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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Mechanical Engineers B
Journal Basic Information
Journal DOI :
The Korean Society of Mechanical Engineers
Editor in Chief :
Volume & Issues
Volume 35, Issue 12 - Dec 2011
Volume 35, Issue 11 - Nov 2011
Volume 35, Issue 10 - Oct 2011
Volume 35, Issue 9 - Sep 2011
Volume 35, Issue 8 - Aug 2011
Volume 35, Issue 7 - Jul 2011
Volume 35, Issue 6 - Jun 2011
Volume 35, Issue 5 - May 2011
Volume 35, Issue 4 - Apr 2011
Volume 35, Issue 3 - Mar 2011
Volume 35, Issue 2 - Feb 2011
Volume 35, Issue 1 - Jan 2011
Selecting the target year
Comparative Study on Energy Consumption in Steam-Humidification- and Water-Spray-Humidification-Type Outdoor Air-Conditioning Systems for Semiconductor Manufacturing Clean Rooms
Kim, Hyung-Tae ; Song, Gen-Soo ; Kim, Ki-Cheol ; Yoo, Kyung-Hoon ; Son, Seung-Woo ; Shin, Dae-Kun ; Park, Dug-Jun ; Kwon, Oh-Myung ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1249~1255
DOI : 10.3795/KSME-B.2011.35.12.1249
In modern large-scale semiconductor manufacturing clean rooms, the energy consumed by the outdoor air-conditioning system during heating, humidification, cooling, and dehumidification of the incoming outdoor air represents about 45% of the total air-conditioning load required to maintain a clean-room environment. In particular, the energy required for humidification of the outdoor air in winter is very high. Therefore, evaluation and comparison of the energy consumption in key humidification systems, viz., steam-humidification and water-spray-humidification systems, used in outdoor air-conditioning systems would be useful to reduce the outdoor air-conditioning load in clean rooms. In the present study, an experiment with an outdoor air flow of 1000
/h was conducted to compare the air-conditioning process and energy consumption in outdoor air-conditioning systems with electrodeboiler steam humidifiers and air-washer water spray humidification systems. The experimental results showed that the water-spray-humidification-type outdoor air-conditioning system consumed less electrical power than did the steam-humidification-type system and was more energy efficient during winter.
3D RANS Simulation and the Prediction by CRN Regarding NOx in a Lean Premixed Combustion in a Gas Turbine Combustor
Yi, Jae-Bok ; Jeong, Dae-Ro ; Huh, Kang-Yul ; Jin, Jae-Min ; Park, Jung-Kyu ; Lee, Min-Chul ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1257~1264
DOI : 10.3795/KSME-B.2011.35.12.1257
This paper presents 3D simulation by STAR-CCM+ for lean premixed combustion in a stationary gas turbine combustor with separate pilot and main nozzles. The constant for the source term in the flame area density transport equation was modified to account for a low global equivalence ratio and validated against measurement data. A Partially-premixed Coherent Flame Model(PCFM) involves propagation of a laminar premixed flame with the predicted flame surface density and equilibrium assumption in the burned gas with spatial inhomogeneity. The conditions for cooling by radiation and convection are considered for accurate determination of the heat flux on the wall. A parametric study is of the pilot-fuel-to-total-fuel-ratio is carried out. A chemical reactor network (CRN) was constructed on the basis of the 3D simulation results and compared against measurements of NOx.
Numerical and Experimental Study on Recirculation Flow Driven by an AC Electromagnetic Force in a Circular Container
Suh, Ga-Hyun ; Suh, Seung-Gyu ; Choe, Jong-Geun ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1265~1272
DOI : 10.3795/KSME-B.2011.35.12.1265
We performed numerical simulations of the recirculation flow of an electrolyte fluid in a circular container driven by an AC electromagnetic force for solving continuity and momentum equations. We also conducted an experiment to obtain flow data, which were in good agreement with the numerical simulation results. Furthermore, we performed a parametric study on both numerical and experimental aspects and found that the fluid velocity increases with an increase in the electrolyte concentration and magnetic intensity and with a decrease in the fluid depth and AC frequency.
