• Title, Summary, Keyword: CAE Analysis

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Shape Optimization of Three-Way Reversing Valve for Cavitation Reduction (3 방향 절환밸브의 공동현상 저감을 위한 형상최적화)

  • Lee, Myeong Gon;Lim, Cha Suk;Han, Seung Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.11
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    • pp.1123-1129
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    • 2015
  • A pair of two-way valves typically is used in automotive washing machines, where the water flow direction is frequently reversed and highly pressurized clean water is sprayed to remove the oil and dirt remaining on machined engine and transmission blocks. Although this valve system has been widely used because of its competitive price, its application is sometimes restricted by surging effects, such as pressure ripples occurring in rapid changes in water flow caused by inaccurate valve control. As an alternative, one three-way reversing valve can replace the valve system because it provides rapid and accurate changes to the water flow direction without any precise control device. However, a cavitation effect occurs because of the complicated bottom plug shape of the valve. In this study, the cavitation index and percent of cavitation (POC) were introduced to numerically evaluate fluid flows via computational fluid dynamics (CFD) analysis. To reduce the cavitation effect generated by the bottom plug, the optimal shape design was carried out through a parametric study, in which a simple computer-aided engineering (CAE) model was applied to avoid time-consuming CFD analysis and difficulties in achieving convergence. The optimal shape design process using full factorial design of experiments (DOEs) and an artificial neural network meta-model yielded the optimal waist and tail length of the bottom plug with a POC value of less than 30%, which meets the requirement of no cavitation occurrence. The optimal waist length, tail length and POC value were found to 6.42 mm, 6.96 mm and 27%, respectively.

Effect of Extracts produced from Gardenia jasminoides Seed Using Different Types of Solvents on Nitrogen Oxide Scavenging Activities and Lipid Peroxidation Inhibition (치자(Gardenia jasminoides Ellis) 씨 추출물의 질소산화물 소거능 및 지질과산화 저해능에 관한 연구)

  • Jin, Dong-Hyeok;Oh, Da-Young;Lee, Young-Geun;Kim, Han-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.34 no.1
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    • pp.91-100
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    • 2017
  • The object of this study was to measure the bioactivity and antioxidant activity of seed from Gardenia jasminoides Ellis fructus (GJE). GJE seeds were performed the extraction of them by chloroform:methanol (CM, 2:1, v/v), 70% ethanol and n-butanol. Sequentially, total phenol content, nitrogen oxide scavenging activity, antioxidant activity and lipid peroxidation inhibition activity of the extracts were investigated. Solvent extract bioactivity of increasing concentrations (0.2, 0.4, 0.6 mg/mL) were significantly increased (p<0.05). GJE seed extracts showed lower activity than positive control (ascorbic acid, BHA, trolox). The highest concentration of CM extracts was obtained in the same manner as the results of analysis of the total phenol contents of the GJE seed, and 70% ethanol extract showed the highest activity of reducing power. The water soluble carotenoids crocin and flavonoid were effective. As a result of this experiment. the seeds of GJE showed excellent antioxidant, and lipid peroxidation inhibitory properties.

Immersive Visualization of Casting Solidification by Mapping Geometric Model to Reconstructed Model of Numerical Simulation Result (주물 응고 수치해석 복원모델의 설계모델 매핑을 통한 몰입형 가시화)

  • Park, Ji-Young;Suh, Ji-Hyun;Kim, Sung-Hee;Rhee, Seon-Min;Kim, Myoung-Hee
    • The KIPS Transactions:PartA
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    • v.15A no.3
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    • pp.141-149
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    • 2008
  • In this research we present a novel method which combines and visualizes the design model and the FDM-based simulation result of solidification. Moreover we employ VR displays and visualize stereoscopic images to provide an effective analysis environment. First we reconstruct the solidification simulation result to a rectangular mesh model using a conventional simulation software. Then each point color of the reconstructed model represents a temperature value of its position. Next we map the two models by finding the nearest point of the reconstructed model for each point of the design model and then assign the point color of the design model as that of the reconstructed model. Before this mapping we apply mesh subdivision because the design model is composed of minimum number of points and that makes the point distribution of the design model not uniform compared with the reconstructed model. In this process the original shape is preserved in the manner that points are added to the mesh edge which length is longer than a predefined threshold value. The implemented system visualizes the solidification simulation data on the design model, which allows the user to understand the object geometry precisely. The immersive and realistic working environment constructed with use of VR display can support the user to discover the defect occurrence faster and more effectively.

Physicochemical Characteristics and Antioxidant activities of Sikhye Made with Pigmented Rice (유색미로 제조한 식혜의 이화학적 특성 및 항산화 활성에 관한 연구)

  • Yang, Ji-won;Kim, Young Eon;Lee, Kyung Hee
    • Journal of the East Asian Society of Dietary Life
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    • v.25 no.5
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    • pp.830-841
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    • 2015
  • This study compared the physicochemical characteristics, proximate composition, taste compound and antioxidant properties of Sikhye prepared with pigmented rice. Proximate composition showed a significant difference depending on the type of pigmented rice except crude fat contents and pH, color was a significant difference depending on the type of pigmented rice. The highest brix degree was $15.07^{\circ}Brix$ in red and black rice Sikhye. Each highest value of reducing sugar and free sugar content showed milled rice and brown rice Sikhye. Titratable acidity and total acidity of the pigmented rice Sikhye were highest for black rice Sikhye, free sugar content were highest for green rice Sikhye. Analysis of their relative antioxidative properties indicated that black rice Sikhye had the highest total polyphenol, flavonoid, and anthocyanin content, the highest levels of DPPH radical scavenging ability, and the highest level of reducing power and ferric reducing ability of plasma scores. Principal component analysis suggested that black rice Sikhye had a strong association with antioxidant properties, brown and red rice Sikhye had the strongest association with the sweetness and unique flavor.

Evaluation of Lipid Peroxidation Inhibition and Nitrogen Oxide Scavenging Activity from Peel of Gardenia jasminoides Ellis Fructus Extracted by Various Solvents (치자(Gardenia jasminoides Ellis fructus) 껍질 용매 별 추출물의 지질과산화 저해 및 질소산화물 소거능)

  • Jin, Dong-Hyeok;Oh, Da-Young;Chung, Hun-Sik;Lee, Young-Guen;Seong, Jong-Hwan;Kim, Han-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.34 no.2
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    • pp.244-253
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    • 2017
  • The aim of this study was to investigate the bioactivity and antioxidant activity of peel from Gardenia jasminoides Ellis fructus (GJE). We were separated into GJE peel. After that, we determined anthocyanin. GJE peel were extracted by 70% methanol, distilled water (DW) and ethyl acetate (EA) three solvents. To investigate by the solvent extract of total phenol content and value as a functional food ingredient of GJE peel through nitrogen oxide scavenging activity, antioxidant activity, reducing power and lipid peroxidation inhibition were performed. Solvent extract bioactivity of increasing concentrations (0.2, 0.4, 0.6 mg/mL) were significantly increased (p<0.05). GJE peel extracts showed lower activity than positive control (ascorbic acid, BHA, trolox). The total phenol contents of GJE peel extracts were highest in EA extract. However, the order of total phenol content of the solvent in the GJE peel and the results of analysis of various physiological activities were inconsistent. Considering the extraction yield and various physiological activities, it is expected to be effective when extracted from 70% methanol and DW extract. The results suggest that GJE peel is highly expected to be useful as a functional foods and natural antioxidant.