查询词典 jet flow

The results show that the discharge and cooling stages of sparkjet were simulated by computational method. The instance energy input can produce the condition of high pressure and temperature in the actuator, which induce the forming of synthetic jet. With the increment of the input energy, the velocity of the synthetic jet could be increased to the supersonic state. Under the periodic energy input, the distribution of the sparkjet velocity on the nozzle is non-sinusoidal. And the discharge velocity of jet is much larger than the suction velocity of the flow from environment.

计算结果表明：采用本文的计算方法可以模拟出火花型激励器喷射、吸入的工作阶段；电火花瞬间能量的输入产生了腔体内的高温、高压环境，从而诱发合成射流的形成；当激励能量增加，激励器产生的合成射流速度增加，可达到超声速状态；周期性激励下，火花型合成喷喷口处的轴向平均速度随时间不是正弦分布，且喷射过程的最大速度要远远大于吸收过程的最大速度。

To understand the flow noise generation mechanism of pump jet propulsor, this paper calculates the flow field of a torpedo pump jet propulsor,analyzes the field structure, and then calculates its broadband noise with Proudman theory.

随着理论计算方法的逐步完善以及计算资源的增强，对流动噪声进行理论数值分析已逐渐可行并成为深入了解声源传播途径、噪声产生机理及噪声声级预报的重要手段之一。

Reynolds number of impingement, inclined jet angle, the ratio of the jet distance to the diameter of the jet hole and the relative curvature (the ratio of the diameter of jet hole to the diameter of concave surface) were changed to study the rules of flow structures varying with these parameters. At the same time, the developing and disappearing phenomena of the induced vortex were analyzed.

通过改变冲击雷诺数、冲击角度、相对冲击间距（冲击间距和冲击孔直径之比）以及相对曲率（冲击孔直径同凹面靶板直径之比）等参数，分析了受限空间中，斜向冲击曲率表面后产生的涡系结构及其发展和变化规律。

In chapter 1, an up to now synthetically evaluation is given on the research ways and conclusions about jet in cross-flow. Considering the shortage of previous research ways and techniques (the instantaneous flow field and vortices field can not be properly get), in addition to the deficiency of corresponding conclusion (mainly concentrate on the analysis of time-average but little on structures of flow and action of vortex), the research way and content is draft out in this part. Though PIV, the time-average, instantaneous flow field and vortices field can be get, that will unveil the coherent vortex and its course of generation, development and evolvement, with the assistance of K-ε model and Hybrid Finite Analytic Method , which will proof-test the experiment result and bring some complementary, more profound research about the 3-D characters can be done. Using some fundamental topological theory and principle on flow analysis, with anglicizing of vortex structure, a reasonable description is the topological characteristic of near field in JICF given.

首先在第一章中对横流中湍射流的以往研究方法和研究成果给予了综合的评述，针对横流中湍射流旋涡结构以往研究中研究方法的局限性（不能很好得到流动的瞬态流场及涡量场）和相应研究成果中存在的不足（大都集中在时均特性的分析，对流动的内部结构和旋涡的运动阐述很少），明确了本文的研究方法和研究内容：通过PIV流动测量显示技术得到流动的时均及瞬态流场、涡量场，来揭示横流中湍射流的时均、瞬态流场、涡量分布特性，和各种具有拟序结构性质的复杂涡系的产生、发展及演化过程；结合湍流k-ε双方程模型及相应的HFAM计算方法，对于实验进行相互验证和补充，从而更为充分地研究各种旋涡的三维特性；利用拓扑分析的一些基本原理及相关规则，依据对各种旋涡结构的分析，做出对射流近区流场拓扑性质的合理描述。

Based on analysis of the current state of the flow pattern modeling abroad and at home, explains the meaning of the mathematical simulation of the flows in the valve.(2) Comparing flow simulation data of jet pump with its experimental one, the feasibility and reliability of FLUENT used for flow simulation are proved.(3) Based on the characteristic of valves, the fluid field analysis of specific ring-spray type flow-adjustable is finished. The valve structure is optimized to meet the need, which makes it have such advantages:(1)smaller vortex area and faintish vortex intensity, so the vibration of vortex is controlled effectively;(2)the pressure is distributed more equality, the transition area is larger.

