资源描述
徐州工程学院毕业设计 外文翻译 学生姓名 左林冬 学院名称 机电工程学院 专业名称 机械设计制造及其自动化 指导教师 陈凤腾 2011 年 05 月 27 日 on in on of as is a to is in a of a is of of on a) is (b) of or c) of to is of is A is of is at a a) of (b) an be of c) a .6 of 1 in of in of 15. of a is of is to of an on of as a on in of of of of et 6 by in to to in of et 7 in an It as of of a to a to As of of of et 8 on at of by a) of b) of of et 9 an of of as to on a of 500. on et 10 on A in of in to of of by k 1 to be to et 11 in a an of of of a of by at in a on of of up et 12 in in to of in a as as a of of be to in By of in be of a of be by a a as in et 13 a of in by of an k 1 on NG to of a a of a of of by a a a It of a on of in in of et 14 a) in (b) c) on of as in in on of It of to of et 15, 16 of a of of on of of to be be a As an iu et 15, 16, on of in (a) on of NG k 1 be to (b) of of on be (c) of be d) be a to of 2 F of If of a or of Pa 0 8C. of be by a K ), be as Po u u -P i n o u t is in a 14, 1720. It if is K ) be .4 so as to in of is a to in (a) is a of of a a a to is of is a of be of to a of of t be as P o u tP o u tP o u tP vP o u in a be K ou ou tK be to be to of In of of is to a as 1(a); 1(b) an of 21, 22. 1(a), AB C of ED is of CD E is to be = 998.2 kg/ =0s; of on of of a be as NG k 1 k ) in is to to he k) of 1) 6) 7), In of of is in of be by of by In Gk of to sk s1 k , of of of As a of it is to of to of of 2. r) of 10 1 r . r be of of up 5.3 as 2(a). to of a an r of be r .5 of or of of r . of up 6.7 as (c) d); of 3 .1 .0 of 10 1 It be 3 r .2 or be by or of a to of r .2 be by a r in In to r, a l ) to of E to of D. by ); on as of r) on of 10 4 4. r, on r is to be as a A be In a be of a 4, on l) at It of on of of 关于二 级 液压 节流锥阀 的低汽蚀研究 摘要 ： 汽蚀 对 于 液 压控制阀的性能和寿命有重要影响 ,如 引起 效率的降低 ,产生 强烈的噪音和振动。二级节流阀目前作为一种来减小 汽蚀 的装置被广泛用于液压安全阀和 节流阀。可以通过数值模拟的方法来研究介质在二级节流阀介质腔的压力分布。对两个节流阀的截面比和介质腔内的进出口压力产生的影响进行研究。仿真结果表明 ,(1)介质腔内的压力不是固定的 ,(b)介质腔最大和最小压力的位置都是固定的 ,不会随着通道面积比率或进出口压力而变化 ,(c)流过前面节流阀和流过二级节流阀的总压降的压降比值几乎不变。然后建立二级节流阀临界汽蚀指标 ,。通过该二级液压节流阀 得到设计的经验准则。对临界汽蚀指标和通道的两个截面比例之间的关联性进行实验研究。相关验证实验在一个定制的测试仪器中进行。 实验结果和模拟研究是一致的。进一步的分析表明 ,(a)大的反压力不仅可以提高抗汽蚀能力还可以改善二级液压节流阀的总负荷刚性、 (b)一个适当的通道面积比例有利于提高二级液压节流阀的抗汽蚀能力 (c)通道面积比例为 二级液压节流阀会有最好的抗汽蚀能力，而且产生汽蚀的风险最低。 关键词 :流体动力学仿真计算、汽蚀、负载刚度、通道面积比率、二级节流阀。 1 介绍 水压操作系统用原水 (纯自 来
展开阅读全文