The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
M E Matbouly - One of the best experts on this subject based on the ideXlab platform.
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Reduction of Radial Thrust by using triple-volute casing
Ain Shams Engineering Journal, 2019Co-Authors: Ehab M. Mina, R N Abdelmessih, M E MatboulyAbstract:Abstract A complete centrifugal pump is designed and manufactured. The volute is designed such that partition vanes could be added to change the number of volutes. Experiments were performed on single-, double-, triple-volute centrifugal pump at 500, 800, and 900 rpm for each case. The results reveal that the non-dimensional performance curves for the three pumps are identical. The efficiency is increased due to the presence of the partition vane. The use of multiple-volute reduces the Radial Thrust. This reduction is more significant as the operation departs the BEP. At shut off, where the problem is most critical, the use of two- and three-volute reduces the Radial Thrust by 54% and 72%, respectively, below the Thrust of a single volute pump.
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Reduction of Radial Thrust by Using Triple-Volute Casing Centrifugal Pump
International Conference on Aerospace Sciences and Aviation Technology, 2018Co-Authors: Ehab M. Mina, R N Abdelmessih, M E MatboulyAbstract:Radial Thrust in a single volute centrifugal pump, which is a result of pressure variation in the volute casing, is investigated in order to avoid failures caused by this Thrust force. Two ideas are introduced to avoid or to minimize this Thrust force, the first is a double volute, and the second is a triple volute. A complete centrifugal pump design was manufactured. The volute was designed such that partition vanes could be added to change the number of volutes. Experiments were performed on single, double, triple volutes centrifugal pump at 500, 800, and 900 rpm for each case. The performances of the three pumps as seen on a non-dimensional plot, are nearly the same in the three casing types (Single, double and triple volutes). However, the values of the efficiency reveal an improvement associated with the presence of the volute(s)On the other hand, the use of multiple volutes reduced the Radial Thrust force. These reductions were pronounced as the departure from the BEP was increased. At shut off for instance, the Radial Thrusts for the double volutes and triple volutes were reduced by 55% and 70%, respectively, below the Thrust of a single volute pump.
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REDUCTION OF Radial Thrust BY USING TRIPLE-VOLUTE CASING
Journal of Al-Azhar University Engineering Sector, 2016Co-Authors: A M Mina, R N Abdelmessih, M E MatboulyAbstract:Radial Thrust in a single volute centrifugal pump, which is a result of pressure variation in the volute casing, is investigated in order to avoid failures caused by this Thrust force. Two ideas are introduced to avoid or to minimize this Thrust force, the first is a double volute, and the second is a triple volute. A complete centrifugal pump design was manufactured. The volute was designed such that partition vanes could be added to change the number of volutes. Experiments were performed on single volute centrifugal pump, double volute centrifugal pump and triple volute centrifugal pump at 500, 800, and 900 rpm for each case. The Thrust values of the double volute pump are always lower than that of the single volute pump specially when operating far from the best efficiency point where, the Radial Thrust is reduced by more than 55% at shut off and more than 40% at high discharges, while the Thrust values of the triple volute are always lower than that of the single volute and double volute pumps specially when operating far from the best efficiency point where, the Radial Thrust is reduced by more than 70% at shut off and more than 50% at high discharges comparing to single volute and the Radial Thrust is reduced by more than 40% at shut off and more than 20% at high discharges comparing to double volute . However, it is to be mentioned that the best pump efficiency is always obtained for the single volute pump, compared with the other alternatives.
Ehab M. Mina - One of the best experts on this subject based on the ideXlab platform.
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Reduction of Radial Thrust by using triple-volute casing
Ain Shams Engineering Journal, 2019Co-Authors: Ehab M. Mina, R N Abdelmessih, M E MatboulyAbstract:Abstract A complete centrifugal pump is designed and manufactured. The volute is designed such that partition vanes could be added to change the number of volutes. Experiments were performed on single-, double-, triple-volute centrifugal pump at 500, 800, and 900 rpm for each case. The results reveal that the non-dimensional performance curves for the three pumps are identical. The efficiency is increased due to the presence of the partition vane. The use of multiple-volute reduces the Radial Thrust. This reduction is more significant as the operation departs the BEP. At shut off, where the problem is most critical, the use of two- and three-volute reduces the Radial Thrust by 54% and 72%, respectively, below the Thrust of a single volute pump.
