• Title/Summary/Keyword: Air-Cushion

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Experimental investigations on the resistance performance of a high-speed partial air cushion supported catamaran

  • Yang, Jinglei;Lin, Zhuang;Li, Ping;Guo, Zhiqun;Sun, Hanbing;Yang, Dongmei
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.38-47
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    • 2020
  • The partial air cushion supported catamaran (PACSCAT) is a novel Surface Effect Ship (SES) and possesses distinctive resistance performance due to the presence of planing bottom. In this paper, the design of PACSCAT and air cushion system are described in detail. Model tests were carried out for Froude numbers ranging from 0.1 to 1.11, the focus is on the influence of air cushion system on resistance characteristics. Drag-reducing effect of air cushion system was proved by means of contrast tests in cuhionborne and non-cushionborne mode. Wave-making characteristics reflect that the PACSCAT would eventually enter planing regime, in which the air could just escape under the seals and the hull body could operate in a steady state. To acquire different air cushion pressure, air flow rate and leakage height were adjusted during tests. Experimental results show that the resistance performance in planing regime would decrease evidently as the increased air flow rate, however, the scheme with medium leakage height presents the best resistance performance in the hump region.

The Study on the Evaluation of Contact Pressure of Wheelchair Seat Cushion (횔체어 시트쿠션의 접촉 압력 평가에 관한 연구)

  • Kang, Young-Sig;Yang, Sung-Hwan;Cho, Mun-Son;Sin, You-Min
    • Proceedings of the Safety Management and Science Conference
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    • pp.61-69
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    • 2010
  • The users who use the wheelchair are confined to a wheelchair for a long time. Accordingly, the use of seat cushion for pressure distribution is very important in order to prevent a bedsore. Therefore, this paper provides useful information for design of seat cushion through statistical testing among nothing cushion, low cell type of air cushion, high cell type of air cushion, and jelly type of air cushion. It turned out that the jelly type and high cell type of air cushion have a serious effect on decision and design of seat cushion.

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Quantitative Monitoring of Body Pressure Distribution Using Built-in Optical Sensors

  • Lee, Kang-Ho;Kwon, Yeong-Eun;Seo, Jihyeon;Lee, Byunghun;Lee, Dongkyu;Kwon, Ohwon
    • Journal of Sensor Science and Technology
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    • v.29 no.5
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    • pp.279-282
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    • 2020
  • In this study, body pressure was quantitatively detected using built-in optical sensors, inside an air cushion seat. The proposed system visualizes the effect of the body pressure distribution on the air cushion seat. The built-in sensor is based on the time-of-flight (ToF) optical method, instead of the conventional electrical sensor. A ToF optical sensors is attached to the bottom surface of the air-filled cells in the air cushion. Therefore, ToF sensors are durable, as they do not come in physical contact with the body even after repeated use. A ToF sensor indirectly expresses the body pressure by measuring the change in the height of the air-filled cell, after being subjected to the weight of the body. An array of such sensors can measure the body pressure distribution when the user sits on the air cushion seat. We implemented a prototype of the air cushion seat equipped with 7 ToF optical sensors and investigated its characteristics. In this experiment, the ToF optical pressure sensor successfully identified the pressure distribution corresponding to a sitting position. The data were accessed through a mobile device.

Development of Air Cushion Transporter Using the Pneumatic Floating Pad (공기부양판을 적용한 에어쿠션 트랜스포터의 개발)

  • Jung, Hyunmok;Hong, Junhee;Yun, Dongwon;Park, Heechang;Kim, Byungin;Lee, Sunghwi
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.25 no.5
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    • pp.338-344
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    • 2016
  • Recent trends in transport system for carrying heavy freight are that demands of a high efficiency, economic efficiency, convenience and safety are increased. Conventional transport systems were poor in transport efficiency and economic efficiency. And Safety problems can be caused to products and workers. In order to overcome these problems, an air cushion transport device with a high-pressure air is required. The air cushion transporter is a device for reducing the frictional force of floor surface and lifting the heavy freight by spraying the high-pressure air to the floor. Technology to float and transfer freight using high-pressure air is very convenient and initial cost can be reduced. In this paper, the study on the levitation performance and transport efficiency of air cushion transport system is conducted and verified that air cushion transporter has a significantly higher transport efficiency than conventional heavy handling systems.

