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在森林树冠上使用波纹研究火 - 大气相互作用
Ajinkya Desai1, Clément Guilloteau1, Warren E Heilman2
1Department of Civil and Environmental Engineering, University of California, Irvine, CA 92697 USA.
概括
野火会产生复杂的动荡. 这项研究使用波形分析来发现火灾引起的温度和流量模式的特征时间尺度,揭示了比正常更短的坡道持续时间和更高的斜率.
科学领域:
- 大气科学 大气科学
- 野地的火灾动力学 野地的火灾动力学
- 流研究 流研究
背景情况:
- 野火与大气的相互作用会产生复杂的,多层次的流.
- 这种流影响着火灾的传播,火柴的传输和烟雾的散发.
- 了解这些动态对于准确的火灾行为建模至关重要.
研究的目的:
- 调查风力驱动森林火灾期间温度和流的连贯模式的特征时间尺度.
- 用波束技术分析火如何影响流结构及其演变.
- 为改善野火和标量运输模型提供见解.
主要方法:
- 利用基于波纹的技术来分析塔式声波动力计的温度和速度测量.
- 在时间频率平面上检查能量密度,以确定流的时间尺度.
- 采用交叉波形连贯性分析来研究在树冠顶部附近的热量和动量流量事件.
主要成果:
- 确定了温度调节火灾的坡道-悬崖结构,其持续时间较短,斜坡比环境条件更.
- 观察到由火引起的热流事件连贯到1秒的时间段,与17秒以上的环境事件不同.
- 随着火灾前线的演变,在树冠顶部附近的流特征的记录变化,表明火焰影响和大气变化的变化.
结论:
- 波形分析揭示了火灾引起的流特征的独特时间尺度.
- 了解这些尺度是开发更可靠的野火行为和运输模型的关键.
- 该研究为多个尺度的火-大气相互作用动态提供了定量基础.
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