Effects of Working Fluid,Tubeside Enhancement and Bundle Depth on the Optimized Fin Geometry of a Horizontal Condenser Tube

A theoretical study has been made to optimize the fin geometry of a horizontal finned tube which is to be usedfor condensers that handle the vapor load of a liquid phase change cooling module.Systematic numerical calcu-lations of the vapor to coolant heat transfer have been performed for parametric values of fin height,fin spacing,vertical bundle depth and tubeside heat transfer coefficient.Three dielectric fluids (R-113,FC-72,and FC-87)at atmospheric pressure were selected as the working fluids.For a single tube with optimized fin geometry,theaverage heat flux increased in the order of FC-87,R-113 and FC-72.Both the optimum fin height and optimumfin spacing increased with increasing vertical bundle depth.     

运用现代CFD方法设计高效率的汽轮机

论述了运用现代计算流体动力学(ComputationalFluidDynamics,CFD)技术设计高效率汽轮机的方法,典型应用的实例有全三维叶片级流场、叶片汽封和排汽蜗壳计算。计算结果和实际是相符的。进一步对结构性单元和非结构单元程序的计算结果进行了比较,已证明,非结构单元CFD程序用于复杂形状的流场计算时,结果与实际相当一致,并具有独特的功能。     

ShortCut Clipper剪钳

世界上第一款专为男性设计的弧形剪钳ShortCutClipper，创新叶片弯曲技术和革命性的可调式刷状设计，使男性能够准确、方便地自行理发。     

905mm末级叶片应力腐蚀和腐蚀疲劳研究

本文研究了引进型300MW汽轮机905mm末级叶片材料在80℃、22％氯化钠介质中的应力腐蚀开裂行为;测定了材料在空气,蒸馏水和80℃、22％氯化钠介质中不同平均应力时的条件疲劳极限。结果表明,在上述介质条件下,905mm末级叶片材料的应力腐蚀敏感性和腐蚀疲劳强度与869mm末级叶片材料相近。     

定向凝固空心叶片制壳工艺的改进

分析了在先进发动机定向凝固空心叶片熔模精密铸造生产中出现两种缺陷的性质和产生原因，从壳型制造工艺方面提出了改进措施，提高了叶片合格率。