Development of the Air Cushion Carrier Equipment for Carrying Heavy Loads (중량물 운반을 위한 에어쿠션 이송장비의 개발)

  • Yun, Dongwon;Park, Hee-Chang;Kim, Byung-In;Lee, Sung-Hwi;Jang, Seung-Ik;Hong, Ik-Pyo
    • Journal of Power System Engineering
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    • v.19 no.5
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    • pp.17-24
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    • 2015
  • In this paper, the development of an air cushion transporter has been studied. To do this, theoretical analysis is introduced to design the equipment and computational fluid dynamics is also conducted. Design of an air cushion transporter for heavy load carriage is completed and a prototype is manufactured. Through the analysis and experiment of the developed the prototype, it can be known that the developed transporter can levitate the load of about 1 ton at the applied pressure of 0.2 MPa and the maximum lifting height at this condition is 17mm.

Numerical Study on the Air-Cushion Unit for Transportation of Large-Sized Glass Plate

  • Jun, Hyun-Joo;Kim, Kwang-Sun;Im, Ik-Tae
    • Journal of the Semiconductor & Display Technology
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    • v.6 no.1
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    • pp.59-64
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    • 2007
  • Non-contact transportation of a large-sized glass plate using air cushion for the vertical sputtering system of liquid crystal display (LCD) panel was considered. The objective of the study was to design an air pad unit which was composed of multiple injection and exhaust holes and mass flow supplying pipe. The gas was injected through multiple small holes to maintain the force for levitating glass plate. After hitting the plate, the air was vented through exhaust holes. Complex flow field and resulting pressure distribution on the glass surface were numerically studied to design the air injection pad. The exhaust hole size was varied to obtain evenly distributed pressure distribution at fixed diameter of the injection hole. Considering the force for levitating glass plate, the diameter of the exhaust hole of 30 to 40 times of the gas injection hole was recommended.

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Numerical Study on the Air-Cushion Glass Transportation Unit for LCD Panels

  • Im Ik-Tae;Jeon Hyun-Joo;Kim Kwang-Sun
    • Journal of the Semiconductor & Display Technology
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    • v.5 no.1
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    • pp.27-31
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    • 2006
  • Non-contact transportation system using air cushion for the manufacturing of large-sized LCD panels was considered. Flow characteristics between air pad and glass plate was analyzed using computational fluid dynamics method to obtain optimized air pad configurations. Effects of the design variables such as hole arrays from which gas is injected, gas-feeding method into the gas supplying channels, and horizontal and vertical pitches of clusters of holes were studied. Optimized air pad unit gave evenly distributed pressure contour on the glass surface and well-suspended levitation height in the experiment.

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A Study on the Trade-off Analysis of Combat Weight for Conceptual design of a Landing Craft Air Cushion (공기부양상륙정의 개념설계를 위한 전투중량 대안분석 연구)

  • 이제동;신용석
    • Journal of the Korea Institute of Military Science and Technology
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    • v.3 no.1
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    • pp.66-75
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    • 2000
  • The purpose of this study is to develop and illustrate methods of applying trade-off techniques to landing craft air cushion design evaluation. The problem areas of concern are the application of quantitative analytical methods to conceptual design. The interrelationships between composite system measures and selected performance requirements(speed, cruising range, cargo etc.) are analyzed and the expressions for gross weight are developed as functions of performance parameters. Trade-offs of performance parameters in terms of weight are then calculated. The application of these results to evaluation of Require Operational Capabilities are illustrated.

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Development of an Air Cushion Vest (공기주입형 쿠션 베스트 개발)

  • Son, Sue-Min;Choi, Hei-Sun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.36 no.2
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    • pp.179-193
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    • 2012
  • The development of modern transportation technology has required many people in spaces (such as vehicle seats, airports, and train stations) for long periods. The public seats provided in these places are manufactured in a standard size; however, fatigue sets in if the seats are unsuitable for the person's physical size. For this reason, this study developed an air cushion vest that would enhance the comfort of vehicle seats. Passengers in vehicles, trains, airplanes, and buses were observed and surveyed to understand the demand for seat comfort. Our analysis found that the greatest source of discomfort was involuntary nodding of the head while asleep and discomfort around the waist area. For this reason, the air cushion vest was designed to support the head and the waist. The neck cushion of this vest was designed to strengthen head support to counter forward nodding because existing commercial neck cushions had no support for forward nodding. For the waist cushion, at lumbar and below-lumbar parts were chosen as the key parts to be supported, the cushion was designed to contain air at those parts. To cover the embedded waist cushion, the vest was designed to be long. The closure was constructed with zippers from the neck to waistline, and with invisible snaps from the waistline to the hemline so that the wearer could open them easily while seated. A subjective comfort evaluation was conducted to verify the effectiveness of the developed vest. In the test, the developed cushions received a better evaluation than cushions currently available on the market. The volume of the vest could be adjusted by the inflow and outflow of air. It was proven that the vest was effective in terms of comfort and portability. This shows that the developed vest could enhance passenger comfort while sitting on vehicle seats.