• Title/Summary/Keyword: Surface stabilizer

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Experimental Study on the Surface Pressure Characteristics of a Rear-Guider for the Various Design Factors of a Cross-Flow Fan (관류홴의 설계인자 변화에 따른 리어가이더의 표면압력 특성에 관한 실험적 연구)

  • Kim, J.K.
    • Journal of Power System Engineering
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    • v.9 no.3
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    • pp.50-57
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    • 2005
  • A cross-flow fan is strongly influenced by the various design factors of a rear-guider and a stabilizer. The purpose of this paper is to investigate the effects of a rear-guider and a stabilizer on the surface pressure of a rear-guider in an indoor room air-conditioner using a cross-flow fan. The design factors considered in this paper are a rear-guider clearance, a stabilizer clearance, and a stabilizer setup angle, respectively. The operating condition of a cross-flow fan was controlled by changing the static pressure and flowrate using a fan tester. All surface pressures of a rear-guider are differently distributed according to the stabilizer setup angle, and show a zero value in the flow coefficient, ${\Phi}{\fallingdotseq}0.5$ only of a stabilizer setup angle, $45^{\circ}$. Especially, they show a big negative value in the expansion angle larger than $34^{\circ}$ regardless of a rear-guider clearance, a stabilizer clearance, and a stabilizer setup angle. On the other hand, surface pressures for various stabilizer cutoff clearances are better than those for various rear-guider clearances.

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Reinforcement effect of surface stabilizer using surface curtain walls on aging reservoirs

  • Song, Sang-Huwon;Cho, Dae-Sung;Seo, Se-Gwan
    • Geomechanics and Engineering
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    • v.28 no.1
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    • pp.1-10
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    • 2022
  • In Korea, accidents related to the collapse of deteriorated aging reservoirs occur every year. The grouting method is generally applied to reinforce an aging reservoir. However, when using this method, different reinforcing effects appear depending on the ground conditions. Thus, new construction methods and materials capable of providing consistent reinforcing effects are required. In this study, the direct shear test (DST), model test, and simulation analysis were performed to evaluate the impact of surface stabilizers, generally used to reinforce roads, rivers, and slopes of roads, applied using surface curtain walls on aging reservoirs. The DST results indicate that when the surface stabilizer was mixed with in-situ soil, the increase in cohesion was the highest at a mixing ratio of 9%. No changes in the friction angle were evident; therefore, 9% was determined to be the optimal mixing ratio. In addition, the model test and simulation analysis showed that when 9% of the surface stabilizer was mixed and applied to the aging reservoir, the seepage quantity of water and the saturated area were reduced by approximately 42% and 73%, respectively. Moreover, the comprehensive analysis of results showed that the grouting method could be completely replaced by surface stabilizers applied through surface curtain walls because the technique could secure stability by decreasing the seepage in the aging reservoir.

Performance Analysis of Stabilizer Fin Applied Coanda System (코안다 시스템이 장착된 안정기용 핀의 성능해석)

  • Seo, Dae-Won;Lee, Se-Jin;Oh, Jungkeun
    • Journal of Ocean Engineering and Technology
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    • v.30 no.1
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    • pp.18-24
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    • 2016
  • Stabilizer fins are installed on each side of a ship to control its roll motion. The most common stabilizer fin is a rolling control system that uses the lift force on the fin surface. If the angle of attack of a stabilizer fin is zero or the speed is zero, it cannot control the roll motion. The Coanda effect is well known to generate lift force in marine field. The performance of stabilizer fin that applies the Coanda effect has been verified by model tests and numerical simulations. It was found that a stabilizer fin that applied the Coanda effect at Cj = 0.085 and a zero angle of attack exactly coincided with that of the original fin at α = 26°. In addition, the power needed to generate the Coanda effect was not high compared to the motor power of the original stabilizer fin.

