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

项目编号：CTS-0350414 PRINCIPAL调查员：Dietmar REMPFERINSTUTION：伊利诺伊理工学院污染物扩散的直接反问题的最佳解决方案本项目的总体目标是开发实用的方法来预测污染物在大气中的扩散扩散，并在检测到污染物后定位污染源。如果大气速度场作为时间和空间的函数都有一个完整的描述，这个问题就能以令人满意的方式得到解决。然而，大气流动几乎总是湍流的，这意味着流动中存在着大范围的长度和时间尺度。因此，如果一个人打算通过简单地将传感器放置在足以分辨重要的流动长度和时间尺度的规则网格上来测量这些速度场，你会发现将需要令人望而却步的数量的传感器。根据这些考虑，有必要对湍流流场进行描述，即(A)需要最少的信息量，以及(B)在时间上允许尽可能高的精度来跟踪污染物浓度随时间的演变。本征正交分解法(Lumley，1971)已经发展成为一种用最少的信息量来描述湍流流场的方法。与这种方法相关的技术似乎也很适合于实现上述第二个目标。在环境管理和政策领域，以及在国防防御潜在的生物和/或化学威胁领域，准确评估和预测资源有限的污染物扩散都是重要的。2001年9月世贸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。令人关切的主要领域之一是使用化学或生物制剂进行恐怖袭击的威胁，特别是在9·11事件后发生了几起涉及生物战制剂(炭疽孢子)的事件之后。为了防御这种攻击，重要的是有能力及时检测到这种攻击的发生，并尽可能准确地定位攻击的来源。我们项目的一个主要动机是开发使实现这些目标成为可能的技术和技术。

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.