• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.794_795
• /
• 2009

This paper presents an analysis method for a permanent magnet excited Transverse Flux Linear Motor (TFLM) with spiral core in a mover. The spiral core is used as mover core in order to make 3-dimensional magnetic flux path at the TFLM which has 3-dimensional magnetic flux flow. Magnetic field is analyzed by three-dimensional Equivalent Magnetic Circuit Network (EMCN) method. And an imaginary part, 'flux barrier,' is introduced to consider the spiral core characteristic. The computed thrust forces is compared to the measured results to show the effect of presented analysis method.

• Journal of Magnetics
• /
• v.18 no.2
• /
• pp.111-116
• /
• 2013

This paper presents a characteristic analysis method of a permanent magnet type transverse flux linear motor (TFLM) with spiral cores. The spiral cores are used as the mover cores in order to make 3-dimensional (3-D) magnetic flux paths at the TFLM which have 3-D magnetic flux flows. The 3-D Equivalent Magnetic Circuit Network Method is used to analyse the magnetic characteristics of the machine, and an imaginary part, 'flux barrier,' is introduced to consider the spiral core characteristic. Magnetic parameters such as flux, inductance, and thrust are calculated from the analysis results. The computed thrust forces are compared to measured values to confirm the accuracy of the analysis.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.2
• /
• pp.138-143
• /
• 2003

A double spiral thin-film inductor with a NiFe magnetic core is integrated with DC-DC converter IC. The NiFe core is deposited on a polyimide film as the thinckness of NiFe is 2.5~3.5 ${\mu}$m. Then, copper conductor line is deposited on the NiFe core with double spiral structure. Process integration is performed by sequential processes of etching the polyimide film deposited both top and bottom of the NiFe core and electroplation copper conductor line from exposed metal pad of the DC-DC converter IC. Process integration is simplified by elimination planarization process for top core because the proposed thin-film inductor has a bottom NiFe core only. Inductor of the fabricated monolithic DC-DC converter IC is 0.53 ${\mu}$H when the area of converter IC and thin-film inductor are 5X5$\textrm{mm}^2$ and 3.5X2.5$\textrm{mm}^2$, respectively. The efficiency is 72% when input voltage and output voltage are 3.5 V and 6 V, respectively at the operation frequency of 8 MHz.

• Progress in Superconductivity and Cryogenics
• /
• v.25 no.2
• /
• pp.19-24
• /
• 2023

Recently, interest in renewable energy such as solar and wind power has increased as an alternative to fossil fuels. Renewable energy sources such as large wind farms require long-distance power transmission because they are located inland or offshore, far from the city where power is required. High-Temperature Superconducting (HTS) power cables have more than 5 times the transmission capacity and less than one-tenth the transmission loss compared to the existing cables of the same size, enabling large-capacity transmission at low voltage. For commercialization of HTS power cables, unmanned operation and long-distance cooling technology of several kilometers is essential, and pressure drop characteristic is important. The cryostat's spiral corrugation tube is easier to bend, but unlike the round tube, the pressure drop cannot be calculated using the Moody chart. In addition, it is more difficult to predict the pressure drop characteristics due to the irregular surface roughness of the binder wound around the cable core. In this paper, a CFD model of a spiral corrugation tube with a core was designed by referring to the water experiments from previous studies. In the four cases geometry, when the surface roughness of the core was 10mm, most errors were 15% and the maximum errors were 23%. These results will be used as a reference for the design of long-distance HTS power cables.

• Journal of the Korean Magnetics Society
• /
• v.6 no.3
• /
• pp.179-188
• /
• 1996

This paper discussed on the impedance analysis of the planar air core inductors having spiral pattern and meander pattern. The width and distance of conductor, and number of turns were varied. As the width of conductor increased, both resistance and inductance decreased and there existed an maximum value in Q for spiral pattern. But Q increased with increasing width of conductor in meander pattern. In spiral pattern, there existed a distance between conductors where inductance became constant and Q became maximum, while the distance between conductors must be as large as possible to obtain large Q because the mutual inductance of meander pattern inductor has negative sign due to opposite current direction at adjacent conductor. Resistance and inductance increased with increasing the number of turns. There existed maximum Q at certain number of turns in spiral pattern. But Q became small in the meander pattern because increase of resistance was larger than increase of inductance with increasing number of turns.

