared to water-cooled minichannel heat sink.

ACS Style

Ahmad Ali Awais; Muhammad Saeed; Man-Hoe Kim. Performance enhancement in minichannel heat sinks using supercritical carbon dioxide (sCO2) as a coolant. International Journal of Heat and Mass Transfer 2021, 177, 121539 .

AMA Style

Ahmad Ali Awais, Muhammad Saeed, Man-Hoe Kim. Performance enhancement in minichannel heat sinks using supercritical carbon dioxide (sCO2) as a coolant. International Journal of Heat and Mass Transfer. 2021; 177 ():121539.

Chicago/Turabian Style

Ahmad Ali Awais; Muhammad Saeed; Man-Hoe Kim. 2021. "Performance enhancement in minichannel heat sinks using supercritical carbon dioxide (sCO2) as a coolant." International Journal of Heat and Mass Transfer 177, no. : 121539.

Journal article
Published: 06 June 2021 in Machines
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This paper presents the two-phase condensation heat transfer and pressure drop characteristics of R-513A as an alternative refrigerant to R-134a in a 9.52-mm OD horizontal microfin copper tube. The test facility had a straight, horizontal test section with an active length of 2.0 m and was cooled by cold water circulated in a surrounding annular space. The annular-side heat transfer coefficients were obtained using the Wilson plot method. The average heat transfer coefficient and pressure drop data are presented at the condensation temperature of 35 °C in the range of 100–440 kg·m−2·s−1 mass flux. The test data of R-513A are compared with those of R-134a, R-1234yf, and R-1234ze(E). The average condensation heat transfer coefficients of the R-513A and R-1234ze(E) refrigerants were similar to R-134a at the lower mass flux (100~150 kg·m−2·s−1), while they were up to 10% higher than R-134a as the mass flux increased. The pressure drop of R-513A was similar to R-1234yf and 10% lower than that of R-134a at the higher mass flux. The R-1234ze(E) pressure drops were 20 % higher compared to those of R-134a at the higher mass flux.

ACS Style

Andreas Karageorgis; George Hinopoulos; Man-Hoe Kim. A Comparative Study on the Condensation Heat Transfer of R-513A as an Alternative to R-134a. Machines 2021, 9, 114 .

AMA Style

Andreas Karageorgis, George Hinopoulos, Man-Hoe Kim. A Comparative Study on the Condensation Heat Transfer of R-513A as an Alternative to R-134a. Machines. 2021; 9 (6):114.

Chicago/Turabian Style

Andreas Karageorgis; George Hinopoulos; Man-Hoe Kim. 2021. "A Comparative Study on the Condensation Heat Transfer of R-513A as an Alternative to R-134a." Machines 9, no. 6: 114.

Journal article
Published: 09 May 2021 in International Journal of Refrigeration
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Refrigerant/lubricant miscibility plays an important role in the overall thermal performance and reliability of refrigeration and air-conditioning systems. R452A is considred a viable replacement of R404A refrigerant due to its comparible thermophysical properties and low global warming potential. In this paper, the miscibility of a polyol ester based oil SW32 is experimentally investigated with R404A and R452A by varying the oil mass fraction from 5% to 70% over the temperature range of 243.15K to 313.15K. The results revealed R452A is completely miscible with SW32 oil up to 30% oil mass fraction over the whole temperature range considered in the study followed by R404A which showed complete miscibility up to 20% oil mass fraction. Liquid phase separation showed the presence of three different types of immisicibility present for both refrigerant at higher oil mass fractions. Moreover, the low-global warming potential alternative, R452A demonstrated an 18% higher miscibility region with SW32 oil compared to R404A.

ACS Style

Arslan Saleem; Man-Hoe Kim. Miscibility analysis of polyol-ester based oil SW32 with R404A and low-GWP refrigerant R452A. International Journal of Refrigeration 2021, 129, 22 -31.

