• 제목/요약/키워드: Aluminum Tube

검색결과 243건 처리시간 0.026초

흡음재의 음향특성 예측에 의한 밀폐계의 내부 소음저감 (Interior Noise Reduction of Enclosure Using Predicted Characteristics of Absorber)

  • 이기연;심현진;이정윤;오재응
    • 한국정밀공학회지
    • /
    • 제23권4호
    • /
    • pp.60-66
    • /
    • 2006
  • For the purpose of finding out the sound field characteristics in a rectangular cavity, analytical and experimental studies are performed with white noise input. Two-microphone impedance tube method is used to measure the impedances of foamed aluminum. Foamed aluminum is well known metallic porous material which has excellent properties of light weight and high absorbing performance. And predicted impedances of foamed aluminum are compared with measured impedances. The predicted acoustical parameters are applied to the theoretical analysis to predict sound pressure field in the cavity. The measured sound absorption effects are compared with the predicted values for both cases with and without foamed aluminum lining in the cavity of the rectangular enclosure.

석재 또는 외장타일 건식 알루미늄 트러스 설치공법의 시공에 관한 연구 (A study on the construction of stone or exterior tile unit aluminum truss method)

  • 이영래;홍성욱;도선붕;김상원;안용선
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2012년도 춘계 학술논문 발표대회
    • /
    • pp.219-220
    • /
    • 2012
  • Steel method compared with conventional aluminum truss construction materials as the biggest difference, aluminum truss method by using an aluminum material construction of the existing steel truss compared with the welding operation is omitted, as the air operations will be reduced by about 40% do not need skilled workers in the existing portion of each tube and cost 11,233 to 13,173 won/㎡ cheap it was found.

  • PDF

저체온 환자 치료에서 정맥주입 수액의 열손실을 막는 간단한 방법에 관한 고찰 (A Simple and Easy Method to Prevent Intravenous Fluid Heat Loss in Hypothermia)

  • 이선화;최윤희;이동훈
    • Journal of Trauma and Injury
    • /
    • 제26권4호
    • /
    • pp.255-260
    • /
    • 2013
  • Purpose: For the treat hypothermia patients, active warming might be needed. In most emergency departments, IV warm saline infusion is used for treatments. However, during IV warm saline infusion, heat loss from the warm saline may occur and aggravate hypothermia. Thus, in this study, we conducted an experiment on conserving heat loss from warm saline by using a simple method. Methods: Four insulation methods were used for this study. 1) wrapping the set tube for the administration of the IV fluid with a cotton bandage, 2) wrapping the set tube for the administration of the IV fluid with a cotton bandage with aluminum foil, 3) wrapping the warm saline bag and tube with a cotton bandage, and 4) wrapping the warm saline bag and tube with a cotton bandage with aluminum foil. Intravenous fluid was preheated to a temperature between $38-40^{\circ}C$. The temperatures of the saline bag temperature and the distal end of the IV administration set were measured every ten minutes for an hour. The infusion rate was 1000 cc/hr, and to obtain an accurate infusion rate, we used an infusion pump. Results: The mean initial temperature of the saline bag was $39.11^{\circ}C$. An hour later, the fluid temperature at the distal end of the fluid temperature ranged from $39.11^{\circ}C$ to $34.3^{\circ}C$. Without any insulation, the initial temperature of the pre-heated warm saline, $39^{\circ}$ had decreased to $34.8^{\circ}C$ after having been run through the 170-cm-long IV administration tube, and after 1-hour, the temperature was $29.63^{\circ}C$. As we expected, heat loss was prevented most by wrapping both the saline bag and the IV administration set with a cotton bandage and aluminum foil. Conclusion: Wrapping both the saline bag and the IV administration set with a cotton bandage and aluminum foil can prevent heat loss during IV infusion in Emergency departments.

