不同下垫面上近地层湍流的多尺度属性研究

A STUDY ON MULTI SCALE CHARACTERISTICS OF THE SURFACE-LAYER TURBULENCE ON DIFFERENT UNDERLYING SURFACE

文中利用统计和多尺度分析方法分析了几种复杂下垫面情况下的风、温湍流脉动观测资料 ,结果表明 :下垫面结构的差异明显地影响湍流量 ,如 :戈壁地区的热力作用明显大于雪面和城郊面 ,表现在湍流时间尺度上也明显地大于雪面和城郊面。但复杂下垫面下的湍谱在惯性区仍满足“- 23”次律 ;多尺度方法研究湍流 ,可以更简捷地分析湍流的多尺度结构及其在湍流输送中的作用。由此可看出 ,多尺度方法是发展湍流统计理论的一种有效工具。

The observational data of turbulent velocity, temperature fluctuation on several complex underlying surfaces are used to analyze the microstructure and transfer characteristics of turbulence near the surface by statistical method and multi scale analysis scheme. The results show that different underlying surface structures affect evidently turbulence, for example: Gobi underlying surface's thermal affection is more obvious than another regions. This causes turbulent time scale in Gobi to be very larger than those in another regions. However turbulence spectra on complex underlying surfaces in the inertial subrange conform to “-23”power law ; It is simple to analyze turbulent multi scale structures and their action on turbulent transfer with multi scale analysis method. It shows that multi scale method is a valid tool to develop turbulent statistical theory.