AMA Style

Arslan Saleem, Man-Hoe Kim. Miscibility analysis of polyol-ester based oil SW32 with R404A and low-GWP refrigerant R452A. International Journal of Refrigeration. 2021; 129 ():22-31.

Chicago/Turabian Style

Arslan Saleem; Man-Hoe Kim. 2021. "Miscibility analysis of polyol-ester based oil SW32 with R404A and low-GWP refrigerant R452A." International Journal of Refrigeration 129, no. : 22-31.

Journal article
Published: 06 May 2021 in International Journal of Heat and Mass Transfer
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Multirow finned tube heat exchangers have been extensively used as an outdoor unit in heat pump applications. Several factors, including nonuniform airflow distribution, refrigerant circuitry arrangement, fin and tube configurations, and operating conditions, have a significant influence on its thermohydraulic performance. For accurate outdoor unit heat exchanger modeling and analysis, developing a robust and experimentally validated numerical model reflecting the influence of realistic nonuniform airflow and refrigerant distribution is necessary. This paper presents a general-purpose numerical model, implemented in MATLAB, for a multirow finned tube heat exchanger using a tube-by-tube modeling approach based on the log mean enthalpy difference method. State-of-the-art heat transfer and pressure drop correlations are used for each refrigerant-side's flow regime and airside fin configuration. An alternative iteration loop is also incorporated to solve the complex circuitry of the heat exchanger under wet conditions. Simulation results of the current model yield consistent and more real heat transfer, pressure drop, and temperature contours using nonuniform airflow velocity profiles than those of the simplified models that assumed uniform airflow. Therefore, higher accuracy of the performance evaluation for complex refrigerant circuitry was achieved. Furthermore, current model is able to identify the exit vapor quality that allows proper selection of tubes and mass flow rates to avoid unnecessary superheat or sub cooling. The model is also validated with available experimental data, and the maximum error is within ±10.0%.

ACS Style

Shehryar Ishaque; Man-Hoe Kim. Numerical modeling of an outdoor unit heat exchanger for residential heat pump systems with nonuniform airflow and refrigerant distribution. International Journal of Heat and Mass Transfer 2021, 175, 121323 .

AMA Style

Shehryar Ishaque, Man-Hoe Kim. Numerical modeling of an outdoor unit heat exchanger for residential heat pump systems with nonuniform airflow and refrigerant distribution. International Journal of Heat and Mass Transfer. 2021; 175 ():121323.

Chicago/Turabian Style

Shehryar Ishaque; Man-Hoe Kim. 2021. "Numerical modeling of an outdoor unit heat exchanger for residential heat pump systems with nonuniform airflow and refrigerant distribution." International Journal of Heat and Mass Transfer 175, no. : 121323.

Journal article
Published: 06 May 2021 in Energy
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The airborne wind turbine (AWT) offers the opportunity to be installed in challenging heights. For this purpose, the present study focuses on the aerodynamic design of an airborne rotor lifted to high altitude from the viewpoint of airborne technology. The rotor blade is modeled by imposing the elevated wind dataset while the outer shape is comprised of multi-profiles of thick airfoils. Numerical approaches of the BEM and RANS-CFD are employed for insight into performance analysis. The extracted results of the CFD data agreed well with the empirical computations. The induced effect of the diffuser on the rotor is demonstrated through an auxiliary shell structure. A range of 3D simulations varying the airloads are conducted to investigate the on-design and off-design behavior of the rotor. The power coefficient (Cp), effective forces and mass amplification are computed and discussed in terms of performance indicators. The design analysis reveals the significance of the chosen design specification to an operational height of 400 m. The noticeable finding confirms that the optimal Cp of the resulting rotor always occurs at rated conditions and equally valid for both configurations. Additionally, a power gain of 21.3% is obtained from the rotor equipped with the diffuser geometry.

ACS Style

Qazi Shahzad Ali; Man-Hoe Kim. Design and performance analysis of an airborne wind turbine for high-altitude energy harvesting. Energy 2021, 230, 120829 .