Aerodynamic Characteristics of Giromill with High Solidity
Lee, Ju-Hee ; Yoo, Young-So ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1273~1283
DOI : 10.3795/KSME-B.2011.35.12.1273
A 3-dimensional unsteady numerical analysis has been performed to evaluate the aerodynamic characteristics of a Giromill. Generally, the structure of a Giromill is simple and therefore easy to develop. In addition, the high solidity of the Gironmill helps improve the self-starting capacity at a low tip speed ratio (TSR). However, contrary to the Darrieus wind turbine which has a TSR of 4-7, a Giromill has a low TSR of 1-3. In this study, the aerodynamic characteristics of the Giromill are investigated using computational fluid dynamics (CFD). Three straight-bladed wings are used, and the solidity of the Giromill is 0.75. In contrast to a Darrieus wind turbine having low solidity, the Giromill shows a sudden decrease in the aerodynamic performance because of the interference between the wings and an increase in the drag on the wings in the downstream direction where wind flow is significantly reduced. Consequently, the aerodynamic performance decreased at a TSR value lower than 2.4.
Experimental Study on the Control Characteristics of Each Channel in a Semiconductor Chiller
Kim, Hyeon-Joong ; Kwon, Oh-Kyung ; Cha, Dong-An ; Kim, Yong-Chan ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1285~1292
DOI : 10.3795/KSME-B.2011.35.12.1285
The characteristics of a semiconductor chiller system with EEV have been experimentally studied. Three experiments on temperature changes (increase and decrease), load variation, and control precision were conducted to investigate the operating characteristics of the semiconductor chiller. The power consumption was 8.9 kW during increase in temperature. The required time was 37.5 min for CH1 and 39.5 min for CH2. Moreover, the time required for falling temperature was 26.5 min. The control precision for partial load operation was relatively low compared to that of a full load operation. In addition, the CH2 equipped with a step motor showed better control precision. The power consumed by the chiller for process cooling water was 1.8 kW, which was one-half of that consumed during the refrigeration cycle. The objective of this study is to provide an optimal control guideline for the semiconductor chiller design.
Characteristics of the Water Pressure Drop Considering Heat Transfer in the Evaporator and Condenser of a Water Chiller
Nguyen, Minh Phu ; Lee, Geun-Sik ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1293~1300
DOI : 10.3795/KSME-B.2011.35.12.1293
The configurations of the evaporator and condenser of a water chiller can be determined from the trade-off between the heat transfer area, which is related to the capital cost and the pressure drop, which is associated with the operational cost. In this study, the design of the water chiller focused on minimizing the water pressure drop of both condenser and evaporator for given cooling capacity and requirements. Commercial enhanced tubes were employed to simulate real-life conditions. The results of the present analysis were compared with those obtained by HTRI software for verifying them. The results indicated that a reduction in the water pressure drop, which is associated with the short length of a tube, can be effected by decreasing the number of tube passes and increasing the number of tubes and the tube diameter. However, using a large number of tubes with smaller diameters can reduce the capital cost because the tubes are short. The reduction of the capital cost is due to the fact that a small-diameter tube has low internal thermal resistance and hence contributes to a decrease in the overall thermal resistance per unit length.
