【作者】 邓继军；

【导师】 袁新明；

【作者基本信息】 扬州大学 ， 水力学及河流动力学， 2010， 硕士

【摘要】 随着经济的发展,水资源日益匮乏且水资源分布不均匀,因此管道输水已经得到越来越多的应用。在输水管道中,泥沙的淤积问题是一个比较常见但又较难解决的问题。虽然有一些简单的工程措施来减轻这一问题,但目前最主要的还是靠人工清淤,这样无疑增加了运行成本、减少了运行时间。针对这一问题,设想开发一套利用三维壁面射流设施定期定时的进行管道中的清淤工作。基于此,本文对动水环境下三维壁面射流机理特性进行研究。文中从理论分析、模型试验及数值模拟三个方面对动水环境下的三维壁面射流的流速分布、发展规律及影响范围进行了研究,主要的研究内容有：1、总结了自由射流及静水环境下的三维壁面射流理论的成果,借鉴他们的研究方法,为动水环境下三维壁面射流的深入研究打下基础。2、利用模型试验,测量在一定的动水速度下两种不同壁面射流流速情况下的流速分布,得出对称中心平面和展向流动平面的流速分布都各自具有相似性,对称中心平面的最大流速随着三维壁面射流的发展呈衰减趋势。3、通过数值模拟,计算得出了3组动水环境各7种射流比总计21个工况的射流流场,通过与模型试验实测数据的对比,肯定了数值模拟计算的准确性。对数值模拟结果的分析得出：三维壁面射流的影响范围与射流比呈线性关系,随着射流比的增大而增大,同时随着动水速度的增大,影响范围的增大速率也逐渐增大。通过本文的研究,得出了动水环境下三维壁面射流的发展规律,并着重研究了射流比及动水速度对射流影响范围的影响。研究表明,三维壁面射流能较大的提高近壁区的流速,因此应用到实际管道清淤工作中有一定的可行性。更多还原

【Abstract】 Pipe line has been used widely for transporting water with the development of economics. In the water pipeline, sediment deposition is a relatively common but difficult problem. Although there are some simple engineering measures to solve this problem, but the main measure is desilting by artificial currently. This will increase the running cost and reduce the running time surely. To solve this problem, a facility using three-dimensional wall jet for dredging work of the pipeline on a regular basis is envisaged to develop. Based on this, the paper researched the mechanism and characteristics of the three-dimensional wall jet in dynamic water. The paper studied the distribution of velocity, the law of development and the sphere of influence through theoretical analysis, model test and numerical simulation. The main research content of this paper are as follows:1. The results of the theory of free jet and the three-dimensional wall jet in hydrostatic water is summarized. Drawing on the methods of their research, the foundation for the research of the hree-dimensional wall jet in dynamic water is laid.2. The distributions of velocity of two different wall jet velocity at a certain speed of hydrostatic water are measured by model test. The distributions of velocity of both symmetry middle plane and level development plane are obtained. They have similarity in each plane. The maximum velocity of symmetry middle plane shows the trend of attenuation with the development of three-dimensional wall jet.3. The flow fields of 3 groups with different dynamic water velocity are calculated by numerical simulation, each group contains 7 differtent jet ratios. There are 21 conditions totally. The computation results are consistent with the model test data. The analysis of the numerical simulation results obtained that the sphere of influence of the three-dimensional wall jet has a linear relationship with the jet ratio, it increases with the increase of the jet ratio. At the same time as the increasing speed of the flowing water, the increase rate of the sphere of influence is gradually increased.The development pattern of three-dimensional wall jet in dynamic water is obtained by the research of this paper. It focused on the impact to sphere of influence of jet ratio and the velocity of dynamic water. The results of the research show that three-dimensional wall jet can improve the velocity of water near the wall greatly, so it is possible to apply to the actual dredging work in the pipeline.更多还原