1) decayof turbulence
湍流衰减
2) decaying turbulence
衰变湍流
3) turbulent drag reduction
湍流减阻
1.
Studies(experimental study,theoretical analysis,numerical simulation and application tests in real systems)over around a half century since its discovery have provided much understanding on the turbulent drag reduction phenomenon and its value in applications.
添加剂湍流减阻是指在液体的管道湍流中添加少量的高分子聚合物或某种表面活性剂从而使湍流阻力大大降低的现象。
2.
To clarify the relation between turbulent drag reduction and self-excited vibration of flexible tubes, experiments were performed on the effects of turbulent drag reduction and the characters of self-excited vibration, by comparing the turbulent drag with, that in a rigid tube and by using a double-sleeve structure and a laser displacement sensor.
为弄清柔管自激振动的湍流减阻效果的初步机理,在通过实验确认柔管确有湍流减阻效果的基础上,采用双重管结构和激光测位仪,对柔管的自激振动特性及湍流减阻效果及其两者的关系进行了实验研究。
3.
Since then, turbulent drag reduction techniques have been more and more applied in engineering equipment of convection heat transfer.
此后,湍流减阻技术越来越多地应用在了各种工程设备中。
4) turbulence drag reduction
湍流减阻
1.
Since Toms found the turbulence drag reduction induced by the polymer,a lot of investigations have been done on the subject,but the mechanism for the drag reduction by the polymers still remains under debate.
自从 Toms 发现高分子湍流减阻效应之后,众多学者也纷纷开展了对其减阻机理的研究,但是一直都没有定论。
6) turbulence noise
湍流衰变<声>
补充资料：高分子减阻剂
| 高分子减阻剂 polymeric drag-reduction additives 具有减小流体流动阻力作用的高分子。在流体输送过程中加入此类高分子，能减少转展阻力，降低能耗。水相输送减阻剂研究开发较早，已研究了大量的水溶性高分子减阻剂，使用量仅几个ppm就可降低50％以上的阻力，有时高达80％。高分子减阻剂的结构及性质是：高分子具有无支链结构，分子量高，溶解性好等。聚环氧乙烷、聚丙烯酰胺是良好的水相减阻剂。油相减阻剂具有重要的实际意义，原油多以管道输送。由于粘度大、摩擦力高，输送中消耗也高，已应用的油相减阻剂有聚异丁烯、氢化聚异戊二烯、无规聚丙烯、丁二烯及苯乙烯的嵌段共聚物、乙烯与乙烯基酯的共聚物聚丙烯酰胺、乙烯和丙烯的共聚物等。如氢化聚异戊二烯，一般用量2～20ppm，即可使流速增加，摩擦损耗降低27％到50％。高分子减阻剂已广泛用于灌溉、泄洪、消防、原油输送等方面。其缺点是价格贵、易降解等。 |
说明：补充资料仅用于学习参考，请勿用于其它任何用途。
参考词条