Pub Date : 2020-02-21DOI: 10.37394/232013.2020.15.5
Rafi M. Qasim, Ihsan A. Abdulhussein, K. Al-Asadi
Composite hydraulic structure is widely used in irrigation system which consists of two parts. The first part is responsible for overflow regime and is represented by a weir, whereas the second part is responsible for underflow regime and is represented by a gate. Both elements play significant role to control, measured, and divert the flow. So it dominates the hydraulic regimes of open channel or river with high responsibility and accuracy. The target of this study is to investigate the effect of the composite hydraulic structure installation at various inclination angles (from 45-135 degree) with the flume bed, which is horizontal, and adopt the normal position of composite device ( angle equal to 90 degree) as guide in discussion with various angles. Several experimental works were carried out in hydraulic laboratory flume at the Basrah Engineering Technical College under free flow condition with various geometrical dimensions of combined rectangular weir and rectangular gate in order to investigate the effect of inclination angle on major flow factors such as actual discharge, discharge coefficient, depth of water in downstream zone of flume, cross sectional area of flow that cross or pass the weir and gate respectively. Also, this study mentions the percentage of increase in discharge coefficient and variation in actual discharge, discharge coefficient and Reynolds Number with cross sectional area of flow that cross the gate.
{"title":"Experimental Study of Composite Inclined Weir – Gate Hydraulic Structure","authors":"Rafi M. Qasim, Ihsan A. Abdulhussein, K. Al-Asadi","doi":"10.37394/232013.2020.15.5","DOIUrl":"https://doi.org/10.37394/232013.2020.15.5","url":null,"abstract":"Composite hydraulic structure is widely used in irrigation system which consists of two parts. The first part is responsible for overflow regime and is represented by a weir, whereas the second part is responsible for underflow regime and is represented by a gate. Both elements play significant role to control, measured, and divert the flow. So it dominates the hydraulic regimes of open channel or river with high responsibility and accuracy. The target of this study is to investigate the effect of the composite hydraulic structure installation at various inclination angles (from 45-135 degree) with the flume bed, which is horizontal, and adopt the normal position of composite device ( angle equal to 90 degree) as guide in discussion with various angles. Several experimental works were carried out in hydraulic laboratory flume at the Basrah Engineering Technical College under free flow condition with various geometrical dimensions of combined rectangular weir and rectangular gate in order to investigate the effect of inclination angle on major flow factors such as actual discharge, discharge coefficient, depth of water in downstream zone of flume, cross sectional area of flow that cross or pass the weir and gate respectively. Also, this study mentions the percentage of increase in discharge coefficient and variation in actual discharge, discharge coefficient and Reynolds Number with cross sectional area of flow that cross the gate.","PeriodicalId":39418,"journal":{"name":"WSEAS Transactions on Fluid Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48728744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-17DOI: 10.37394/232012.2020.15.1
D. Saha, S. Sengupta
A theoretical study is made to investigate heat and mass transfer analysis on the single phase flow of an electrically conducting, Al2O3-Water nanofluid over a linearly stretching sheet in presence of Soret and Dufour effects. An applied magnetic field is considered normal to the flow, while the effect of induced magnetic field got neglected for small magnetic Reynolds number’s value of the flow field relative to the applied field. Since voltage difference at the lateral ends of the sheet is very small, the influence of the electric field is thus omitted. The governing equations representing the physical model of the fluid flow is solved by means of DTM-Padé approximations. The acquired results show that an increase in the Soret number (Dufour number) decreases (increases) the temperature profiles but increases (decreases) the concentration profiles. The axial velocity profiles found decreasing with increasing values of the magnetic parameter. Both chemical reaction and thermal radiation parameters maximize the temperature profiles whereas a reverse phenomenon is seen on concentration profiles. The obtained tables show that increasing nanoparticle volume fraction escalates skin-friction coefficient, Nusselt number and Sherwood number whereas an increase in Richardson number decreases the Nusselt number but increases the Sherwood number.