AMA Style

Qazi Shahzad Ali, Man-Hoe Kim. Design and performance analysis of an airborne wind turbine for high-altitude energy harvesting. Energy. 2021; 230 ():120829.

Chicago/Turabian Style

Qazi Shahzad Ali; Man-Hoe Kim. 2021. "Design and performance analysis of an airborne wind turbine for high-altitude energy harvesting." Energy 230, no. : 120829.

Journal article
Published: 28 April 2021 in Machines
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This study focuses on the thermodynamic performance analysis of the solar organic Rankine cycle (SORC) that uses solar radiation over a moderate temperature range. A compound parabolic collector (CPC) was adjusted to collect solar radiation because of its long-lasting nature and featured low concentration ratios, which are favorable for moderate temperature applications. A thermal storage tank was fixed to preserve the solar energy and ensure the system’s continuous performance during unfavorable weather. However, water was used as the heat transfer fluid and R245fa was used as the working fluid in this system. The performance in both the hottest and coldest months was analyzed using the average hourly profile in MATLAB using weather data from Riyadh, Saudi Arabia. Variations in the tank temperature during the charging and discharging modes were found. The hourly based thermal efficiency and net power output for both configurations were also compared. The results show that at 17:00, when the cycle was about to shut down, the thermal efficiency was 12.79% and the network output was 16 kW in July, whereas in January, the efficiency was ~12.80% and the net power output was 15.54 kW.

ACS Style

Nasser Almefreji; Babras Khan; Man-Hoe Kim. Thermodynamic Performance Analysis of Solar Based Organic Rankine Cycle Coupled with Thermal Storage for a Semi-Arid Climate. Machines 2021, 9, 88 .

AMA Style

Nasser Almefreji, Babras Khan, Man-Hoe Kim. Thermodynamic Performance Analysis of Solar Based Organic Rankine Cycle Coupled with Thermal Storage for a Semi-Arid Climate. Machines. 2021; 9 (5):88.

Chicago/Turabian Style

Nasser Almefreji; Babras Khan; Man-Hoe Kim. 2021. "Thermodynamic Performance Analysis of Solar Based Organic Rankine Cycle Coupled with Thermal Storage for a Semi-Arid Climate." Machines 9, no. 5: 88.

Journal article
Published: 22 April 2021 in Applied Sciences
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This paper presents the parameterization and optimization of two well-known airfoils. The aerodynamic shape optimization investigation includes the subsonic (NREL S-821) and transonic airfoils (RAE-2822). The class shape transformation is employed for parametrization while the genetic algorithm is used for optimization purposes. The absolute scheme of the optimization process is carried out for the minimization of the drag coefficient and maximization of lift to drag ratio. In-house MATLAB code is incorporated with a genetic algorithm to calculate the drag coefficient and lift to drag ratio of the resulting optimized airfoil. The panel method is utilized in genetic algorithm optimization code to calculate pressure distribution, lift coefficient, and lift to drag ratio for optimized airfoil shapes and validates with XFOIL and NREL experimental data. Furthermore, CFD analysis is conducted for both the original (NREL S-821) and optimized airfoil obtained. The present method shows that the optimized airfoil achieved an improvement in lift to drag ratio by 7.4% and 15.9% of S-821 and RAE-2822 airfoil, respectively, by the panel technique method and provides high design desirable stability parameters. These features significantly improve the overall aerodynamic performance of the newly optimized airfoils. Finally, the improved aerodynamics results are reported for the design of turbulence modeling and NREL phase II, Phase III, and Phase VI HAWT blades.

ACS Style

Tausif Akram; Man-Hoe Kim. CFD Analysis and Shape Optimization of Airfoils Using Class Shape Transformation and Genetic Algorithm—Part I. Applied Sciences 2021, 11, 3791 .

AMA Style

Tausif Akram, Man-Hoe Kim. CFD Analysis and Shape Optimization of Airfoils Using Class Shape Transformation and Genetic Algorithm—Part I. Applied Sciences. 2021; 11 (9):3791.

