查询词典 cavitation

The CFD method was applied to calculate and simulate the form and action process of the cavitation at the representative character of the cavitation erosion on the surface of the hydraulic turbines.Some argumentation was presented that micro jet impacted the wall with a certain degree when bubble collapsed with the result that the maximal strain of the wall annularly distributed the local of the boundary touching the micro jet.Cavitation was gradual to develop regionally at the mode of chain reaction and di...

针对水轮机叶片表面气蚀的典型特征，利用CFD方法进行仿真计算，模拟气蚀形成和作用过程；根据模拟计算结果提出了新观点：空泡溃灭发生微射流以一定的倾角冲击壁面，壁面材料产生的最大应变在流束边界局部区域，呈环状分布；空泡气蚀在局部区域是渐进的，以"连锁反应"形式扩展，具有一定过流环境的分布特征；典型的冲蚀缺陷形貌是空泡气蚀在不同阶段的产物。

The Large eddy Simulation is used to simulate the flow field and cavitation on an Orifice Energy dissipator. The characteristics of cavitation was analyzed. The calculated and the measured pressure distribution and the cavitation were in agreement.

采用大涡模拟方法对消能孔板流场及空化现象进行了数值模拟，研究分析了消能孔板空化特性，计算所得的压力分布及空化特性与减压模型实验结果进行了比较，二者符合良好。

From the results obtained in the study, the following conclusions can be made:The methylene blue and spectrophotometer method can capture the free radicals generated successfully. This is an effective way to measuring the free radicals quantitatively in cavitation, moreover it is easy to fulfill.The intensity of cavitation increases with reduction in the cavitation number. But the different mechanism of various enhancive processes (chemical and physical processes) results in different effect by cavitation number.The effect of operating parameters, such as inlet pressure, temperature and time on cavitation indicate that optimum operating conditions exist at the cavitation enhancive effect is maximum.It is important to optimize the structure of hydrodynamic cavitation reactor for achieving a desired effect. A reasonable geometric parameter can promote the enhancive effect for a fixed hydrodynamic condition.Ventilating appropriate gas to cavitating flow can increase cavitational intensity and hence promote the enhancive effect of hydrodynamic cavitation.

研究结果表明：亚甲基蓝分光光度计法，能够成功地捕捉到水力空化产生的羟自由基，是定量检测空化自由基简便易行的有效方法；空化程度随空化数的减小而增强，但对于不同的强化过程，因其强化机理不同，故空化数对强化效应的影响也不同；水力空化系统的压力、温度及时间等操作参数对空化强化效应的影响规律表明：在适宜的操作条件下可产生最佳的空化强化效果；空化发生器结构的优化设计是保证空化强化效应的重要前提，在一定的水力学条件下，合理的结构尺寸可以增强空化作用效果：往水流中适量加入干扰气体能够提高空化强度，增强空化强化效果。

The cavitation erosion behavior of CrMnN ferri te-austenite duplex stainless steel in distilled water and 3%NaCl solution has b een investigated by using a magnetostrictive-induced cavitation facility.The fre e-corrosion potential and polarization curve under quiescent and cavitating cond ition have been measured by electrochemical technique.

利用磁致伸缩空蚀实验机研究了CrMnN双相不锈钢在3%NaCl溶液中的空蚀行为，采用电化学技术测量了静态和空蚀条件下的自腐蚀电位变化和动电位扫描极化曲线。

With a cavitating model established for N-S equations from cavitation theory, cavitation evolution on the surface of a hydrofoil is developed: incipience of cavity, cavity growing, reentrant flow appearing, cavity retracting, shedding and smaller broken cavities moving downwards with the main flow.

根据空化流原理，建立了基于N-S方程求解的空化模型，利用这个模型计算了空化在翼型表面的演化过程：初生、长大、形成回注水流、空穴回缩、减小、脱落，以及小空泡随主流向下游运动的现象。

Cavitation is the most distinct characteristic of the high-power low-frequency ultrasonic fields, and it is also regarded as the primary mechanism of ultrasonic cleaning. Nevertheless, the measurement question of the high-power low-frequency ultrasonic fields hasn't been resolved well, because of the incomplete cavitation theory and the complexity of cavitation fields. The universal acceptant standard measurement hasn't been found up to the present so that it is difficult to judge of the performance of ultrasonic cleaning machines scientifically.

大功率低频超声场最鲜明的特点就是空化，而空化也被认为是超声清洗的主要物理机制，但由于其理论研究尚不完善，加之空化声场的复杂性，使得至今大功率低频超声场的测量未得到很好的解决，尚未找到一种与清洗效果有确定关系的普遍适用的标准方法，使得在客观地评判清洗机优劣时很困难。

In order to research the mechanism and effect of hydrodynamic cavitational enhancement, find the basic rule which affected it. The work has been carried out as following.First, an effective equipment of hydrodynamic cavitition is built. Second, we find a new method to capture the free radicals, which is used to measure the amount of hydroxyl. And its correlation with the intensity of cavitation has been studied aims at analyzing the effect of various factors on the yield of hydroxyl, achieving the optimum hydrodynamic cavitation conditions. Then, hydrodynamic cavitation is used to the degradation of organic wastewaters containing rhodamine B, and sterilization of biologic wastewaters containing enterobacter aerogenes. Finally, numerical simulation based on computer fluid dynamic has been made for verifying the effect of hydrodynamic cavitation theoretically.

为了探求水力空化强化效应的机制和效果，寻求影响空化强化效应的基本规律，本论文就此开展了如下研究工作：设计建立实用有效的水力空化实验装置；建立空化自由基捕捉新方法，并以此定量检测水力空化羟自由基，研究空化羟自由基产量与空化强度的关系，研究各种因素对空化自由基产量的影响，以寻求最佳空化强化条件；在此基础上，进行了水力空化对含罗丹明B有机废水降解处理、对含产气肠杆菌生物污水杀菌处理研究，实验检验水力空化的强化效果；根据计算流体力学理论对空化流场进行数值模拟，从理论上验证水力空化的发生效果。

All countries scholar have been looking for new cavitation to replace the ultrasonic cavitation technique, the hydrodynamical technique have lower cost and equipment simpler characteristics than the light or particle cavitation , so it was valuable of

本文所做的主要工作及所取得结论： 1 设计并组装了一套水动力空化反应循环系统； 2 设计了3种不同型号(孔径分别为1毫米、2毫米、4毫米)的多孔板； 3 比较了不同板在不同条件下的空化效应强弱； 4 利用该装置对大肠杆菌菌液进行消毒杀菌的实验研究；结论：(1)在孔径较小时，空化效应更强

In this text,according to home and abroad scholars's study on design of sonochemical reactor and parameters of ultrasound cavitation, I designed the sonochemical reactor cohered with transducers on its side wall, and study cavitation field and ultrasound field distribution by changing power and frequency ,and made research in absorption of different power and frequency ultrasound traveling in water, and especialy study the cavitation with different sound intensity.

笔者综合国内外学者关于声化学反应器的设计思路，设计了侧壁黏结换能器清洗槽式声化学反应器，改变频率定性测量反应器中的声场和空化场分布，研究不同频率的超声在水中传播的吸收情况、声空化和声压或声强的关系以及一定频率的超声在水中的有效空化范围。

At first,the theory and the happening conditions of cavitation damage are presented,at the same time,the reasons of cavitation damage and the position where the cavitation damage usually takes place are analyzed in tunnel spillways.

首先介绍了空蚀破坏的原理以及发生空蚀破坏的条件，并分析了龙抬头式泄洪洞发生空蚀破坏的原因和易发生空蚀破坏的部位。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