挟沙气流输沙率研究

Blown-Sand Transport Rate

从挟沙气流中反映风沙输移特征的两个代表性无量纲参数———输沙率参数和特征风速参数之间的关系入手 ,结合大量的实测输沙率资料 ,对各家形式各异的输沙率公式进行了分析和比较 ,发现了各家公式在结构上的统一性 ,指出了现行输沙率公式适用范围的局限性。研究表明 ,现有各家输沙率公式不能完全概括实测输沙率资料所反映的各类规律。为此 ,本文提出了适用范围较大、具有一般结构形式的输沙率公式。该公式可以概括目前实测输沙率资料反映的各类规律和各家输沙率公式。文中利用实测输沙率资料分析了一般结构形式的输沙率公式中各参数的变化特点 。

With the thread of two dimensionless parameters, (=gQ/ρU\+3\-*) and r(=U *t /U\-*) , systematic analysis was made based on previous measured data and comparison was given for eight representative formulas for aeolian mass flux. As a result, a general formulation structure was proposed, from which each of the previous formulas could be reproduced. In addition, all patterns, drawn from the measured results, in terms of ～r relation presenting the blown\|sand transport rate were well reflected, including the monotony\|increase pattern that was excluded from the existing formulas. Therefore, the good fit of any existing formula to some data but deviate from other data could be explained by the general formula. Four primary parameters should be determined for description of various patterns and existing formulas. Variation of the primary parameters was also discussed with the measured data, and the relevance of some parameters to grain size characteristics was presented.