Refined dependences of power-law form for calculation of hydraulic resistance and velocity distribution

21st International Scientific Conference on Advanced in Civil Engineering "Construction - The Formation of Living Environment"

土木建筑工程

Borovkov, Valery^1 ; Bryanskaya, Julia^1 ; Ostyakova, Aleksandra^1,2

Moscow State University of Civil Engineering, Yaroslavskoye Shosse 26, Moscow

129337, Russia^1

Laboratory of the Dynamics of Channel Flows and Ice Heat, Water Problem Institute RAS, Gubkina str. 3, Moscow

119333, Russia^2

关键词: Ecological monitoring;    Ecological situation;    Emergency situation;    Engineering problems;    Fundamental research;    Hydraulic characteristic;    Hydraulic engineering;    Hydraulic resistances;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/365/4/042046/pdf
DOI  :  10.1088/1757-899X/365/4/042046

学科分类：土木及结构工程学

来源: IOP

【 摘 要 】

To solve the engineering problems of hydraulic engineering, water supply and sanitation, prevent emergency situations at hydraulic structures, regulate channel processes, efficient ecological monitoring of water bodies, and develop measures that exclude crisis ecological situations, more and more accurate estimates are required for the hydraulic characteristics of water flows. Inaccurate assumptions and approximate methods of integration can lead to significant errors that significantly affect the results of predicting flooding of riverine areas; this requires further refinement of the calculation methods. Until now, theoretical and experimental substantiations of the basic propositions of the theory of turbulence, hydraulic resistances, channel processes cannot be considered sufficiently complete. The compositions of problems associated with flows in wide channels, problems of turbulence, ax symmetric flows in smooth and rough pipes, are of scientific and practical interest. The article investigates the dependencies for the calculation of kinematic and dynamic flow characteristics in deformed and undeformable boundaries. New formulas are given for a refined description of the distribution of flow velocities and hydraulic resistance of turbulent flows in pipes and channels. Based on the known fundamental research, the calculation-theoretical methods are refined. The results obtained for flows in non-deformable channels can be useful for estimating not only flow in pipes, but also river flows in hard, undeformable boundaries and with minor channel deformations (in channels and rivers). For the first time, the analysis made it possible to obtain power-law approximations of the resistance laws for smooth and rough tubes and to establish the actual relationship between the exponents in the velocity profile and the law of resistance.