알루미늄 중공 곡관제품의 열간 압출굽힘가공 (Hot Metal Extru-Bending Process for the Aluminum Curved Tube Product)

  • 박대윤;진인태
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2003년도 춘계학술대회논문집
    • /
    • pp.359-362
    • /
    • 2003
  • The bending phenomenon has been known to be occurred by the different of velocity at the die exit. The difference of velocity at the die exit section can be obtained by the different velocity of billets through the multi-hole container and by the cohesion of billet inside the porthole die chamber. The bending phenomenon can be controlled by the different hole diameter. The experiments using aluminium material for the curved tube product had been done. The results of the experiment show that the curved tube product can be formed by the extru-bending process without the defects such as the distortion of section and the thickness change of the wall of tube and the folding and wrinkling. It is known that the welding and extruding of each billet has done simultaneously although the curved tube is extruded with four billets.

  • PDF

튜브 하이드로포밍 공정의 성형한계 해석 (Analysis of forming limit in tube hydroforming process)

  • 김진;박춘달;김영석;이재용
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2004년도 춘계학술대회 논문집
    • /
    • pp.214-220
    • /
    • 2004
  • The automotive industry has recently shown a growing interest in tube hydroforming. Even though many structural parts in automotives have been produced from the cylindrical tubes, many failures - wrinkling, buckling, folding back, bursting and so on - are frequently experienced during the tube hydroforming process under improper forming conditions. In this paper, analytical studies are performed to determine the forming limits for the tube hydroforming process and demonstrate how the loading path influences the forming limit. The theoretical results for the forming limits of the wrinkling and bursting are then compared with the experimental results for an aluminum tube.

  • PDF

CAD/CAE를 이용한 알루미늄 7001 소재 파이프의 교정을 위한 롤러교정기의 설계 (Design of Tube/Pipe Straightener for Aluminum 7001 Pipes with CAD and CAE Methods)

  • 이형욱;허훈;허진혁
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2002년도 춘계학술대회 논문집
    • /
    • pp.25-28
    • /
    • 2002
  • This paper is concerned with the design of roller profiles in tube/pipe straightener with both methods of Computer Aided Design and Computer Aided Engineering. Design analysis is carried out from two point of view. The one is the research in the minimization of tube pitch which was very important factor in levelling process. In order to minimize tube pitch, profiles of the roller were calculated so that the contact region between roller and tube was maximized. The other is determination of an optimum amount of intermesh for the proper progress without a jam in levelling process. Generally the jamming trouble was casued by excessive amount of intermesh in levelling process. The optimum amount of intermesh was determined through the finite element analysis.

  • PDF

알루미늄 다채널 평판관내 R22, R410A, Propane의 흐름 응축 열전달 성능 비교 (Flow Condensation Heat Transfer Coefficients of R22, R410A and Propane in Aluminum Multi-Channel Tube)

  • 박기정;이기영;정동수
    • 설비공학논문집
    • /
    • 제17권7호
    • /
    • pp.649-658
    • /
    • 2005
  • Flow condensation heat transfer coefficients (HTCs) of R22, R410, Propane (R290) were measured inside a horizontal 9 hole aluminum multi-channel flat tube. The main test section in the refrigerant loop was made of a 0.53m long multi-channel flat tube of hydraulic diameter of 1.4 mm. Refrigerant was cooled by passing cold water through an annulus surrounding the test section. Data were obtained in qualities of $0.1\~0.9$ at mass flux of $200\~400kg/m^2s$ and heat flux of $7.3\~7.7kW/m^2$ at the saturation temperature of $40^{\circ}C$. All popular heat transfer correlations in single-phase subcooled liquid flow and flow condensation originally developed for large single tubes predicted the present data of the multi channel flat tube within $25\%$ deviation when effective heat transfer area was used in determining experimental data. This suggests that there is little change in flow characteristics and patterns when the tube diameter is reduced down to 1.4 mm diameter range. Hence, a modified correlation based on the present data was proposed which could be applied to small diameter tubes with effective heat transfer area. The correlation showed a mean deviation of less than $20\%$ for all data.