An Experimental Study on Optimal Mixture Ratio of Hardening Agent for Surface Soil Stabilization (연약지반 표층안정처리를 위한 고화재의 최적조합 산정에 관한 실험적 연구)

  • 천병식;김진춘;최현석
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.17-24
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    • 2000
  • Hardening agent has been the traditional material for surface soil stabilization of soft ground. This study aims at determining optimal mixture ratio of hardening agent in accordance with the required design specifications. Hardening agent is properly mixtured with Fly ash, Gypsum, Slag and Cement for the ettringite hydrates which is effective for early stabilization of unconsolidated soil. The treated soil is the clay which are widely found here and there in Korea. In this study, preliminary tests were performed to get optimal mixture ratio of stabilizer ingredient, and marine clay in Jin-Hae was used to get physical and chemical properties. Laboratory tests of 50 stabilized soil were peformed to get optimal mixture ratio for 16 stabilizer material of 6 type, and stabilizer mixing was determined.

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A Study on the Surface Soil Stabilization Method on Marine Clay (해성점성토의 표층안정처리 공법에 관한 연구)

  • 천병식;한기열
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2000.10a
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    • pp.129-134
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    • 2000
  • Hardening agent has been the traditional material for surface soil stabilization a sat ground This study aims at determining optimal mixture ratio of hardening agent in accordance with the required design specificutions. Hardening agent is properly mixed with Fly ash, Gyosum, Slag and Cement for the etmmngite hydrates which is dective for early stabilization of unconsoliokrred soil. \ulcornerhe treated soil is the clay tint is widely found here and there in Koresz In this study, preliminary tests were performed to get optirml mixture ratio of stabilizer ingredient, and mrvine clay in Jin-Hae was used to get physid and Md properties. Labomtory tests of 50 stabilized soil were performed to get optimal mixture mtio for 16-stabilizer merial a 6 types, a d stabilizer mixing was determined

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A Study on the Surface Soil Stabilization on Marine Clay by the Hardening Agent (고화재에 의한 해성점성토의 표층안정처리에 관한 연구)

  • 천병식;양진석
    • Journal of Ocean Engineering and Technology
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    • v.15 no.1
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    • pp.92-97
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    • 2001
  • Hardening agents have been the traditional material for surface soil stabilization of soft ground. This study aims at determining the optimal mixture ratio of the hardening agent in accordance with the required design specifications. Hardening agents which consists of fly ash, gypsum, slag and cement for the ettringite hydrates is effective for early stabilization of unconsolidated soil. The raw ground material is the clay that is widely found in Korea. In this study, preliminary tests were performed to get an optimal mixture ratio of the stabilizer ingredient and marine clay from Jinhae was used to get physical and chemical properties. Laboratory tests of 50 stabilized soils were performed to get an optimal mixture ratio for 16-stabilizer materials of 6 types, and a mixture ratio of the stabilizer ingredient and marine clay was determined.

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Cavitation-Erosion Characteristics of the Stainless Steel with Adding Ti Stabilizer Element in Sea Water (안정화 원소 Ti 첨가에 따른 스테인리스강의 해수 내 캐비테이션-침식 특성)

  • Choi, Yong-Won;Yang, Ye-Jin;Kim, Seong-Jong
    • Journal of the Korean institute of surface engineering
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    • v.49 no.4
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    • pp.344-348
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    • 2016
  • Stainless steel is widely applied in many industrial fields due to its excellent anti-corrosion and durability characteristics. However, stainless steel is very vulnerable to cavitation attack caused by high speed flow of fluid in the chloride environments such as marine environment. These conditions promote intergranular corrosion and cavitation-erosion, leading to degradation of the structural integrity and service life. In order to prevent these problems, the stabilized stainless steel is applied to the offshore and shipbuilding industries. In this study, Ti was added to 19%Cr-9%Ni as the stabilizer element with different concentrations (0.26%, 0.71%), and their durabilities were evaluated with cavitation-erosion experiment by a modified ASTM G32 method. The microstructural change was observed with the stabilizer element contents. The result of the observation indicated that the amount of carbide precipitation was decreased and its size became finer with increasing Ti content. In the cavitation-erosion experiment, both weight loss and surface damage depth represented an inverse proportional relationship with the amount of Ti element. Consequently, the stainless steel containing 0.71% of Ti had excellent durability characteristics.