Chicago/Turabian Style

Tausif Akram; Man-Hoe Kim. 2021. "CFD Analysis and Shape Optimization of Airfoils Using Class Shape Transformation and Genetic Algorithm—Part I." Applied Sciences 11, no. 9: 3791.

Review
Published: 10 March 2021 in Energies
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Sediment and cavitation erosion of the hydroelectric power turbine components are the fundamental problems in the rivers of Himalayas and Andes. In the present work, the latest research conducted in both the fields by various investigators and researchers are discussed and critically analyzed at different turbine components. Analysis shows that both types of erosion depends on flow characteristics, surface, and erodent material properties. Design optimization tools, coalesced effect (CE) of sediment and cavitation erosion and well conducted experiments will yield results that are beneficial for erosion identification and reduction. Although some researchers have done experimental work on the coalesced effect (CE) of sediment and cavitation erosion, very limited Computational Fluid Dynamics (CFD) work is available in literature. The present research work will be beneficial for practitioners and researchers in the future to address the erosion problem successfully.

ACS Style

Adnan Noon; Man-Hoe Kim. Sediment and Cavitation Erosion in Francis Turbines—Review of Latest Experimental and Numerical Techniques. Energies 2021, 14, 1516 .

AMA Style

Adnan Noon, Man-Hoe Kim. Sediment and Cavitation Erosion in Francis Turbines—Review of Latest Experimental and Numerical Techniques. Energies. 2021; 14 (6):1516.

Chicago/Turabian Style

Adnan Noon; Man-Hoe Kim. 2021. "Sediment and Cavitation Erosion in Francis Turbines—Review of Latest Experimental and Numerical Techniques." Energies 14, no. 6: 1516.

Journal article
Published: 03 March 2021 in Applied Sciences
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Sustainability has become one of the most significant considerations in everyday work, including energy production. The fast-growing trend of wind energy around the world has increased the demand for efficient and optimized airfoils, which has paved the way for energy harvesting systems. The present manuscript proposes an aerodynamically optimized design of the well-known existing NREL S809 airfoil for performance enhancement of the blade design for wind turbines. An integrated code, based on a genetic algorithm, is developed to optimize the asymmetric NREL S809 airfoil by class shape transformation (CST) and the parametric section (PARSEC) parameterization method, analyzing its aerodynamic properties and maximizing the lift of the airfoil. The in-house MATLAB code is further incorporated with XFOIL to calculate the coefficient of lift, coefficient of drag and lift-to-drag ratio at angles of attack of 0° and 6.2° by the panel technique and validated with National Renewable Energy Laboratory (NREL) experimental results provided by The Ohio State University (OSU). On the other hand, steady-state CFD analysis is performed on an optimized S809 airfoil using the Reynolds-averaged Navier–Stokes (RANS) equation with the K–ω shear stress transport (SST) turbulent model and compared with the experimental data. The present method shows that the optimized airfoil by CST is predicted, with an increment of 11.8% and 9.6% for the lift coefficient and lift-to-drag ratio, respectively, and desirable stability parameters obtained for the design of the wind turbine blades. These characteristics significantly improve the overall aerodynamic performance of new optimized airfoils. Finally, the aerodynamically improved results are reported for the design of the NREL Phase II, Phase III and Phase VI HAWT blades.

ACS Style

Tausif Akram; Man-Hoe Kim. Aerodynamic Shape Optimization of NREL S809 Airfoil for Wind Turbine Blades Using Reynolds-Averaged Navier Stokes Model—Part II. Applied Sciences 2021, 11, 2211 .

AMA Style

Tausif Akram, Man-Hoe Kim. Aerodynamic Shape Optimization of NREL S809 Airfoil for Wind Turbine Blades Using Reynolds-Averaged Navier Stokes Model—Part II. Applied Sciences. 2021; 11 (5):2211.