Relationship between Restoring Force and Typical Stroke with SMA Coil Spring in Electrosurgical Knee Wand
Yang, Young-Gyu ; Han, Gi-Bong ; Kim, Cheol-Woong ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1301~1307
DOI : 10.3795/KSME-B.2011.35.12.1301
Electrosurgical knee wand (EKW) is a high-frequency thermocautery instrument and is often used for coagulation, ablation, excision, and extirpation of knee ligaments and tissues. In order to maximize the success rate, ease, and safety of knee surgery using EKW and radiofrequency ablation, it is necessary to ensure that the EKW selectively approaches the lesion with utmost accuracy and safety. The key feature of this instrument is its excellent maneuverability. Hence, the authors constructed a tensile spring model based on a shape memory alloy (SMA), which exhibits the shape memory effect. This model can be used in knee surgery as it is considered the most biocompatible femorotibial surgical actuator. The changes in external temperature with current and the thermoelectric characteristics of the SMA were investigated. The relationship between the restoring force and the typical stroke (TS) in response to the conditions in the SMA tensile spring design were evaluated. In conclusion, as the diameter of the SMA tensile spring decreased, the maximum temperature increased. The strain in the actuator caused a stable and proportional increase in the force and induced current for up to 15s, but this increase became very unstable after 30s. Moreover, the relationship between the current and the TS was more stable than that between the current and the restoring force.
High-Speed RNA Isolation Using Magnetic Oligo(dT) Beads and Lateral Magnetophoresis
Lee, Hwan-Yong ; Han, Song-I ; Han, Ki-Ho ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1309~1316
DOI : 10.3795/KSME-B.2011.35.12.1309
This paper presents a high-speed RNA microextractor for the direct isolation of RNA from blood lysate using magnetic oligo(dT) beads. The extraction is performed through lateral magnetophoresis, which is induced by a ferromagnetic wire array inlaid. With this RNA microextractor, more than 80% of the magnetic beads could be separated at a flow rate up to 20 ml/h, and the overall extraction procedure was completed within 1 min. The absorbance ratio of RNA to protein(A260/A280) was greater than 1.7, indicating that the extraction technique yields pure RNA. The feasibility of using this technique in reverse transcription polymerase chain reaction procedures was investigated by cDNA synthesis and PCR processes. The results confirmed that the RNA microextractor is a practical device for easy, fast, and high-precision RT-PCR using minimal amounts of reagent.
Study of Aerosol Light Absorption Measurement Operated in a Vehicle Using an Interferometer
Lee, Jeong-Hoon ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1317~1324
DOI : 10.3795/KSME-B.2011.35.12.1317
We propose a method operated in a vehicle to measure light absorption of particles in atmosphere. The advantage of this method is that it is insensitive to light scattering and hence can be used for the direct measurement of the light absorption coefficient without suffering from light scattering. With this method atmospheric light absorption can be measured at a time constant of 10 s. Further, our method allows for the real-time measurement of light absorption near a highway. The light absorption coefficients were high near a race track, an airport and the main gate where vehicles emitted carbonaceous particles.
Analytical, Numerical, and Experimental Comparison of the Performance of Semicircular Cooling Plates
Cho, Kee-Hyeon ; Kim, Moo-Hwan ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1325~1333
DOI : 10.3795/KSME-B.2011.35.12.1325
An analytical, numerical, and experimental comparison of the hydraulic and thermal performance of new vascular channels with semicircular cross sections was conducted. The following conditions were employed in the study: Reynolds number, 30-2000; cooling channels with a volume fraction of the cooling channels, 0.04; and pressure drop,
Pa. Three flow configurations were considered: first, second, and third constructal structures with diameters optimized for hydraulic operations. To validate the proposed vascular designs by an analytical approach, 3-D numerical analysis was performed. The numerical model was also validated by the experimental data, and the comparison results were in excellent agreement in all cases. The validation study against the experimental data showed that compared to traditional channels, the optimized structure of the cooling plates could significantly enhance heat transfer and decrease pumping power.