{"title":"Dual DTM-Padé approximations on free convection MHD mass transfer flow of nanofluid through a stretching sheet in presence of Soret and Dufour Phenomena","authors":"D. Saha, S. Sengupta","doi":"10.37394/232012.2020.15.1","DOIUrl":"https://doi.org/10.37394/232012.2020.15.1","url":null,"abstract":"A theoretical study is made to investigate heat and mass transfer analysis on the single phase flow of an electrically conducting, Al2O3-Water nanofluid over a linearly stretching sheet in presence of Soret and Dufour effects. An applied magnetic field is considered normal to the flow, while the effect of induced magnetic field got neglected for small magnetic Reynolds number’s value of the flow field relative to the applied field. Since voltage difference at the lateral ends of the sheet is very small, the influence of the electric field is thus omitted. The governing equations representing the physical model of the fluid flow is solved by means of DTM-Padé approximations. The acquired results show that an increase in the Soret number (Dufour number) decreases (increases) the temperature profiles but increases (decreases) the concentration profiles. The axial velocity profiles found decreasing with increasing values of the magnetic parameter. Both chemical reaction and thermal radiation parameters maximize the temperature profiles whereas a reverse phenomenon is seen on concentration profiles. The obtained tables show that increasing nanoparticle volume fraction escalates skin-friction coefficient, Nusselt number and Sherwood number whereas an increase in Richardson number decreases the Nusselt number but increases the Sherwood number.","PeriodicalId":39418,"journal":{"name":"WSEAS Transactions on Fluid Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44438103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-12DOI: 10.37394/232013.2020.15.1
G. Cannata, L. Barsi, M. Tamburrino
A numerical model that solves two-phase flow motion equations to reproduce turbidity currents that occur in reservoirs, is proposed. Three formalizations of the two-phase flow motion equations are presented: the first one can be adopted for high concentration values; the second one is valid under the hypothesis of diluted concentrations; the third one is based on the assumption that the particles are in translational equilibrium with the fluid flow. The proposed numerical model solves the latter formalization of two-phase flow motion equations, in order to simulate turbidity currents. The motion equations are presented in an integral form in time-dependent curvilinear coordinates, with the vertical coordinate that varies in order to follow the free surface movements. The proposed numerical model is validated against experimental data and is applied to a practical engineering case study of a reservoir, in order to evaluate the possibility of the formation of turbidity currents.
{"title":"A 3D Numerical Model for Turbidity Currents","authors":"G. Cannata, L. Barsi, M. Tamburrino","doi":"10.37394/232013.2020.15.1","DOIUrl":"https://doi.org/10.37394/232013.2020.15.1","url":null,"abstract":"A numerical model that solves two-phase flow motion equations to reproduce turbidity currents that occur in reservoirs, is proposed. Three formalizations of the two-phase flow motion equations are presented: the first one can be adopted for high concentration values; the second one is valid under the hypothesis of diluted concentrations; the third one is based on the assumption that the particles are in translational equilibrium with the fluid flow. The proposed numerical model solves the latter formalization of two-phase flow motion equations, in order to simulate turbidity currents. The motion equations are presented in an integral form in time-dependent curvilinear coordinates, with the vertical coordinate that varies in order to follow the free surface movements. The proposed numerical model is validated against experimental data and is applied to a practical engineering case study of a reservoir, in order to evaluate the possibility of the formation of turbidity currents.","PeriodicalId":39418,"journal":{"name":"WSEAS Transactions on Fluid Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43856811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-02-12DOI: 10.37394/232013.2020.15.2
E. Prozorova
There are many experimental facts that currently cannot be described theoretically. A possible reason is bad mathematical models and algorithms for calculation, despite the many works in this area of research. The aim of this work is to clarificate the mathematical models of describing for rarefied gas and continuous mechanics and to study the errors that arise when we describe a rarefied gas through distribution function. Writing physical values conservation laws via delta functions, the same classical definition of physical values are obtained as in classical mechanics. Usually the derivation of conservation laws is based using the Ostrogradsky-Gauss theorem for a fixed volume without moving. The theorem is a consequence of the application of the integration in parts at the spatial case. In reality, in mechanics and physics gas and liquid move and not only along a forward path, but also rotate. Discarding the out of integral term means ignoring the velocity circulation over the surface of the selected volume. When taking into account the motion of a gas, this term is difficult to introduce into the differential equation. Therefore, to account for all components of the motion, it is proposed to use an integral formulation. Next question is the role of the discreteness of the description of the medium in the kinetic theory and the interaction of the discreteness and "continuity" of the media. The question of the relationship between the discreteness of a medium and its description with the help of continuum mechanics arises due to the fact that the distances between molecules in a rarefied gas are finite, the times between collisions are finite, but on definition under calculating derivatives on time and space we deal with infinitely small values. We investigate it
