This process repeats itself at the same frequency at which the engine is running and thus , if the exhaust pipe can be made to resonate at the operating rpm of the engine , this will improve the engine ' s efficiency 因此这重覆的自我进气压缩过程在相同频率的引擎运转下,如果排气管可使引擎的每分钟转数产生共振,那这将提升引擎的效能
This thesis also describes the numerical simulation of three - dimensional turbulent flow in super - low specific - speed impeller , points out the turbulence model and numerical solution for it , and gives the writer ' s view of the grid - generation 论文的另一部分工作是数值模拟极低比转数泵叶轮内部流动，提出了适合的湍流模型和数值解法，并对网格的划分提出了自己的看法。
The roto - jet pump is a new kind of very low specific speed pump which is developed in recent years . it is always used in carbin black , food production , chemical industry and deep well mining system to supply the steady outflow with low flux and high pressure 旋转喷射泵是近些年才发展起来的一种极低比转数泵，主要用在碳黑、食品、化工以及深井采矿系统中用以提供小流量高水头的稳定出流。
Hardware circuit adopts c8051f005 singlechip as key part , and uses integrated monolithic chip l297 and l298 to realize chopper drive of stepper motor . and achieves the control of the transfusion rate and quantum through controlling the rotate speed and number of the step motor by keyset 硬件电路采用c8051f005单片机作为控制核心,利用集成芯片l297和l298对步进电机实现斩波驱动,通过按键控制步进电机的转速和转数实现对输液速度和输液量控制。
The process affect factors of synthesizing the new fine material tricobalt tetraoxide particles were discussed , such as temperature , the solution ph , revolution of stirrer , maturing time , washing water times , drying condition , the color change of process , were discussed , its formation mechanism and structures were systematically studied and discussed , tested the fine particles , the xrd test showed that the peaks became wide 经试验获得均匀凝胶沉淀法新技术优化后的工艺参数为:反应温度控制为273 . 15k左右, ph值为9 . 0 - 9 . 5之间,搅拌转数为300转/分,陈化时间24hr以上,水洗去除杂质,按温度分步烘干。
In present thesis , the actual design theories and methods for super - low specific - speed pump are introduced first , including " the increased flowrate design method " , " the method of anti - hump on h ~ q characteristic curve " , " non - overload design method " , " the design method of complex impeller " and so on . according to these methods , 5 types of impeller have been designed 论文首先对极低比转数离心泵的现行设计理论和设计方法作了介绍，包括加大流量设计法、减小或消除扬程曲线驼峰的途径、无过载设计及复合叶轮设计法等，并按照这些方法设计了五种叶轮。
Thermal stress control system actually gather the real - time data of unit sets ， compute temperature fields ， stress fields and maximum dangerous stress by the math modal ， decide target and speedup rotation in every stage of startup process ， and justify automatically to realize auto control a serial of processes of turbine ， such as speedup ， warm - up ， connecting net ， load changing ， stop and unsteady condition etc ， and improve automatic level of the unit sets . turbine auto startup ( tas ) system can automatically evaluate steam turbine ' s startup and load changing process according to thermal stress of 热应力控制系统实际是对机组运行参数进行实时采集与监控，通过数学模型实时地计算高、中压缸转子的温度场、应力场分布，以及最危险热应力，以确定启动过程各阶段的目标转数及升速率，并进行自动调整，实现机组冲转、升速、暖机、并网、升负荷、停机以及异常工况下的自动控制，大大提高了机组的自动化水平。
“ we have looked to gain performance by increasing the peak revs , and improving areas like cylinder filling and combustion , ” explained denis chevrier , renault ' s head of trackside engine operations . “ in qualifying trim , we expect a gain of several tenths of a second and the final dyno tests before the grand prix will allow us to determine exactly how much additional performance is available during the race “我们看上去已经通过增加最大转数取得了成绩，并改善了像汽缸填塞和燃烧这样的区域”雷诺赛道引擎运作负责人丹尼斯-谢维瑞尔解释说， “在排位赛中，我们期待能获得零点几秒的时间，大奖赛前的最后测试会允许我们最终决定可以在正式比赛中有多少的附加表现。 ”
Comparing tow methods of efficency pre - estimation , it finds out the new method fit for super - low specific - speed pump . acoording to the study and comparison on efficency and reliability , the thesis points out merits and faults of the 5 types of impeller , and draws a conclusion that the complex impeller and partly blocked - flow - passage impeller are fit for the impellers of super - low specific - speed centrifugal pump 比较了泵效率预估的方法，提出了适合于极低比转数泵效率预估的新方法，并对其性能要求的效率和可靠性两方面进行了研究比较，指出了五种形式叶轮各自的优缺点，得到结论：复合叶轮和部分堵塞流道的一般叶轮适合作极低比转数泵叶轮。
