推移質輸砂率的冪率函數模型及其應用

Power Law Function Model of Bed Load Transport Rate and its Application

許曉陽(Xiao-Yang Xu) ； 張根廣(Gen-Guang Zhang) ； 周雙(Shuang Zhou)

《農業工程學報》 68卷4期 (2022/12) Pp. 80-90

https://doi.org/10.29974/JTAE.202212_68(4).0003

摘要

推移質輸砂率公式一般可轉化為無量綱輸砂強度和無量綱水流強度的冪率函數關係，但冪率函數的指數嚴格來說並不是一個常數，而是一個隨著推移質運動強度而異的變數。基於漸近線輔助擬合法，推導了能夠反映指數變化的推移質輸砂率冪率函數模型，該模型不包含泥砂臨界起動條件，兼顧了低、中及高強度的推移質輸砂率計算。以推移質輸砂率的冪率函數模型為基礎，構建了泥砂起動概率公式和陡坡推移質輸砂率公式。通過與實測資料和各經典公式的對比，表明本文所提公式均具有較高的計算精度和良好的適用性，可為工程實際應用提供可靠參考。

關鍵字

推移質輸砂率 ； 冪率函數 ； 變冪指數 ； 起動概率 ； 陡坡河道

並列摘要

The formula of bed load sediment transport rate can generally be transformed into the power function relationship between the dimensionless sediment transport intensity and the dimensionless water flow intensity. The exponent of power function is not a constant, but a variable that varies with the intensity of bedload movement. Based on the asymptote assisted fitting method, a power function model of bed load transport rate that can reflect the change of index n is derived. The power function model does not involve the critical starting condition of sediment Θ_c. The bed load transport rate can be calculated considering low, medium and high sediment transport intensity. Based on the power function model of bed load transport rate, the formula of sediment incipient probability and the formula of bed load transport rate on steep slopes are constructed. Through the comparison with the measured data and the classical formulas, it shows that the formulas in this paper have high calculation accuracy and good applicability, which can provide a reliable reference for the practical application of engineering.

並列關鍵字

Transport rate of bed load ； Power law ； Changing exponent ； Entrainment probability ； Steep channel

參考文獻

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