An Experimental Study of Local Mass Transfer Characteristics on Inclined Flat Plate
Yoo, Seong-Yeon ; Jo, Woo-Sik ; Cho, Woong-Sun ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1335~1341
DOI : 10.3795/KSME-B.2011.35.12.1335
The purpose of this research is to investigate how separated and reattached flow affects mass transfer, by comparing the local mass transfer characteristics on an inclined flat plate with those on a parallel flat plate. The local mass transfer coefficients for the flat plate were measured using the naphthalene sublimation technique; the inclined angle of the flat plate was varied from
intervals, and the free-stream velocity was varied from 2m/s to 15m/s. At positive inclined angles, the local Sherwood numbers decreased gradually because the boundary-layer thickness increased. On the other hand, for negative inclined angles, the local Sherwood numbers assumed the minimum value at the separation point of the recirculation flow and the maximum value at the reattachment point. The average Sherwood numbers for both positive and negative inclined angles were lower than those in the case of the parallel plate.
Power Enhancement Potential of a Low-Temperature Heat-Source-Driven Rankine Power Cycle by Transcritical Operation
Baik, Young-Jin ; Kim, Min-Sung ; Chang, Ki-Chang ; Lee, Young-Soo ; Ra, Ho-Sang ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1343~1349
DOI : 10.3795/KSME-B.2011.35.12.1343
In this study, the power enhancement potential of a Rankine power cycle by transcritical operation was investigated by comparing the power of an HFC-134a subcritical cycle with that of an HFC-125 transcritical cycle, for a low-grade heat source with a temperature of about
. For a fair comparison using different working fluids, each cycle was optimized by three design parameters from the viewpoint of power. In contrast to conventional approaches, the working fluid`s heat transfer and pressure drop characteristics were considered in the present approach, with the aim of ensuring a more realistic comparison. The results showed that the HFC-125 transcritical cycle yields 9.4% more power than does the HFC-134a subcritical cycle under the simulation conditions considered in the present study.
Statistical Analysis on Residuals from No-Fault Reference Models of a Residential Heat Pump System in Normal Cooling Operation
Kim, Min-Sung ; Yoon, Seok-Ho ; Baik, Young-Jin ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1351~1358
DOI : 10.3795/KSME-B.2011.35.12.1351
To approximate the threshold of the fault detection and diagnosis (FDD) system, validation of the measurements is mandatory. Naturally, the system shows uncertainties due to measuring sensors - mostly thermocouples or RTDs - and due to repeatability. The uncertainty of a thermocouple comes from natural variation or a drift of the thermocouple measurement. Considering the natural variation behaves like zero-mean white noise, its natural variation can be characterized closely by the steady-state standard deviation. However, residuals between measurements and no-fault references in FDD systems show a statistical distribution with various uncertainties. In this paper, steady-state variations of measurement residuals were investigated by utilizing built-in temperature sensors in a heat pump for the model development and the final application.
Effect of Ethanol Content on Fine Soot Particle Emission from a Diesel-Ethanol Blended Fuel Diesel Engine
Park, Su-Han ; Cha, June-Pyo ; Kwon, Seok-Ju ; Park, Sung-Wook ; Lee, Chang-Sik ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1359~1365
DOI : 10.3795/KSME-B.2011.35.12.1359
The purpose of this study is to investigate the effect of ethanol content on the emission of nanosized particles from a diesel-ethanol blended fuel engine. The engine combustion and exhaust emission characteristics of a singlecylinder diesel engine were analyzed using an emission analyzer and an SMPS(scanning mobility particle sizer). The analysis revealed that soot emission increased with the ignition delay. When the ignition delay was fixed, an increase in the ethanol content caused a decrease in the soot emission. With an increase in the ethanol blending ratio, the number concentration and mass distribution of nanosized particles generally decreased. However, for 30% ethanol blending, large particles were observed because of the agglomeration of soot particles, and consequently, the particle mass increased.