• Journal of the Korean Society of Visualization
• /
• v.7 no.1
• /
• pp.14-20
• /
• 2009

In comparison with previous researches fur swirling flow, the spiral flow self-generated in the spiral flow nozzle has some different characteristics. It is not needed a compulsive tangential momentum to get its velocity component and has long potential core, relatively low swirl ratio, and high focusing ability. In this study, the self-generated mechanism of the spiral flow was clarified and the effect on the width of annular slit on spiral flow characteristics was investigated experimentally and numerically. As a result, the existence of tangential velocity component regardless of a compulsive angular momentum is clarified and the results obtained by experiment have a satisfactory agreement with those by numerical method, quantitatively and qualitatively.

• 한국가시화정보학회:학술대회논문집
• /
• 2007.11a
• /
• pp.143-148
• /
• 2007

In comparison with previous researches for swirling flow, the spiral flow self-generated in the spiral flow nozzle has some different characteristics. It is not needed a compulsive tangential momentum to get its velocity component and has long potential core, relatively low swirl ratio, and high focusing ability. In this study, the self-generated mechanism of the spiral flow was clarified and the effect on the width of annular slit on spiral flow characteristics was investigated experimentally and numerically. As a result, the existence of tangential velocity component regardless of a compulsive angular momentum is clarified and the results obtained by experiment have a satisfactory agreement with those by numerical method, quantitatively and qualitatively.

• Journal of Korea Water Resources Association
• /
• v.52 no.4
• /
• pp.235-243
• /
• 2019

Recently, urban inundation was frequently occurred due to the intensive rainfall exceeding marginal capacity of the flood control facility. Furthermore, needs for the underground storage facilities to mitigate urban flood are increasing according to rapidly accelerating urbanization. Thus, in this study, drainage efficiency in drain tunnel connecting to underground storage was investigated from the air-core measurements in the drop shaft against two types of inlet structure. In case of the spiral inlet, the multi-stage structure is introduced at the bottom of the inlet to improve the vortex induction effect at low inflow discharge (multi-stage spiral inlet). The average cross-sectional area of the air-core in the multi-stage spiral inlet is 10% larger than the tangential inlet, and show the highly air emission effect and the highly inflow efficiency at the high inflow discharge. In case of the tangential inlets, the air emission effect decreased after exceeding the maximum inflow discharge, which is required to maintain the inherent performance of the tangential inlet. From the measurements, the empirical formula for the cross-sectional area of the air-core according to locations inside the drop shaft was proposed in order to provide the experimental data available for the inlet model used in experiments.

• Progress in Superconductivity and Cryogenics
• /
• v.10 no.4
• /
• pp.33-37
• /
• 2008

The main objective of this study is to identify the pressure drop characteristics of coolant flow passages of 154kV/1GVA High Temperature Superconducting (HTS) power cable, experimentally. The passages were consisted of two parts, the one is the circular path with spiral ribs in the core to cool the cable conductor layer and the other is annular path with spirally corrugated outer wall to cool the shield layer. Thus the experiments to acquire the pressure drop data were performed with two types of circular spiral tubes and eight types of the concentric annuli in various range of Reynolds number. The pressure drops in the core tubes and the annuli were much higher than those in the tubes with smooth surface. Therefore, modified correlations to present the experimental results in each flow passage were suggested.

• Steel and Composite Structures
• /
• v.20 no.6
• /
• pp.1259-1274
• /
• 2016

A precast composite column system has been developed in this study by utilizing multi interlocking spiral steel into a centrifugally-formed hollow-core precast (CHPC) column. The proposed hybrid column system can have enhanced performances in the composite interaction behavior between the hollowed precast column and cast-in-place (CIP) core-filled concrete, the lap splice performance of bundled bars, and the confining effect of concrete. In the experimental program, reversed cyclic loading tests were conducted on a conventional reinforced concrete (RC) column fabricated monolithically, two CHPC columns filled with CIP concrete, and two steel-reinforced concrete (SRC) columns. It was confirmed that the interlocking spirals was very effective to enhance the structural performance of the CHPC column, and all the hollow-core precast column specimens tested in this study showed good seismic performances comparable to the monolithic control specimen.