Analytical solution for the flow velocity and water surface angle in drainage and sewer networks: case of pipes arranged in series

Author(s):  
Lotfi Zeghadnia ◽  
Lakhdar Djemili ◽  
Larbi Houichi
Author(s):  
Sara Mizar Formentin ◽  
Barbara Zanuttigh

This contribution presents a new procedure for the automatic identification of the individual overtopping events. The procedure is based on a zero-down-crossing analysis of the water-surface-elevation signals and, based on two threshold values, can be applied to any structure crest level, i.e. to emerged, zero-freeboard, over-washed and submerged conditions. The results of the procedure are characterized by a level of accuracy comparable to the human-supervised analysis of the wave signals. The procedure includes a second algorithm for the coupling of the overtopping events registered at two consecutive gauges. This coupling algorithm offers a series of original applications of practical relevance, a.o. the possibility to estimate the wave celerities, i.e. the velocities of propagation of the single waves, which could be used as an approximation of the flow velocity in shallow water and broken flow conditions.


2020 ◽  
Vol 162 ◽  
pp. 02002 ◽  
Author(s):  
Kirill E. Kazakov

This article is devoted to the statement and construction of analytical solution of the wearcontact problem for a rigid bush and elastic pipe with a coating in the case when the coating is nonuniform. The presence of nonuniformity leads us to the necessity of constructing a solution in a special form over special functions, since standard methods does not allow us to effectively take into account the complex properties of the coating. Analytical representation for contact stresses under the bush is presented in series with separate factor, which connect with complex properties of coating. This allows provide effective calculation even if these properties are described by rapidly changing or discontinuous functions. It is also shown that contact stresses will be negligible over time.


2007 ◽  
Vol 43 (6) ◽  
Author(s):  
Fredrik Huthoff ◽  
Denie C. M. Augustijn ◽  
Suzanne J. M. H. Hulscher

2005 ◽  
Vol 128 (1) ◽  
pp. 168-175 ◽  
Author(s):  
J. Y. Jang ◽  
M. M. Khonsari

This paper is devoted to a study of the enduring contact between granules of powder lubricants in an effort to better understand the flow characteristics of powder lubricants. Appropriate formulation of the governing equations is reported that can be used for prediction of the flow velocity, pseudo temperature, and volume fraction distribution of powders for a wide range of operating speeds. A set of parametric simulations and a limiting analytical solution is presented for predicting the behavior of a powder lubricant under low operating speeds when the enduring contact tends to dominate the kinetic regime. The limiting solution shows that below a certain sliding speed the volume fraction remains unchanged due to the effect of the enduring contact. It is also shown that below this limiting speed the enduring contact plays a major role and should not be neglected.


Author(s):  
Kevin D. Woods ◽  
Alfonso Ortega

This paper presents a method to determine the effective thermal conductivity and thermal diffusivity of a porous material, as well as the superficial flow velocity of fluid flowing through the porous matrix using a single probe transient moving line source method. The method transforms the transient analytical solution for a moving line source using differentiation to produce three independent equations to solve for the three unknowns. Empirical data are presented from a laboratory scale test apparatus for three test cases with known properties and flow rates to validate the method. The method is then applied to field data from a standing column well used in ground source heat pump systems to obtain the thermal and flow properties of the ground formation. The properties are inserted into the transient analytical solution for a moving line source and superimposed over the empirical data showing agreement between the model and the data. The method is more accurate than traditional methods for estimating thermal properties when flow conditions are present, and the implementation of the method does not require any additional thermal data.


1997 ◽  
Vol 35 (8) ◽  
pp. 57-67
Author(s):  
Horng-Guang Leu ◽  
C. F. Ouyang ◽  
Tze-Yi Pai

This study developed an analytical solution of reaeration rate coefficient (K2) and modified the equation of BOD removal in a shallow artificial open channel. A series of well-controlled batch tests were carried out to measure the K2 and BOD removal rate in the channel at different flow conditions. The results of these tests indicated that measured K2 within the developing zone of the laminar boundary layer is better described by the analytical solution of this study than by the five semi-empirical formulae mentioned in this paper. On the other hand, a resuspension-sedimentation coefficient, Rs, was added to the BOD removal equation to describe the variation in BOD due to varied flow conditions. Based on the results of the experimental data the following conclusions in the BOD removal process were reached. It was found that a direct correlation exists between the flow velocity to depth ratio (U/h) and the deoxygenation rate coefficient (K1), but there is an inverse correlation between U/h and Rs as well. This modified BOD removal equation can predict BOD removal rate at different travel times or known downstream distances in an open channel under varied flow conditions.


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