Experimental Study on Compression/Absorption High-Temperature Hybrid Heat Pump with Natural Refrigerant Mixture
Kim, Ji-Young ; Park, Seong-Ryong ; Baik, Young-Jin ; Chang, Ki-Chang ; Ra, Ho-Sang ; Kim, Min-Sung ; Kim, Yong-Chan ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1367~1373
DOI : 10.3795/KSME-B.2011.35.12.1367
This research concerns the development of a compression/absorption high-temperature hybrid heat pump that uses a natural refrigerant mixture. Heat pumps based on the compression/absorption cycle offer various advantages over conventional heat pumps based on the vapor compression cycle, such as large temperature glide, temperature lift, flexible operating range, and capacity control. In this study, a lab-scale prototype hybrid heat pump was constructed with a two-stage compressor, absorber, desorber, desuperheater, solution heat exchanger, solution pump, liquid/vapor separator, and rectifier as the main components. The hybrid heat pump system operated at 10-kW-class heating capacity producing hot water whose temperature was more than
when the heat source and sink temperatures were
. Experiments with various
mass fractions and compressor/pump circulation ratios were performed on the system. From the study, the system performance was optimized at a specific
Understanding Pollutant Emission in a Heavy-Duty Diesel Engine with JP-8 and Diesel
Lee, Jin-Woo ; Bae, Choong-Sik ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1375~1381
DOI : 10.3795/KSME-B.2011.35.12.1375
Combustion processes in an optically-accessible single-cylinder heavy-duty diesel engine equipped with a highpressure common-rail injection system were investigated for JP-8 and diesel. Direct imaging and two-color thermometry were employed to verify the emission trend for both fuels. The combustion process was characterized by image analysis with focus on luminosity. The results of two-color thermometry were analyzed on the basis of the flame temperature and KL factor distribution. Analysis of the combustion process by direct imaging showed that the ignition delay was longer for JP-8 than for diesel, while the flame was extinguished rapidly. Analysis of the flame luminosity showed that the combustion intensity was higher for diesel and that the flame lasted for a longer duration in this case. Two-color thermometry results showed that the high-temperature region extended over a large area during JP-8 combustion, implying the formation of a large amount of
. In addition, the KL factor showed low level over a large area and relatively homogeneous in the case of JP-8 combustion, which implied that less smoke was produced when using this fuel.
Numerical Analysis of Heat Transfer in Multichannel Volumetric Solar Receivers
Lee, Hyun-Jin ; Kim, Jong-Kyu ; Lee, Sang-Nam ; Kang, Yong-Heack ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1383~1389
DOI : 10.3795/KSME-B.2011.35.12.1383
The current study focuses on the consistent analysis of heat transfer in multichannel volumetric solar receivers used for concentrating solar power. Changes in the properties of the absorbing material and channel dimensions are considered in an optical model based on the Monte Carlo ray-tracing method and in a one-dimensional heat transfer model that includes conduction, convection, and radiation. The optical model results show that most of the solar radiation energy is absorbed within a very small channel length of around 15 mm because of the large length-to-radius ratio. Classification of radiation losses reveals that at low absorptivity, increased reflection losses cause reduction of the receiver efficiency, notwithstanding the decrease in the emission loss. As the average temperature increases because of the large channel radius or small mass flow rate, both emission and reflection losses increase but the effect of emission losses prevails.
Design and Performance Analysis of Steam Turbine for Variations of Degree of Reaction
Shin, Jung-Ha ; Lee, Geun-Sik ;
Transactions of the Korean Society of Mechanical Engineers B, volume 35, issue 12, 2011, Pages 1391~1398
DOI : 10.3795/KSME-B.2011.35.12.1391
Design and performance analysis of a steam turbine for variations of degree of reaction were performed by computer simulation. Design parameters such as blade angles, exit areas, and heights of the nozzle and moving blade were represented as functions of the degree of reaction. The main performance factors such as turbine power, diagram efficiency, and axial thrust were also expressed in terms of the degree of reaction. For further information about the design and performance, the blade angles and main performance factors were investigated as functions of the flow coefficient. The turbine power and diagram efficiency reached a maximum value for a given degree of reaction and flow coefficient, and the symmetric shape of the moving blade showed distortion as the degree of reaction was increased.