论文的主要内容包括：(1)简述了阀门研究的现状与发展，在分析与总结国内外流体流动模拟研究的基础上，探讨开展阀门内水流运动数值模拟的意义；(2)对特定型号的射流泵进行了内部流场的数值模拟研究，并与实验数据相比较，验证了应用Fluent进行数值模拟的可行性和可靠性；(3)针对调流阀的特点，对特大口径环喷式流量调节阀进行流场计算，其设计指导思想如下： 1、控制旋涡，减小旋涡区，减小涡的强度； 2、控制压力分布，使阀体受力更均匀，改善局部应力状态，提高阀门使用的安全性； 3、最小绝对压力高于水的汽化压力，不产生汽蚀。

A computer-aided local transient flow property measuring system was developed using a high speed CCD camera coupled with optical fibers in order to study the Gas-liquid-solid three-phase jet loop reactors. SnO2 crystal films were orientally deposited on the alkoxysilane molecule-coated hydroxyl glass substrates so as to prepare surface-marked particles as the tracers. An image analysis system was established to identify different phases. Stroboscopic photography was utilized to extend the measure range. The developed measuring and analysis system was capable of determining accurately the local transient flow property in a G-L-S jet loop reactor. Based on the above system, local transient flow properties of gas, liquid, and solid phase were measured and studied the influences of fluid property, operation and configuration parameters on the reactor.

中文摘要：以气液固三相喷射环流反应器为研究对象，将高速CCD和光纤束耦合制成局部瞬态流动特性微机数据采集及图象处理系统，利用MPS硅烷分子在带有羟基的玻璃基底上的自组装引导SnO2晶态膜层在功能化表面上进行沉积，以获得表面标记的示踪粒子，解决图象处理技术与相的识别的问题，利用频闪技术拓展了测量上限，得到可以准确测定气液固三相喷射环流反应器中局部瞬态流动特性的测试系统；采用上述测试技术进行喷射环流反应器中局部气相、液相与固相瞬态流动特性的实验研究，并考察物性参数、操作参数与结构参数的影响规律。

The flow features of a self-excited precessing jet,which was generated based on the wall attachment effect,were analyzed in the paper;and the large eddy simulation approach was used to numerically study the flow inside a precessing jet nozzle.

分析了基于流体附壁效应而自激产生的旋进射流的流动特征，采用大涡模拟方法研究了射流喷嘴内部的流场。

In operation, the downhole devices will be laid down with tubings which will move up and down using the operation machine. Since the injection head can rotate in the determined speed, the rotating flow, compared with the conventional stable axial flow, can prevent the sands from depositing in the horizontal annular and washing the screen. The jet from high-efficiency jet nozzle will wash the screen directly with concentrated hydro-power. The working fluid can be clean water, without damage to the formation.

作业时用油管下入该井下装置，利用作业机带动油管上下移动，由于喷头可按照既定速度旋转，返回流体在水平段由常规的平稳轴向流动变为旋转流动，既可实现对防砂管的全方位解堵，又能避免砂粒沉积；高效喷嘴产生的射流直接对着防砂管冲击，能量集中；工作介质为清水，不会对地层带来二次污染。

In operation, the downhole devices will be laid down with tubings which will move up and down using the operation machine. Since the injection head can rotate in the determined speed, the rotating flow, compared with the conventional stable axial flow, can prevent the sands from depositing in the horizontal annular and washing the screen. The jet form high-efficiency jet nozzle will wash the screen directly with concentrated hydro-power. The working fluid can be clean water, without damage to the formation.

作业时用油管下入该井下装置，利用作业机带动油管上下移动，由于喷头可按照既定速度旋转，返回流体在水平段由常规的平稳轴向流动变为旋转流动，既可实现对防砂管的全方位解堵，又能避免砂粒沉积；高效喷嘴产生的射流直接对着防砂管冲击，能量集中；工作介质为清水，不会对地层带来二次污染。

In order to investigate the flow characteristics of Isothermal jet into cross-flow for a safety injection inclined tube in the reactor cooling system, the numerical simulations were carried out at various velocity ratio between jet and main flow by using the commercial computational fluid dynamics software CFX.

针对核反应堆冷却剂系统中的主管道安注斜接管等温横向射流问题，应用计算流体力学商用软件CFX进行等温横向射流流动的数值模拟，得出了典型运行工况下的三维流场分布。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。