SGER: Optimal Solution of the Direct and Inverse Problems of Contaminant Dispersion

摘要提案编号： CTS-0350414主要供应商：DIETMAR REMPFER机构： 伊利诺伊理工学院污染物扩散的正逆问题的最优解该项目的总体目标是开发实用的方法，用于预测污染物在大气中的扩散，以及一旦检测到污染物，则用于污染物源的定位。 如果能把大气层的速度场作为时间和空间的函数完整地描述出来，这个问题就能得到满意的解决。然而，大气流动几乎总是湍流的，这意味着流动中存在大范围的长度和时间尺度。因此，如果人们打算通过简单地将传感器放置在一些规则的网格上来测量这些速度场，该网格足够精细以解析流动的重要长度和时间尺度，人们发现将需要数量惊人的传感器。从这些考虑中得出，有必要获得湍流流场的描述，该描述（a）需要最少量的信息，并且（B）允许在时间上向后和向前跟踪污染物浓度随时间的演变时的最高可能精度。 本征正交分解法（Lumley，1971）是用最少的信息描述湍流场的一种方法。与这种方法相关的技术似乎也很适合实现上述第二个目标。 准确评估和预测有限资源中污染物的扩散在环境管理和政策领域以及在国家防御潜在生物和/或化学威胁领域都是重要的。 2001年9月世界贸易中心遭受恐怖袭击后，国民对潜在恐怖威胁的认识发生了重大变化。 特别是在9月11日事件之后发生了几起涉及生物战剂（炭疽孢子）的事件之后，人们主要关注的领域是使用化学或生物剂进行恐怖主义袭击的威胁。为了防御这种攻击，重要的是要有能力及时检测这种攻击的发生，并尽可能准确地定位攻击源。我们项目的主要动机是开发技术和技术，使实现这些目标成为可能。

ABSTRACTPROPOSAL NO.: CTS-0350414PRINCIPAL INVESTIGATORS: DIETMAR REMPFERINSTITUTION: ILLINOIS INSTITUTE OF TECHNOLOGY OPTIMAL SOLUTION OF THE DIRECT INVERSE PROBLEMS OF CONTAMINANT DISPERSION The general goal of this project is to develop practical methods for the prediction of the dispersive spread of contaminants in the atmosphere, and for the localization of the source of contaminants once they are detected. This problem can be solved in a satisfactory manner if a complete description of the velocity field of the atmosphere, both as a function of time and of space, is available. However, atmospheric flows are almost always turbulent, which means that large ranges of length and time scales are present in the flow. Thus, if one intends to measure these velocity fields by simply placing sensors on some regular grid that is fine enough to resolve the important length and time scales of the flow, one finds that a prohibitive number of sensors will be required. From these considerations it follows that it is necessary to obtain a description of the turbulent flow field that (a) requires a minimum amount of information, and (b) allows the highest possible accuracy in tracking, both backwards and forwards in time, the evolution of contaminant concentrations as a function of time. The method of Proper Orthogonal Decomposition (Lumley, 1971) has been developed as a means to describe turbulent flow fields using a minimal amount of information. The techniques associated with this method appear to be well suited also to achieve the second of the goals mentioned above. The accurate assessment and prediction of the dispersion of contaminants with a limited amount of resources is important both in the areas of environmental management and policy, as well as in the area of national defense against potential biological and/or chemical threats. After the terrorist attacks on the World Trade Center in September 2001, the national awareness of potential terrorist threats has undergone a significant change. Among prime areas of concern, in particular after the occurrence of several incidents involving agents of biological warfare (Anthrax spores) in the wake of the September 11 events, is the threat of terrorist attacks using chemical or biological agents. In order to defend against such attacks, it is important to have the capability to detect the occurrence of such an attack in a timely manner, and to locate the source of the attack as accurately as possible. A prime motivation of our project is the development of technologies and techniques that make it possible to achieve these goals.