Comparison of Activity of the Muscles around the Shoulders during Push Up and Push Up Plus Exercises under Diverse Stabilization Conditions

  • Lee, Han Ki;Lee, Jun Cheol;Yoon, Seong Min
    • Journal of International Academy of Physical Therapy Research
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    • v.6 no.1
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    • pp.815-823
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    • 2015
  • This study aimed to examine the most effective exercise method for shoulder joint rehabilitation by comparatively observing activity of shoulder stabilizer muscles during push up and push up plus exercises under diverse stable conditions. The subjects were 20 healthy adults students who went to M university. While the subjects conducted push up and push up plus exercises under diverse stable conditions(a stable surface, a support of 25cm height, a support of 30 cm height and a balance pad), activities of the upper trapezius muscle, pectoralis major muscle, serratus anterior muscle, and triceps brachii muscle were recorded. During push up and push up plus exercises, activities of the stabilizer muscles were higher when the stable condition was changed rather than on the stable surface. In particular, when the support of 30cm height and balance pads were applied, activity of the shoulder stabilizer was highest. There were significant differences in the upper trapezius muscle and triceps brachii muscle during the push up exercise(p<.05) and in the serratus anterior muscle during the push up plus exercise(p<.05). Activities of the shoulder stabilizers were higher when the upper and lower limbs' surface stable conditions were changed than the stable surface. Therefore, when programs for rehabilitation of shoulder joints are applied, provision of diverse stable conditions according to patients' conditions will be effective methods.

Characteristics of Desiccation on the Stabilized Layer in Waste Landfill (쓰레기 매립지에서 표층고화처리층의 건조수축특성)

  • 천병식;임종윤;최창현;차용혁
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.301-308
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    • 1999
  • With the shortage of the land and NIMBY syndrome, it is issued recently that the capacity of waste-landfill site is needed though the decreasing tendency of waste landfill. From this point, the stability is the most essential problem in the landfill that will be constructed. Advanced design and construction are most important for that. In this paper, for the study of desiccation, dry-shrinkage crack from drying and chemical reaction in cement hydration, which is occurred when the surface layer stabilization method is applied in wast landfill, laboratory test of the ground and specimen according to the mixture ratio of stabilizer is performed. From the result, it is notified that the uni-axial strength increases with the stabilizer, but dry-shrinkage increases too, therefore, it is important and the goal of this study to find the optimal mixture ratio of each stabilizer. Analysis of variance for regression with acting variables is performed to find optimal mixture ratio of each stabilizer.

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The Evaluation of Optimum Hardening Agent Mixture Ratio for Surface Stabilization on Extremely Soft Marine Clay (초연약해성점성토 지반의 표층안정처리를 위한 최적고화재 배합비 산정에 관한 연구)

  • 천병식;한기열
    • Proceedings of the KSR Conference
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    • 2001.05a
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    • pp.408-415
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    • 2001
  • Hardening agent has been the traditional material for surface soil stabilization of soft ground. The aim of this study if to determine optimal mixture ratio of hardening agent in accordance with the required design specifications. Hardening agent consists of fly ash, gypsum, slag and cement for the ettringite hydrates and if effective for early stabilization of unconsolidated soil. The raw ground material is the clay that is widely found here and there in Korea. In this study, preliminary tests were performed to get optimal mixture ratio of stabilizer ingredient and marine clay in Jinhae was used to get physical and chemical properties. Laboratory tests of 50 stabilized soils were performed to get optimal mixture ratio for 16-stabilizer materials of 6 types, and mixture ratio of stabilizer ingredient and marine clay was determined.

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