Chicago/Turabian Style

Tausif Akram; Man-Hoe Kim. 2021. "Aerodynamic Shape Optimization of NREL S809 Airfoil for Wind Turbine Blades Using Reynolds-Averaged Navier Stokes Model—Part II." Applied Sciences 11, no. 5: 2211.

Journal article
Published: 28 February 2021 in Transctions of the Korean Hydrogen and New Energy Society
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ACS Style

Man-Hoe Kim. Heat Transfer Coefficients of Concentric Annuli for Testing Heat Transfer Characteristics of Alternative Refrigerants in Tubes. Transctions of the Korean Hydrogen and New Energy Society 2021, 32, 63 -67.

AMA Style

Man-Hoe Kim. Heat Transfer Coefficients of Concentric Annuli for Testing Heat Transfer Characteristics of Alternative Refrigerants in Tubes. Transctions of the Korean Hydrogen and New Energy Society. 2021; 32 (1):63-67.

Chicago/Turabian Style

Man-Hoe Kim. 2021. "Heat Transfer Coefficients of Concentric Annuli for Testing Heat Transfer Characteristics of Alternative Refrigerants in Tubes." Transctions of the Korean Hydrogen and New Energy Society 32, no. 1: 63-67.

Journal article
Published: 09 February 2021 in Energy Conversion and Management
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This paper investigates the thermal performance of the recompression supercritical carbon dioxide power cycle integrated with a direct air-cooled heat exchanger. The desirable attributes for economical concentrated solar power plants are their integration ability with thermal energy storage and to accommodate dry cooling. The expressively influencing parameters such as compressor inlet temperature, pressure, and split mass fraction have been investigated for cycle maximum efficiency under arid climatic conditions. The cooling process of supercritical carbon dioxide, unlike steam condensation, is sensible heat transfer with the non-linear variation of thermophysical properties. Effective, efficient, and affordable heat exchanger technology is crucial for the deployment of supercritical carbon dioxide Brayton power cycles in concentrated solar power plants. A MATLAB code has been developed for an air-cooled heat exchanger with multi-pass sub heat exchanger approach to overcome the inevitable temperature variations at the extreme end of the gas cooler. A two dimensional discretization methodology is used to model the heat exchanger to accommodate the rapidly varying isobaric heat capacity in the critical temperature region. The heat transfer and pressure drop performance are calculated using empirical correlations for the Nusselt number and friction factor for each sub-heat exchanger. With the increased contact time of cooling and process fluid, the desired gas cooler outlet temperature of 33.5 °C is achieved by rejecting 823.76 kW, 359.5 kW, and 219.46 kW amount of heat from each sub-heat exchanger, respectively. The results of this work are of significance for the design of the air-cooled heat exchanger for the supercritical carbon dioxide power generation system.

ACS Style

Saboora Khatoon; Shehryar Ishaque; Man-Hoe Kim. Modeling and analysis of air-cooled heat exchanger integrated with supercritical carbon dioxide recompression Brayton cycle. Energy Conversion and Management 2021, 232, 113895 .

AMA Style

Saboora Khatoon, Shehryar Ishaque, Man-Hoe Kim. Modeling and analysis of air-cooled heat exchanger integrated with supercritical carbon dioxide recompression Brayton cycle. Energy Conversion and Management. 2021; 232 ():113895.

Chicago/Turabian Style

Saboora Khatoon; Shehryar Ishaque; Man-Hoe Kim. 2021. "Modeling and analysis of air-cooled heat exchanger integrated with supercritical carbon dioxide recompression Brayton cycle." Energy Conversion and Management 232, no. : 113895.

