Engineering Research Equipment Grant: UV-Imaging Equipment

正在开发一种新的基于准分子激光的诊断方法， 应该产生瞬时二维温度和密度 高温介质中的场，例如发生在明火中或 内燃机. 由于该方法具有极好的时间 分辨率（10 ns），是分析湍流燃烧的理想选择。 它使用激光诱导荧光，但采用了一种新的方法， 消除了碰撞淬火的问题， LIF压力小于 0.01气氛 强大的窄带 紫外激光激发分子到预解离状态， 没有时间来消除碰撞。 是 提出了获得一个紫外像增强器和自扫描阵列 照相机以获得荧光的二维图像。 人能 然后照字面上的“快照”的密度分布， 单一选择量子态 通过比较两个这样的 在使用两个摄像机系统的状态下，温度分布可以是 用一次激光射击来计算。 激光技术特别有前途的组合 用于优化燃烧系统的检测器/计算机技术， 例如最小化污染物排放或最大化燃料经济性。 这里提出的方法将通过扩展 LIF到一个更有用的压力制度。

A new excimer-laser based diagnostic method is being developed that should yield instantaneous two-dimensional temperature and density fields in high-temperature media such as occur in open flames or in internal combustion engines. Because the method has excellent time resolution ( 10ns), it is ideal for analysis of turbulent burning. It uses laser induced fluorescence, but with a novel approach that eliminates the problem of collisional- quenching that normally limits LIF to pressures less than 0.01 atmosphere. A powerful narrow-band UV laser excites molecules to predissociating states that are so short-lived that there is no time for quenching collisions. It is proposed to acquire a UV image intensifier and a self scanned array camera to obtain two-dimensional images of the fluorescence. One can then literally take "snapshots" of the density distribution of a single selected quantum state. By comparing the densities of two such states using two camera systems, the temperature distribution can be calculated with a single laser shot. Laser techniques are particularly promising for combined detector/computer technologies for optimization of combustion system, minimizing pollutant emissions or maximizing fuel economy for example. The method proposed here will lead us in that direction by extending LIF to a more useful pressure regime.