알루미늄 다채널 평판관내 R22 대체냉매의 흐름 응축 열전달 성능 비교 (Flow Condensation Heat Transfer Coefficients of R22 Alternative refrigerants in Aluminum Multi-Channel Tube)

  • 이기영;이민행;정동수
    • 대한설비공학회:학술대회논문집
    • /
    • 대한설비공학회 2005년도 동계학술발표대회 논문집
    • /
    • pp.249-255
    • /
    • 2005
  • Flow condensation heat transfer coefficients(HTCs) of R22, R4IO, Propane(R290) were measured inside a horizontal 9 hole aluminum multi-channel flat tube. The main test section in the refrigerant loop was made of a 0.53 m long multi-channel flat tube of hydraulic diameter of 1.4 mm. Refrigerant was cooled by passing cold water through an annulus surrounding the test section. Data were obtained in qualities of 0.1 ${\sim}$ 0.9 at mass flux of $200{\sim}400$ $kg/m^2s$ and heat flux of $7.3{\sim}7.7$ $kW/m^2$ at the saturation temperature of $4^{\circ}C$. All popular heat transfer correlations in single-phase subcooled liquid flow and flow condensation originally developed for large single tubes predicted the present data of the multi channel flat tube within 25% deviation when effective heat transfer area was used in determining experimental data. This suggests that there is little change in flow characteristics and patterns when the tube diameter is reduced down to 1.4 mm diameter range. Hence, a modified correlation based on the present data was proposed which could be applied to small diameter tubes with effective heat transfer area. The correlation showed a mean deviation of less than 20% for all data.

  • PDF

온간 하이드로포밍에 관한 유한요소해석 및 실험적 검증 (Finite Element Analysis and Experimental Confirmation of Warm Hydroforming Process)

  • 김봉준;박광수;최경호;문영훈
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2006년도 춘계학술대회 논문집
    • /
    • pp.277-280
    • /
    • 2006
  • The hydroformability of aluminum alloy sheets at elevated temperatures have been investigated in this study. It is necessary to analyze the variations of the mechanical properties that depend on the forming temperature and the heat conduction during warm hydroforming. Therefore, in this study a coupled simulation of plastic deformation and temperature distribution in the warm hydroforming process is performed and compared with experimental data. The multi-purpose code DEFORM-2D can handle this type of calculations but it takes high computation time if contact heat transfer between die, tube and pressure medium occurs. Experiments were conducted by high temperature tribometer(pin-on-disk) allowing measuring the friction coefficients of the aluminum alloys at several temperatures and these results are applied to the coupled simulation by which the optimal process parameters such as internal pressure and preset temperature on hydroformability can be determined. The comparison of the FE analysis with the experimental results has shown that hydroformability given by bulge height, and temperature distribution of the tube specimen make a little difference with the FE results but the trend predicted by simulation agrees well with experiments.

  • PDF

Effect of Inlet Direction on the Refrigerant Distribution in an Aluminum Flat-Tube Heat Exchanger

  • Kim, Nae-Hyun;Kim, Do-Young;Byun, Ho-Won;Choi, Yong-Min
    • International Journal of Air-Conditioning and Refrigeration
    • /
    • 제16권4호
    • /
    • pp.130-136
    • /
    • 2008
  • The refrigerant R-134a flow distributions are experimentally studied for a round header/ten flat tube test section simulating a brazed aluminum heat exchanger. Three different inlet orientations(parallel, normal, vertical) were investigated. Tests were conducted with downward flow for the mass flux from 70 to 130 $kg/m^2s$ and quality from 0.2 to 0.6. In the test section, tubes were flush-mounted with no protrusion into the header. It is shown that normal and vertical inlet yielded approximately similar flow distribution. At high mass fluxes or high qualities, however, slightly better results were obtained for normal inlet configuration. The flow distribution was worst for the parallel inlet configuration. Possible explanation is provided based on flow visualization results.