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Reduction of Radial Thrust by Using Triple-Volute Casing Centrifugal Pump
International Conference on Aerospace Sciences and Aviation Technology, 2018Co-Authors: Ehab M. Mina, R N Abdelmessih, M E MatboulyAbstract:Radial Thrust in a single volute centrifugal pump, which is a result of pressure variation in the volute casing, is investigated in order to avoid failures caused by this Thrust force. Two ideas are introduced to avoid or to minimize this Thrust force, the first is a double volute, and the second is a triple volute. A complete centrifugal pump design was manufactured. The volute was designed such that partition vanes could be added to change the number of volutes. Experiments were performed on single, double, triple volutes centrifugal pump at 500, 800, and 900 rpm for each case. The performances of the three pumps as seen on a non-dimensional plot, are nearly the same in the three casing types (Single, double and triple volutes). However, the values of the efficiency reveal an improvement associated with the presence of the volute(s)On the other hand, the use of multiple volutes reduced the Radial Thrust force. These reductions were pronounced as the departure from the BEP was increased. At shut off for instance, the Radial Thrusts for the double volutes and triple volutes were reduced by 55% and 70%, respectively, below the Thrust of a single volute pump.
Mário César Ricci - One of the best experts on this subject based on the ideXlab platform.
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Ball's motion, sliding friction, and internal load distribution in a high-speed ball bearing subjected to a combined Radial, Thrust, and moment load, applied to the inner ring's center of mass: Numerical procedure
Journal of Physics: Conference Series, 2015Co-Authors: Mário César RicciAbstract:A set of non-linear algebraic equations, which must to be solved using a numerical procedure, for ball's motion, sliding friction and internal loading distribution computation in a high-speed, single-row, angular-contact ball bearing, subjected to a known combined Radial, Thrust and moment load, which must be applied to the inner ring's centre of mass, is introduced. For each step of the procedure it is required the iterative solution of 9Z + 3 simultaneous non-linear equations—where Z is the number of the balls—to yield exact solution for contact angles, ball attitude angles, rolling radii, normal contact deformations and axial, Radial, and angular deflections of the inner ring with respect the outer ring. While the focus of this work is obtaining the steady state forces and moments equilibrium conditions on the balls, under the selected loading, the numerical aspects of the procedure are treated in a companion paper. The numerical results derived from the described procedure shall be published later.
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Invited: Ball’s motion, sliding friction and internal load distribution in a high-speed ball bearing subjected to a combined Radial, Thrust, and moment load
2015Co-Authors: Mário César RicciAbstract:A set of non-linear algebraic equations, which must to be solved using a numerical procedure, for ball’s motion, sliding friction and internal loading distribution computation in a high-speed, single-row, angular-contact ball bearing, subjected to a known combined Radial, Thrust and moment load, which must be applied to the inner ring’s centre of mass, is introduced. For each step of the procedure it is required the iterative solution of 9 Z + 3 simultaneous non-linear equations – where Z is the number of the balls – to yield exact solution for contact angles, ball attitude angles, rolling radii, normal contact deformations and axial, Radial, and angular deflections of the inner ring with respect the outer ring. The focus of this work is obtaining the steady state forces and moments equilibrium conditions on the balls, under the selected external loading, and to describe the numerical aspects of the procedure. The numerical results derived from the described procedure shall be published later.
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internal loading distribution in statically loaded ball bearings subjected to a combined Radial and Thrust load including the effects of temperature and fit
World Academy of Science Engineering and Technology International Journal of Mechanical Aerospace Industrial Mechatronic and Manufacturing Engineering, 2009Co-Authors: Mário César RicciAbstract:A new, rapidly convergent, numerical procedure for internal loading distribution computation in statically loaded, single-row, angular-contact ball bearings, subjected to a known combined Radial, Thrust, and moment load, is used to find the load distribution differences between a loaded unfitted bearing at room temperature, and the same loaded bearing with interference fits which might experience Radial temperature gradients between inner and outer rings. For each step of the procedure it is required the iterative solution of Z + 3 simultaneous nonlinear equations – where Z is the number of the balls – to yield exact solution for axial, Radial, and angular deflections, and contact angles. Numerical results are shown for a 218 angular-contact ball bearing.
