新月型沙丘演化行为的模拟实验研究

项目名称： 新月型沙丘演化行为的模拟实验研究

项目编号： No.11272252

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 王元

作者单位： 西安交通大学

项目金额： 80万元

中文摘要： 沙丘是自然界最常见的风沙地形和荒漠拓展的主要方式，是风沙物理学和地貌学的重要研究内容，其中新月沙丘因其独特结构和自组织演化特性而受到特别关注。但自然界沙丘演化过程过大的时空尺度对传统实地研究造成巨大困难。本项目在风洞环境中分别调谐气流和沙粒两相参数来改变风沙流饱和度，从而模拟逼近饱和状态的小尺度新月沙丘的演化过程。在此基础上发展单沙丘演化的微、宏观尺度行为及多维度宏观行为的同步测量技术,并通过对环境参数的控制来发展精确完整的沙丘演化实验；通过野外观测记录自然沙丘的阶段形态特征和局部演化过程。基于渐进相似理论，结合实验及观测结果发展沙丘演化动力模型及相似准则。此工作将对揭示迁移型风沙自组织结构的临界尺度机理和演化规律产生重要意义。

中文关键词： 新月沙丘；风洞实验；光学测量；粒子追踪测速；数值模拟

英文摘要： (限3000 Characters)：Dunes are commonly observed in natural world and play an important role in the desert expansion. It is also the hot topic in the aeolian sand physics and geomorphology. Much attention has been paid to the barchans because of their unique structure and self-organized evolution features. However, it is very difficult to study thoroughly the barchans in the field because the spatial and temporal scales of the evolution are very large. In this project, we propose a collection of novel methods to modulate the saturation rate of the aeolian sand flow to simulate the evolution of the small scale barchans in the wind tunnel. Further, the synchronous measuring system to study its microscopic and macroscopic behaviors is to be developed. And then the evolution of the barchans are thoroughly studied with controlled parameters in the wind tunnel. On the other hand, the morphological characteristics and evolution are investigated by field observations. At last, based on the results obtained by experiments and field observations, the dynamic model of the barchans evolution will be developed and the asymptotic similarity analysis will be applied to obtain the similitude criterias for the wind tunnel simulation of barchans. The achievements of this project will provide a fundemental understanding of the stru

英文关键词： Barchan dune；Wind tunnel experiment；Optical measurement；Particle tracking velocimetry；Numerical simulation