In this study we examine the situation at which a valve is closed against fluid flow in a long p... more In this study we examine the situation at which a valve is closed against fluid flow in a long pipeline. The solution here obtained shows that the closure of the valve divided the flow region in the pipeline into several zones. Each zone is separated from the other one by two moving boundaries. One boundary is the upstream moving boundary and the other one is the downstream moving boundary. The dependence between the closing rate of the valves and the number of flow zones, that are created in the pipeline, was also presented, In addition to this, a calibration method that use the above mentioned dependency, was presented.
In this study we examine the situation at which a valve is closed against fluid flow in a long p... more In this study we examine the situation at which a valve is closed against fluid flow in a long pipeline. The solution here obtained shows that the closure of the valve divided the flow region in the pipeline into several zones. Each zone is separated from the other one by two moving boundaries. One boundary is the upstream moving boundary and the other one is the downstream moving boundary. The dependence between the closing rate of the valves and the number of flow zones, that are created in the pipeline, was also presented, In addition to this, a calibration method that use the above mentioned dependency, was presented.
A plane axisymmetric (radially converging) flow occurs in case of water extraction from an aquife... more A plane axisymmetric (radially converging) flow occurs in case of water extraction from an aquifer through a well. A new physico-mathematical approach is developed for modeling oil pollutant migration near an extraction well in the aquifer. This is done by considering the various dimensionless parameters governing the transport processes and by applying a self-similar scheme. The time-dependent saturation profiles, calculated from several exact analytical solutions, exhibit the effects of various dimensionless parameters related to oil migration, directed to a water extraction well. By using hypothetical saturation data, the model was calibrated and a predication of the temporal oil saturation distribution around the well was calculated.
In this study we refer to a non-steady state, one-dimensional (on the x-axis), unconfined and sat... more In this study we refer to a non-steady state, one-dimensional (on the x-axis), unconfined and satu-rated flow in an aquifer, described by the Boussinesq equation, combined with accretion. In ac-cordance with the above, the moving boundary of the saturated area (toward x → +∞) serves as a horizontal water flux source to the unsaturated area. As time advances, the horizontally saturated zone, lying on the x-axis, becomes wider. A self-similar solution is derived that, after some ma-thematical manipulation, it is described in terms of Hypergeometric functions. The long-time be-haviors of the solution describe the situation at which the water flux, that penetrates horizontally to the non-saturated zone, is equal to the water flux entering into the saturated zone.
The present study uses the self-similar approach, developed by Pistiner (2020), for solving the w... more The present study uses the self-similar approach, developed by Pistiner (2020), for solving the water hammer equation during the process of valve closure in infinite long pipeline. The obtained solution shows that the transient flow in the pipeline is characterized by three zones: the “near zone” located near the closing valve and is characterized by a positive flow; the “far zone” in the pipeline lying at an infinite distance from the valve where the flow is also positive and the “intermediate backflow zone”, which is lying among the above-mentioned zones and is characterized by reverse flow. The results obtained in this study may be useful to give some insights into the understanding of transient flow process in pipes as well as provide approximate estimation for transient waves in pipes and finally, the applicability of the model to predict head distribution in the pipeline has been shown.
In this study we examine the situation at which a valve is closed against fluid flow in a long p... more In this study we examine the situation at which a valve is closed against fluid flow in a long pipeline. The solution here obtained shows that the closure of the valve divided the flow region in the pipeline into several zones. Each zone is separated from the other one by two moving boundaries. One boundary is the upstream moving boundary and the other one is the downstream moving boundary. The dependence between the closing rate of the valves and the number of flow zones, that are created in the pipeline, was also presented, In addition to this, a calibration method that use the above mentioned dependency, was presented.
In this study we examine the situation at which a valve is closed against fluid flow in a long p... more In this study we examine the situation at which a valve is closed against fluid flow in a long pipeline. The solution here obtained shows that the closure of the valve divided the flow region in the pipeline into several zones. Each zone is separated from the other one by two moving boundaries. One boundary is the upstream moving boundary and the other one is the downstream moving boundary. The dependence between the closing rate of the valves and the number of flow zones, that are created in the pipeline, was also presented, In addition to this, a calibration method that use the above mentioned dependency, was presented.
A plane axisymmetric (radially converging) flow occurs in case of water extraction from an aquife... more A plane axisymmetric (radially converging) flow occurs in case of water extraction from an aquifer through a well. A new physico-mathematical approach is developed for modeling oil pollutant migration near an extraction well in the aquifer. This is done by considering the various dimensionless parameters governing the transport processes and by applying a self-similar scheme. The time-dependent saturation profiles, calculated from several exact analytical solutions, exhibit the effects of various dimensionless parameters related to oil migration, directed to a water extraction well. By using hypothetical saturation data, the model was calibrated and a predication of the temporal oil saturation distribution around the well was calculated.
In this study we refer to a non-steady state, one-dimensional (on the x-axis), unconfined and sat... more In this study we refer to a non-steady state, one-dimensional (on the x-axis), unconfined and satu-rated flow in an aquifer, described by the Boussinesq equation, combined with accretion. In ac-cordance with the above, the moving boundary of the saturated area (toward x → +∞) serves as a horizontal water flux source to the unsaturated area. As time advances, the horizontally saturated zone, lying on the x-axis, becomes wider. A self-similar solution is derived that, after some ma-thematical manipulation, it is described in terms of Hypergeometric functions. The long-time be-haviors of the solution describe the situation at which the water flux, that penetrates horizontally to the non-saturated zone, is equal to the water flux entering into the saturated zone.
The present study uses the self-similar approach, developed by Pistiner (2020), for solving the w... more The present study uses the self-similar approach, developed by Pistiner (2020), for solving the water hammer equation during the process of valve closure in infinite long pipeline. The obtained solution shows that the transient flow in the pipeline is characterized by three zones: the “near zone” located near the closing valve and is characterized by a positive flow; the “far zone” in the pipeline lying at an infinite distance from the valve where the flow is also positive and the “intermediate backflow zone”, which is lying among the above-mentioned zones and is characterized by reverse flow. The results obtained in this study may be useful to give some insights into the understanding of transient flow process in pipes as well as provide approximate estimation for transient waves in pipes and finally, the applicability of the model to predict head distribution in the pipeline has been shown.
Uploads
Papers by arieh pistiner