Review
Published: 21 January 2021 in Materials
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Centrifugal pumps are being widely used in various industries for moving fluids that carry solids through pipelines where the need of head and flow rate is not high. Slurry erosion and cavitation are an extremely complex and not yet fully understood phenomenon that occur in centrifugal pumps; however, these undesirable phenomena can be reduced to a certain extent. Appropriate design and development of experiments is required to reasonably predict slurry erosion and cavitation. However, CFD methodology complements analytical solutions and experiments whenever testing of equipment has limitations. The current paper highlights the various slurry erosion and cavitation reduction techniques utilized by different researchers. Economic analysis conducted for a case study relevant to centrifugal pump (CP) usage in Pakistan shows that an 8% enhancement in pump efficiency can reduce the life cycle cost to about 17.6%, which could save up to USD 4281 for a single pump annually in Pakistan.

ACS Style

Adnan Noon; Absaar Jabbar; Hasan Koten; Man-Hoe Kim; Hafiz Ahmed; Umair Mueed; Ahmad Shoukat; Bilal Anwar. Strive to Reduce Slurry Erosion and Cavitation in Pumps Through Flow Modifications, Design Optimization and Some Other Techniques: Long Term Impact on Process Industry. Materials 2021, 14, 521 .

AMA Style

Adnan Noon, Absaar Jabbar, Hasan Koten, Man-Hoe Kim, Hafiz Ahmed, Umair Mueed, Ahmad Shoukat, Bilal Anwar. Strive to Reduce Slurry Erosion and Cavitation in Pumps Through Flow Modifications, Design Optimization and Some Other Techniques: Long Term Impact on Process Industry. Materials. 2021; 14 (3):521.

Chicago/Turabian Style

Adnan Noon; Absaar Jabbar; Hasan Koten; Man-Hoe Kim; Hafiz Ahmed; Umair Mueed; Ahmad Shoukat; Bilal Anwar. 2021. "Strive to Reduce Slurry Erosion and Cavitation in Pumps Through Flow Modifications, Design Optimization and Some Other Techniques: Long Term Impact on Process Industry." Materials 14, no. 3: 521.

Journal article
Published: 13 January 2021 in Energies
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This study focuses on the thermal performance analysis of an organic Rankine cycle powered vapor compression refrigeration cycle for a set of working fluids for each cycle, also known as a dual fluid system. Both cycles are coupled using a common shaft to maintain a constant transmission ratio of one. Eight working fluids have been studied for the vapor compression refrigeration cycle, and a total of sixty-four combinations of working fluids have been analyzed for the dual fluid combined cycle system. The analysis has been performed to achieve a temperature of −16 °C for a set of condenser temperatures 34 °C, 36 °C, 38 °C, and 40 °C. For the desired temperature in the refrigeration cycle, the required work input, mass flow rate, and heat input for the organic Rankine cycle were determined systematically. Based on the manifestation of performance criteria, three working fluids (R123, R134a, and R245fa) were chosen for the refrigeration cycle and two (Propane and R245fa) were picked for the organic Rankine cycle. Further, a combination of R123 in the refrigeration cycle with propane in the Rankine cycle was scrutinized for their highest efficiency value of 16.48% with the corresponding highest coefficient of performance value of 2.85 at 40 °C.

ACS Style

Saboora Khatoon; Nasser Mohammed A. Almefreji; Man-Hoe Kim. Thermodynamic Study of a Combined Power and Refrigeration System for Low-Grade Heat Energy Source. Energies 2021, 14, 410 .

AMA Style

Saboora Khatoon, Nasser Mohammed A. Almefreji, Man-Hoe Kim. Thermodynamic Study of a Combined Power and Refrigeration System for Low-Grade Heat Energy Source. Energies. 2021; 14 (2):410.

Chicago/Turabian Style

Saboora Khatoon; Nasser Mohammed A. Almefreji; Man-Hoe Kim. 2021. "Thermodynamic Study of a Combined Power and Refrigeration System for Low-Grade Heat Energy Source." Energies 14, no. 2: 410.

