管式干燥气固两相流的相似性原理及耦合数值模拟

【作者】 沈选举；

【导师】 陈君若；

【作者基本信息】 昆明理工大学 ， 材料加工工程， 2005， 硕士

【摘要】 本文运用气固两相流理论、计算流体动力学和流动相似等方法,对高温管式膨胀系统的气固两相流动进行了分析和研究。 某企业已成功生产了应用于某卷烟厂2400kg/h的高温管道式膨胀设备,目前拟自主研制6400kg/h高温管道式膨胀设备及系列产品。前人根据研究问题的实际工况,对2400kg/h高温管式膨胀设备进行了数值模拟,并和2400kg/h高温管式膨胀设备的实测数据进行了比较。但是6400kg/h高温管道式膨胀设备在结构上不能采用传统类比放样的办法进行设计,必须借助于相似理论设计其结构。 高温管式膨胀系统内的湍流流场非常复杂,对其进行数值模拟非常必要,本文根据所研究对象工作的物理环境(热、流场),综合考虑气固两相流理论、计算流体动力学理论,确定其影响的主要因素,建立了数学模型和控制方程。应用ANSYS/FLOTRAN软件,利用相似理论根据2400kg/h的高温管道式膨胀设备的模型建立6400kg/h的高温管道式膨胀设备的数学模型,并利用反复试算分析得出的高温气体以及烟丝混合气体两种介质的物性参数,对其进行了有限元分析计算对高温管式膨胀系统的内流场进行了数值模拟与分析,得出内流场的温度、速度、压力及气固两相的分布,利用ANSYS软件强大的后处理功能从各个方面对数值计算结果进行分析,并和2400kg/h的高温管道式膨胀设备的模拟的结果进行了比较,验证其模型的合理性。在以上分析的基础上,还提出了多种结构形式的高温管式膨胀设备的几何模型,对它们进行分析和结果比较,得出较为理想的结构。 结果表明,本课题对高温管道式膨胀系统的多物理场耦合数值模拟基本能够真实地反映出高温管式膨胀设备对烟丝的整个处理过程,本文的理论研究方法、数值模拟计算方法是正确可靠的。 采用数值模拟技术对工程问题中的流动与传热过程进行计算分析是一种十分经济有效的方法。该研究成果为该产品的进一步开发设计提供了理论依据,同时为气固两相流动的研究提供了手段,还为数值模拟技术在该工程领域的实际应用和推广打下了基础。更多还原

【Abstract】 By using gas-solid particles two-phase flow theory and computational fluid dynamics method, dynamic behaviors of gas-solid particles two-phase flow about high temperature expansion canal are investigated and studied.A firm has produced successfully the high temperature expansion canal of 2400kg/h used in tobacco factory, it want to develop the high temperature expansion canal of 6400kg/h. The predecessor has simulated the high temperature expansion canal of 2400kg/h, but the form of the high temperature expansion canal of 6400kg/h isn’t magnifying according to the traditional method, so it need similitude theory to design its form.The turbulent flow of high temperature expansion canal is very complex process, so it needs numerical simulation. This paper ensures the dominant influence factor according to the work physical environment of the research object and considering the theory of gas-solid two-phase and the theory of computational fluid dynamic method. It also builds up the mathematical model and the control equation. It establishes the mathematical mode of high temperature expansion canal of 6400kg/h on the basis of design parameter of the high temperature expansion canal of 2400kg/h by similitude theory. Then the text obtains the physical property coefficient of high temperature gas and the mixture gas of tobacco refuses by examination calculating over and over. The paper analyses and calculates by finite element of FLOTRAN of ANSYS software. It obtains the distribution of temperature、 velocity、 stress and gas-solid two-phase of the whole three dimension model. By the powerful after-treatment of ANSYS software, this text analyses the result of the numerical calculation from every aspect and compares with the actual measured value about some parameters of the high temperature expansion canal of 2400kg/h and the result of the numerical calculation of the high temperature expansion canal of 2400kg/h. It verifies the reasonableness of the model. On the basis of above-mentioned analysis, it also brings up the geometry models for somehigh temperature expansion canals with different structural form. For the geometry models above-mentioned, this text analyses and compares the results too. Finally it concludes a better ideal structural form.The results show that numerical simulation about the high temperature expansion canal reflects concretely the whole disposal process of tobacco refuses within the high temperature expansion canal. The theory investigation method and numerical simulation that used in this paper are correct and reliable.It is a very economical and efficient method to calculate and analyze the fluid field and distribution of temperature for the issue of engineering. The results of the paper offer the theory reliance for the design and the further exploitation design of the product and a method for the investigation of gas-solid two-phase flows, at the same time it offers established foundation for the application and extend of the technology of numerical simulation in the field of engineering technology.更多还原