R N Abdelmessih - One of the best experts on this subject based on the ideXlab platform.
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Reduction of Radial Thrust by using triple-volute casing
Ain Shams Engineering Journal, 2019Co-Authors: Ehab M. Mina, R N Abdelmessih, M E MatboulyAbstract:Abstract A complete centrifugal pump is designed and manufactured. The volute is designed such that partition vanes could be added to change the number of volutes. Experiments were performed on single-, double-, triple-volute centrifugal pump at 500, 800, and 900 rpm for each case. The results reveal that the non-dimensional performance curves for the three pumps are identical. The efficiency is increased due to the presence of the partition vane. The use of multiple-volute reduces the Radial Thrust. This reduction is more significant as the operation departs the BEP. At shut off, where the problem is most critical, the use of two- and three-volute reduces the Radial Thrust by 54% and 72%, respectively, below the Thrust of a single volute pump.
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Reduction of Radial Thrust by Using Triple-Volute Casing Centrifugal Pump
International Conference on Aerospace Sciences and Aviation Technology, 2018Co-Authors: Ehab M. Mina, R N Abdelmessih, M E MatboulyAbstract:Radial Thrust in a single volute centrifugal pump, which is a result of pressure variation in the volute casing, is investigated in order to avoid failures caused by this Thrust force. Two ideas are introduced to avoid or to minimize this Thrust force, the first is a double volute, and the second is a triple volute. A complete centrifugal pump design was manufactured. The volute was designed such that partition vanes could be added to change the number of volutes. Experiments were performed on single, double, triple volutes centrifugal pump at 500, 800, and 900 rpm for each case. The performances of the three pumps as seen on a non-dimensional plot, are nearly the same in the three casing types (Single, double and triple volutes). However, the values of the efficiency reveal an improvement associated with the presence of the volute(s)On the other hand, the use of multiple volutes reduced the Radial Thrust force. These reductions were pronounced as the departure from the BEP was increased. At shut off for instance, the Radial Thrusts for the double volutes and triple volutes were reduced by 55% and 70%, respectively, below the Thrust of a single volute pump.
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REDUCTION OF Radial Thrust BY USING TRIPLE-VOLUTE CASING
Journal of Al-Azhar University Engineering Sector, 2016Co-Authors: A M Mina, R N Abdelmessih, M E MatboulyAbstract:Radial Thrust in a single volute centrifugal pump, which is a result of pressure variation in the volute casing, is investigated in order to avoid failures caused by this Thrust force. Two ideas are introduced to avoid or to minimize this Thrust force, the first is a double volute, and the second is a triple volute. A complete centrifugal pump design was manufactured. The volute was designed such that partition vanes could be added to change the number of volutes. Experiments were performed on single volute centrifugal pump, double volute centrifugal pump and triple volute centrifugal pump at 500, 800, and 900 rpm for each case. The Thrust values of the double volute pump are always lower than that of the single volute pump specially when operating far from the best efficiency point where, the Radial Thrust is reduced by more than 55% at shut off and more than 40% at high discharges, while the Thrust values of the triple volute are always lower than that of the single volute and double volute pumps specially when operating far from the best efficiency point where, the Radial Thrust is reduced by more than 70% at shut off and more than 50% at high discharges comparing to single volute and the Radial Thrust is reduced by more than 40% at shut off and more than 20% at high discharges comparing to double volute . However, it is to be mentioned that the best pump efficiency is always obtained for the single volute pump, compared with the other alternatives.
Giovanni Mengali - One of the best experts on this subject based on the ideXlab platform.
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Electric sail phasing maneuvers with Radial Thrust
Acta Astronautica, 2021Co-Authors: Marco Bassetto, Giovanni Mengali, Luisa Boni, Alessandro Antonio QuartaAbstract:Abstract We address the heliocentric in-orbit repositioning problem of an E-sail-based spacecraft that covers a circular parking orbit of given radius, with the assumption that the propulsive acceleration is directed along the Sun-spacecraft line. According to the recent literature, the analysis exploits the possibility of reducing the mathematical problem to the dynamics of an equivalent nonlinear oscillator with a single degree of freedom. The analytical expression of the spacecraft heliocentric trajectory, which is available in polar form when its motion is periodic, is used to obtain approximate relationships among the E-sail performance, the flight time, and the desired phasing angle. The approximate analytical model is validated through numerical simulations, whereas the last part of the paper discusses a comparison with the optimal in-orbit repositioning transfers available in the literature.