{"title":"The Effect of Angular Momentum and Ostrogradsky-Gauss Theorem in the Equations of Mechanics","authors":"E. Prozorova","doi":"10.37394/232013.2020.15.2","DOIUrl":"https://doi.org/10.37394/232013.2020.15.2","url":null,"abstract":"There are many experimental facts that currently cannot be described theoretically. A possible reason is bad mathematical models and algorithms for calculation, despite the many works in this area of research. The aim of this work is to clarificate the mathematical models of describing for rarefied gas and continuous mechanics and to study the errors that arise when we describe a rarefied gas through distribution function. Writing physical values conservation laws via delta functions, the same classical definition of physical values are obtained as in classical mechanics. Usually the derivation of conservation laws is based using the Ostrogradsky-Gauss theorem for a fixed volume without moving. The theorem is a consequence of the application of the integration in parts at the spatial case. In reality, in mechanics and physics gas and liquid move and not only along a forward path, but also rotate. Discarding the out of integral term means ignoring the velocity circulation over the surface of the selected volume. When taking into account the motion of a gas, this term is difficult to introduce into the differential equation. Therefore, to account for all components of the motion, it is proposed to use an integral formulation. Next question is the role of the discreteness of the description of the medium in the kinetic theory and the interaction of the discreteness and \"continuity\" of the media. The question of the relationship between the discreteness of a medium and its description with the help of continuum mechanics arises due to the fact that the distances between molecules in a rarefied gas are finite, the times between collisions are finite, but on definition under calculating derivatives on time and space we deal with infinitely small values. We investigate it","PeriodicalId":39418,"journal":{"name":"WSEAS Transactions on Fluid Mechanics","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46055616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-05-07DOI: 10.37394/232013.2022.17.11
Ivan Kazachkov
The processes of the magnetic tape producing, wire adhering, as well as many other important technological processes, include preparing some special materials’ adhering to a product surface. For a surface withdrawn from the molten metal or the other liquid material there is a problem to determine a profile of a film surface. In this paper, the mathematical model developed for simulation of the adhering process of viscous liquid film to a slowly moving plate, which is vertically withdrawn from the molten metal or the other fluid capacity. The Navier-Stokes equations for a film flow on a surface of the withdrawn plate are considered with the corresponding boundary conditions, and the polynomial approximation is used for the film flow profile. The equations, after integration across the layer of a film flow, result in the system of partial differential equations for the wavy surface ζ(t,x) of a film flow, of flow rate q(t,x) and of flow energy Q(t,x).The derived equations are used for analysis of the nonlinear film flow that determines the quality of a fluid adhering on a surface of the withdrawn plate.
{"title":"Derivation of Nonlinear Equations for Surface of Fluid Adhering to a Moving Plate Withdrawn From Liquid Pool","authors":"Ivan Kazachkov","doi":"10.37394/232013.2022.17.11","DOIUrl":"https://doi.org/10.37394/232013.2022.17.11","url":null,"abstract":"The processes of the magnetic tape producing, wire adhering, as well as many other important technological processes, include preparing some special materials’ adhering to a product surface. For a surface withdrawn from the molten metal or the other liquid material there is a problem to determine a profile of a film surface. In this paper, the mathematical model developed for simulation of the adhering process of viscous liquid film to a slowly moving plate, which is vertically withdrawn from the molten metal or the other fluid capacity. The Navier-Stokes equations for a film flow on a surface of the withdrawn plate are considered with the corresponding boundary conditions, and the polynomial approximation is used for the film flow profile. The equations, after integration across the layer of a film flow, result in the system of partial differential equations for the wavy surface ζ(t,x) of a film flow, of flow rate q(t,x) and of flow energy Q(t,x).The derived equations are used for analysis of the nonlinear film flow that determines the quality of a fluid adhering on a surface of the withdrawn plate.","PeriodicalId":39418,"journal":{"name":"WSEAS Transactions on Fluid Mechanics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43025664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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