Journal article
Published: 13 May 2020 in Energy
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The present manuscript proposes an aerodynamically optimized airfoil-based-shell for performance enhancement of the buoyant airborne turbine system. An integrated code, based on a genetic algorithm, is developed to parametrize the asymmetric airfoil NACA-9415, analyse its aerodynamics and optimize the lift of the airfoil. The 3D steady-state analysis is performed on the optimized shell geometry with NREL-IV rotor using Reynolds Averaged Navier-Stokes (RANS) equation along with k−ωSST turbulence model. The performance of the airborne wind turbine with the optimized shell configuration is assessed in terms of aerodynamic coefficients including shell thrust coefficient, shell back pressure coefficient, turbine power coefficient and power augmentation ratio. The comparison of wind turbine performance with optimized and original NACA-9415 shell configuration demonstrates that shell optimization results in a maximum power coefficient of 1.25 and power augmentation ratio of 2.1 compared to the Betz limit.

ACS Style

Arslan Saleem; Man-Hoe Kim. Aerodynamic performance optimization of an airfoil-based airborne wind turbine using genetic algorithm. Energy 2020, 203, 117841 .

AMA Style

Arslan Saleem, Man-Hoe Kim. Aerodynamic performance optimization of an airfoil-based airborne wind turbine using genetic algorithm. Energy. 2020; 203 ():117841.

Chicago/Turabian Style

Arslan Saleem; Man-Hoe Kim. 2020. "Aerodynamic performance optimization of an airfoil-based airborne wind turbine using genetic algorithm." Energy 203, no. : 117841.

Journal article
Published: 01 April 2020 in Energy Conversion and Management
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ACS Style

Qazi Shahzad Ali; Man-Hoe Kim. Unsteady aerodynamic performance analysis of an airborne wind turbine under load varying conditions at high altitude. Energy Conversion and Management 2020, 210, 1 .

AMA Style

Qazi Shahzad Ali, Man-Hoe Kim. Unsteady aerodynamic performance analysis of an airborne wind turbine under load varying conditions at high altitude. Energy Conversion and Management. 2020; 210 ():1.

Chicago/Turabian Style

Qazi Shahzad Ali; Man-Hoe Kim. 2020. "Unsteady aerodynamic performance analysis of an airborne wind turbine under load varying conditions at high altitude." Energy Conversion and Management 210, no. : 1.

Review article
Published: 03 March 2020 in Applied Energy
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Nanofluid is an innovative class of nanotechnology-based thermal fluids and has been proven to improve the energy conversion process efficiency significantly. Thermal conductivity of the nanofluids, the fundamental thermophysical property determining their performance, is a subject of extensive controversies over the years and thereby incites the fundamental doubts in the commercial application of these innovative thermal fluids. A possible justification of these inconsistencies is the lack of comprehensive data over a wide range of sensitive parameters characterizing the effective thermal conductivity of the nanofluids including particle morphology (size and shape) and concentration, fluid temperature, particle and hosting fluid properties, measurement and stability techniques. Particle size, the most discernible feature differentiating nanofluids from micrometre-sized suspensions, contributes not only in ensuring dispersion stability but predominantly influences their heat transport characteristics. Therefore the study is aimed at presenting a critical review of all the experimental, theoretical and numerical investigations on the particle-size-dependent effective thermal conductivity of the nanofluids to comprehend the influence of nanoparticle size variation on the thermal performance of the nanofluids in diverse nanofluid combinations and operational conditions. The study also incorporates a systematic comparison of the experimental results to explicate anomalies in reported results and the mutual impact of imperative parameters on the particle-size-dependent thermal conductivity of the nanofluids.

ACS Style

Tehmina Ambreen; Man-Hoe Kim. Influence of particle size on the effective thermal conductivity of nanofluids: A critical review. Applied Energy 2020, 264, 114684 .

AMA Style

Tehmina Ambreen, Man-Hoe Kim. Influence of particle size on the effective thermal conductivity of nanofluids: A critical review. Applied Energy. 2020; 264 ():114684.

Chicago/Turabian Style

Tehmina Ambreen; Man-Hoe Kim. 2020. "Influence of particle size on the effective thermal conductivity of nanofluids: A critical review." Applied Energy 264, no. : 114684.

