Control of Flow and Mixing in Environmental Flows

A new class of methods is presented for the control of environmental flows. The primary objective is the identification and containment of chemical spills in infrastructure systems. The approach is based on real-time information provided by solid-state microsensors installed at appropriate locations and capable of monitoring instantaneous changes in the concentration of several species in solution or suspension. The approach also utilizes concurrent flow and transport data provided by a simulation model based on continuous simulation of the system. Once an environmental event requiring control action is detected by the sensors, the model provides optimal directions to pre-installed actuators capable of modifying the flow conditions in the flow domain. The technique requires assimilation of data from the sensors to steer the model, so the error between its present state and sensor measurements is minimized. The model also performs prediction simulations to determine the optimum set of actuator commands necessary to control the chemical plumes. The microsensors are constructed by combining custom electronic circuits with polymeric films. Several new approaches are tested at the interface between solid state technology and chemistry resulting in reliable and inexpensive sensor arrays. The new methods are tested in a variety of laboratory and large scale applications, and recommendations are made for the identifiability and controllability of general environmental flows.