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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Society of Marine Engineering
Journal Basic Information
Journal DOI :
Korean Society of Marine Engineers
Editor in Chief :
Volume & Issues
Volume 7, Issue 2 - Apr 1983
Volume 7, Issue 1 - Feb 1983
Selecting the target year
Characteristics of Electrical Type Pressure Transducer Which uses Bourdon Tube
Journal of the Korean Society of Marine Engineering, volume 7, issue 1, 1983, Pages 14~22
The Bourdon tube pressure gauge is the most widely used primary detector for pressure in various kinds of fields recently. However in many cases lots of difficulties are encountered in telemetering, measuring the continuously changing pressure and recording as time goes by, etc. In this paper a Bourdon tube of flat-oval section is considered. On the basis of Wolf's theory, the very sensitive places are selected on the tube and full bridge arrangement is used. Then all of the characteristics are examined in order to use the pressure transducer practically into which the pressure gauge is converted. From the results, the error in meter reading is about
3% F.S., on the other hand, when measured with strain gauge, the error is within
1% F.S.. Also external acceleration on Bourdon tube hardly affect practical use.
Effects of Welding Parameters on the Weld Strength and Acoustic Emission in Friction Welding
Oh, Sae Kyoo ;
Journal of the Korean Society of Marine Engineering, volume 7, issue 1, 1983, Pages 23~33
A Study on the Precision Engine Indicatior(I) (Zero-shift Compensation of the Engine Indicator with a Electronic Device)
Journal of the Korean Society of Marine Engineering, volume 7, issue 1, 1983, Pages 34~39
Development of modern internal combustion engine requires more precise indicator. In the case of strain gage-strain tube type indicator, thermal expansion of the indicator's fixed part makes zero-shift in spite of water cooling. Therefore, the authors analyzed the cause of zero-shift phenomenon on strain gage-strain tube type indicator and proposed a new device to compensate the zero-shift of indicator by electrical method without detoriorating the dynamic charcteristic. As the results, we found that the zero-shift is varied linearlly according to temperature variation of the indicator's fixed part and appling a new device, we can improve the zero-shift of indicator about 0.63% (0.63 kg/
) of full scale, though we got 10% of it without the device at the cylinder head operating temperature (c.a.
A study on the suppress method of arc on a electromagnetic contactor
Journal of the Korean Society of Marine Engineering, volume 7, issue 1, 1983, Pages 40~48
Nowadays electromagnetic contactors are used for power on-off in various electrical loads. If the severe arc are occurred when power off, the magnetic contactor can not long run because of damage of contactor. In this paper, Authors indicate a method of how to minimize the arc when power off, Authors contrived a electronic circuit which can adjust the demagnetizing point of electro magnetic contactor, and control the demagnetizing point, utilizing our circuit, so as to occur the extinguish of arc at near the AC current zero point which is indispensibly exists. From the results of study, Authors could get confirmations the AC circuit could cut off with occurrence of mininum arc, and that possibility of extensive utilization of our method to hightension circuit.
Calculation of the coupled free, transverse vibrations of the multi-supported shaft system by transfer matrix method
Journal of the Korean Society of Marine Engineering, volume 7, issue 1, 1983, Pages 49~63
Coupled transverse shaft vibrations have become the target of great concern in high powered ships such as container ships. Due to increasing ship's dimensions and high propulsive power, resonance frequencies of the propeller shaft system tend to decrease and can appear in some cases within the operating speed range of engine. In this connection, the coupled free transverse vibrations of shaft system in two planes are theoretically investigated. This shaft system carries a number of discs and is flexibly supported by a number of bearing stiffness are considered for the calculation. Transfer matrix method is applied to calculate the shaft responses in both planes. A digital computer program is developed to calculate the shaft responses of the coupled transverse vibrations in two planes. An experimental model shaft system is made. It is composed of a disc, shafts, ball bearings thrust bearings and flexible bearing supports. The shaft system is excited by an electrical magnet, and shaft vibration responses in two planes are measured with the strain gage system. From these measurements, the natural frequencies of the shaft system in both planes are found out. The developed program is also used to calculate the shaft vibration responses of experimental model shaft system. From the results of these calculations, the natural frequencies of shaft system in two planes are derived. Theoretical predictions of model shaft natural frequencies show good agreements with its esperimental measurements.
Study on the characteristics of nucleate boiling heat transfer with changing of surface roughness
Journal of the Korean Society of Marine Engineering, volume 7, issue 1, 1983, Pages 64~78
In nucleate boiling, bubbles are created by the expansion of entrapped gas or vapor at small cavities in the surface of heat transfer. Namely, surface roughness is the important factor of heat transfer. This paper deals with the characteristics of boiling curve according to surface roughness. Freon-113 is used as the experimental fluid. The results are as follows; 1. In the case of the same as "q=C
", the lower numberical index "n", the larger heat transfer coefficient and the lower wall superheat "
T" is obtained for the rougher surface. 2. In the working of every kind of heat transfer sruface with boiling, improvement of capabilities of heat transfer can be devised by adding suitable roughness on the heat transfer surface. 3. When the metal nets of moderate mesh number are established, the capabilities of heat transfer can be improved in evaporation of liquid in vessels. But in the case that the sucession of bubbles in checked by using the nets which are too tight, the generation of bubbles union decreases critical heat flux. decreases critical heat flux.
The structures and mechanical properties of unidirectionally solidified Al-Fe-Ni alloy
Journal of the Korean Society of Marine Engineering, volume 7, issue 1, 1983, Pages 79~90
The examination for the changes of structures and mechanical properties in directionally solidified Al-Fe-Ni alloys containing the small amount of Fe and Ni was carried out by the varying the composition and solidification rate R of alloy, provided that the temperature gradient was 80 .deg.C/cm. The result were obtained as follows. A) In proportion to the increase of the solidification rate (R), the crystallized phase of this alloy was changed from the Ribbon-type structure to the Rod-type structure. B) The strength was rapidly increased in the changing process of composite shape from the Ribbon-type to the Rod-type with the solidification rate (R) increasing. C) The fiber stress (
) and Young's modulus (
) calculated for the Rod-type structure were 220 kg/
and 11, 800 kg/
respectively, which were in good accord with the rule of Mixtures.