Journal article
Published: 25 February 2020 in Applied Thermal Engineering
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Inefficient distributor and collector header design in a minichannel heat sink causes flow maldistribution which can severely degrade the thermal and hydraulic performance of the heat sink. This paper presents an experimental and numerical investigation on the thermohydraulic performance of minichannel heat sinks with two different header geometries using nanofluids. A series of tests are conducted on a minichannel heat sink with optimized and conventional header geometries by using (Al2O3-H2O) nanofluids and distilled water as coolants. The effects of header geometry, nanoparticle concentration, and coolant flow rate on the overall heat transfer coefficient, heat transfer enhancement, thermal resistance, and base temperature are investigated. The experimental and numerical results exhibited good agreement, indicating that the thermohydraulic performance of the heat sink with the optimized header geometry is superior to that with the conventional header geometry. The minichannel heat sink with the optimized header geometry exhibited 17% higher overall heat transfer coefficient and 43% reduction in pressure drop while achieving lower values for base temperature and thermal resistance for each employed flow rate and volumetric concentration of nanoparticles. Furthermore, the performance evaluation criteria (PEC) indicated a 41% improvement in hydraulic performance while using minichannel heat sink with optimized header geometry compared to that with the conventional header geometry.

ACS Style

Ahmad Ali Awais; Man-Hoe Kim. Experimental and numerical study on the performance of a minichannel heat sink with different header geometries using nanofluids. Applied Thermal Engineering 2020, 171, 115125 .

AMA Style

Ahmad Ali Awais, Man-Hoe Kim. Experimental and numerical study on the performance of a minichannel heat sink with different header geometries using nanofluids. Applied Thermal Engineering. 2020; 171 ():115125.

Chicago/Turabian Style

Ahmad Ali Awais; Man-Hoe Kim. 2020. "Experimental and numerical study on the performance of a minichannel heat sink with different header geometries using nanofluids." Applied Thermal Engineering 171, no. : 115125.

Journal article
Published: 07 February 2020 in Applied Sciences
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This paper presents performance analysis results on supercritical carbon dioxide ( s C O 2 ) re-compression Brayton cycle. Monthly exergy destruction analysis was conducted to find the effects of different ambient and water temperatures on the performance of the system. The results reveal that the gas cooler is the major source of exergy destruction in the system. The total exergy destruction has the lowest value of 390.1 kW when the compressor inlet temperature is near the critical point (at 35 °C) and the compressor outlet pressure is comparatively low ( 24 MPa ). The optimum mass fraction (x) and efficiency of the cycle increase with turbine inlet temperature. The highest efficiency of 49% is obtained at the mass fraction of x = 0.74 and turbine inlet temperature of 700 °C. For predicting the cost of the system, the total heat transfer area coefficient ( U A T o t a l ) and size parameter (SP) are used. The U A T o t a l value has the maximum for the split mass fraction of 0.74 corresponding to the maximum value of thermal efficiency. The SP value for the turbine is 0.212 dm at the turbine inlet temperature of 700 °C and it increases with increasing turbine inlet temperature. However the SP values of the main compressor and re-compressor increase with increasing compressor inlet temperature.

ACS Style

Mohammad Saad Salim; Muhammad Saeed; Man-Hoe Kim. Performance Analysis of the Supercritical Carbon Dioxide Re-compression Brayton Cycle. Applied Sciences 2020, 10, 1129 .

AMA Style

Mohammad Saad Salim, Muhammad Saeed, Man-Hoe Kim. Performance Analysis of the Supercritical Carbon Dioxide Re-compression Brayton Cycle. Applied Sciences. 2020; 10 (3):1129.

Chicago/Turabian Style

Mohammad Saad Salim; Muhammad Saeed; Man-Hoe Kim. 2020. "Performance Analysis of the Supercritical Carbon Dioxide Re-compression Brayton Cycle." Applied Sciences 10, no. 3: 1129.