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Spiral trajectories induced by Radial Thrust with applications to generalized sails
Astrodynamics, 2020Co-Authors: Marco Bassetto, Alessandro A. Quarta, Giovanni Mengali, Vittorio CipollaAbstract:In this study, new analytical solutions to the equations of motion of a propelled spacecraft are investigated using a shape-based approach. There is an assumption that the spacecraft travels a two-dimensional spiral trajectory in which the orbital radius is proportional to an assigned power of the spacecraft angular coordinate. The exact solution to the equations of motion is obtained as a function of time in the case of a purely Radial Thrust, and the propulsive acceleration magnitude necessary for the spacecraft to track the prescribed spiral trajectory is found in a closed form. The analytical results are then specialized to the case of a generalized sail, that is, a propulsion system capable of providing an outward Radial propulsive acceleration, the magnitude of which depends on a given power of the Sun-spacecraft distance. In particular, the conditions for an outward Radial Thrust and the required sail performance are quantified and thoroughly discussed. It is worth noting that these propulsion systems provide a purely Radial Thrust when their orientation is Sun-facing. This is an important advantage from an engineering point of view because, depending on the particular propulsion system, a Sun-facing attitude can be stable or obtainable in a passive way. A case study is finally presented, where the generalized sail is assumed to start the spiral trajectory from the Earth’s heliocentric orbit. The main outcome is that the required sail performance is in principle achievable on the basis of many results available in the literature.
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Analysis of Electric Sail Heliocentric Motion Under Radial Thrust
Journal of Guidance Control and Dynamics, 2016Co-Authors: Alessandro Antonio Quarta, Giovanni MengaliAbstract:The contribution of this Note is to analyze the heliocentric trajectory of an E-sail with an outward Radial Thrust by reducing the problem, by means of a suitable change of variables, to the dynamics of a known equivalent nonlinear oscillator with a single degree of freedom. An analytical, albeit approximate, expression of the spacecraft heliocentric trajectory is also given in polar form when the motion is periodic. This result is shown to be sufficiently accurate for a preliminary mission analysis and is obtained with a reduced computational time, considerably smaller than what is necessary for a numerical integration of the spacecraft equations of motion
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Artificial equilibrium points for a generalized sail in the circular restricted three-body problem
Celestial Mechanics and Dynamical Astronomy, 2011Co-Authors: Generoso Aliasi, Giovanni Mengali, Alessandro A. QuartaAbstract:This paper introduces a new approach to the study of artificial equilibrium points in the circular restricted three-body problem for propulsion systems with continuous and purely Radial Thrust. The propulsion system is described by means of a general mathematical model that encompasses the behavior of different systems like a solar sail, a magnetic sail and an electric sail. The proposed model is based on the choice of a coefficient related to the propulsion type and a performance parameter that quantifies the system technological complexity. The propulsion system is therefore referred to as generalized sail. The existence of artificial equilibrium points for a generalized sail is investigated. It is shown that three different families of equilibrium points exist, and their characteristic locus is described geometrically by varying the value of the performance parameter. The linear stability of the artificial points is also discussed.
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Analytical results for solar sail optimal missions with modulated Radial Thrust
Celestial Mechanics and Dynamical Astronomy, 2010Co-Authors: Alessandro A. Quarta, Giovanni MengaliAbstract:The aim of this paper is to analyze the optimal trajectories of a spacecraft subjected to a modulated Radial Thrust, whose magnitude is inversely proportional to the square of the distance from the primary body. This case is representative of a Sun-facing solar sail with a passive attitude control system. In this study the sailcraft is assumed to perform a finite number of reorientation maneuvers to set the propelling acceleration to zero and generate suitable coasting arcs along the trajectory. Accordingly, the resulting generalized orbit is a sequence of either propelled or ballistic conic arcs, whose main characteristics (in terms of semimajor axis, eccentricity, and perihelion radius) can be calculated in closed form. As a result, the sailcraft optimal performance can be studied using an analytical approach. In particular, some compact relationships are drawn and discussed that allow one to find the optimal sailcraft characteristics required to reach a prescribed final orbit.
