scholarly journals The regularities of resistance and flow in pipes and wide channels

2018 ◽  
Vol 193 ◽  
pp. 02034
Author(s):  
Ilya Bryansky ◽  
Yuliya Bryanskaya ◽  
Аleksandra Оstyakova
Keyword(s):  
Comparative Analysis ◽  
Velocity Profile ◽  
Hydraulic Resistance ◽  
Cross Section ◽  
Resistance Coefficient ◽  
Hydraulic Structures ◽  
Hydraulic Characteristics ◽  
Hydraulic Resistance Coefficient ◽  
Logarithmic Velocity Profile

The data of hydraulic characteristics of flow are required to be more accurate to increase reliability and accident-free work of water conducting systems and hydraulic structures. One of the problems in hydraulic calculations is the determination of friction loss that is associated with the distribution of velocities over the cross section of the flow. The article presents a comparative analysis of the regularities of velocity distribution based on the logarithmic velocity profile and hydraulic resistance in pipes and open channels. It is revealed that the Karman parameter is associated with the second turbulence constant and depend on the hydraulic resistance coefficient. The research showed that the behavior of the second turbulence constant in the velocity profile is determined mainly by the Karman parameter. The attached illustrations picture the dependence of logarithmic velocity profile parameters based on different values of the hydraulic resistance coefficient. The results of the calculations were compared to the experimental-based Nikuradze formulas for smooth and rough pipes.

scholarly journals The hydraulic resistance coefficient in the conditions of simultaneous effect of Re, Fr and Unknown node mfrac found in MathML fragment.$ {B \over h} $

2019 ◽  
Vol 97 ◽  
pp. 05031 ◽  
Author(s):  
George Volgin
Keyword(s):  
Hydraulic Resistance ◽  
Turbulent Flows ◽  
Functional Dependence ◽  
Fluid Motion ◽  
Integrated Approach ◽  
Resistance Coefficient ◽  
Hydraulic Structures ◽  
Turbulent Regime ◽  
Hydraulic Resistance Coefficient ◽  
The Impact

One of the most important tasks of engineering hydraulics is to determine the energy loss during the motion of the fluid flow. The study of the question of whether the patterns of hydraulic resistances are similar in a calm and turbulent flow is relevant in the design of hydraulic structures. In most cases, a turbulent regime of fluid motion is observed in various applications, but to date, the theory of turbulence is not considered complete. When designing hydraulic structures, inaccuracies in the existing calculation methods can lead to a decrease in the efficiency and reliability of the entire spillway structure as a whole. The need for an integrated approach to the analysis of the impact on the hydraulic resistance of various factors is noted (degree of spread $ \left( {{B \over h}} \right) $), the degree of turbulence (Re) and the degree of flow roughness (Fr)), which is not always provided by known dependencies and methods of calculation. On the basis of our own experimental data, a new formula for calculating the hydraulic resistance of turbulent flows in smooth channels was obtained. The functional dependence of the hydraulic resistance coefficient on the parameters $ \left( {{B \over h}} \right) $, Re and Fr is obtained.

Determination of hydraulic resistance of channels using spectral geometry methods

2021 ◽  
Author(s):  
Alex Baron
Keyword(s):  
Hydraulic Resistance ◽  
Cross Section ◽  
Dissipation Rate ◽  
Average Energy ◽  
Energy Dissipation Rate ◽  
High Accuracy ◽  
Spectral Geometry ◽  
Constant Cross Section ◽  
Theoretical Justification

Abstract In this paper, we propose a new method for calculation of hydraulic resistance of channels with constant cross-section. The method is based on the obtained estimates for the average energy dissipation rate in a turbulent flow. The first part of the paper is devoted to theoretical justification of the method. The second part is devoted to calculation of hydraulic resistance of various channels using the abovementioned method and comparison of these values with the known results. The proposed method allows for calculation of hydraulic resistance of various channels with sufficiently high accuracy and is based only on the information about the channel geometry.

scholarly journals Collecting of finely dispersed particles by means of a separator with the arc-shaped elements

2019 ◽  
Vol 126 ◽  
pp. 00007 ◽  
Author(s):  
Andrey V. Dmitriev ◽  
Vadim E. Zinurov ◽  
Oksana S. Dmitrieva
Keyword(s):  
Hydraulic Resistance ◽  
Flow Rate ◽  
Gas Flow ◽  
Reynolds Numbers ◽  
Resistance Coefficient ◽  
Dusty Gas ◽  
Gas Flow Rate ◽  
Hydraulic Resistance Coefficient ◽  
Purification Efficiency ◽  
Dispersed Particles

This paper includes the description of a separator, developed by the authors for the gas flow purification from the finely dispersed particles. The authors also studied the influence of the separator dimensions and the dusty gas flow rate on the degree of its purification from the finely dispersed particles, as well as on the change in the hydraulic resistance of this apparatus. This paper also shows that the main forces that make the greatest contribution to the purification of the gas flow from the finely dispersed particles are centrifugal and inertial. Moreover, the dependencies of the purification efficiency on the Stokes numbers are shown in this paper. The authors studied the change in the hydraulic resistance coefficient of this apparatus from the Reynolds numbers as well.

scholarly journals Hydraulic resistance accompanying waterjet cutting

Vestnik MGSU ◽  
2020 ◽  
pp. 399-408
Author(s):  
Lyudmila V. Volgina ◽  
Ivan A. Gusev
Keyword(s):  
Hydraulic Resistance ◽  
Two Phase Flow ◽  
Resistance Coefficient ◽  
Phase Flow ◽  
Hydraulic Systems ◽  
Two Phase ◽  
Pressure Losses ◽  
Hydraulic Resistance Coefficient ◽  
Complex Process ◽  
Physics Experiment

Introduction. Two-phase flow transmission is a complex process exposed to the influence of numerous factors. Its characteristics may depend on the physical properties of a flowing medium and on the properties of a pipeline, flow velocities, etc. A research into new types of hydraulic systems serves to identify the parameters that characterize the processes that accompany their transmission, especially if a multi-component flow is analyzed (a mix of water and abrasive particles). The mission of the research is to identify the value of hydraulic resistance coefficient in the course of transmission of a two-phase flow, or a mix of water and an abrasive. Materials and methods. A physics experiment, mathematical data processing methods, data description. Results. The co-authors have identified the hydraulic resistance coefficient value in the course of the mix transmission, as well as the parameters characterizing supplementary pressure losses in the course of the abrasive transmission. The experimental research enabled the co-authors to identify maximal water and mix application distances that reach 317 and 290 meters. Conclusions. The results, obtained by the co-authors, are the consequence of the pressure losses that occur in the course of mix transmission and the coefficients that characterize it. The flows considered in the article are used in the systems whose parameters are considerably different from those of traditional hydraulic engineering systems; therefore, any theoretical results obtained by the co-authors need experimental verification. Further, similar systems having different parameters must also be exposed to research to identify the relation between the pressure loss and the abrasive consumption rate and amount. The practical value of the research consists in the identification of maximal water and mix transmission and application distances providing that the operating parameters of the systems remain unchanged.

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