Aerospace Science and Technology
alireza moradi; fathollah ommi; Zoheir Saboohi
Abstract
In the course of all-round advancement of engineering science, space research can be considered as the drivers of this forward movement. In the field of space propulsion, this trend can be seen as a backward trend, not in the sense of regression, but in the sense of optimizing the original designs used ...
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In the course of all-round advancement of engineering science, space research can be considered as the drivers of this forward movement. In the field of space propulsion, this trend can be seen as a backward trend, not in the sense of regression, but in the sense of optimizing the original designs used for space systems, which not only lead to the re-invention of these systems based on the acquisition of specific modern manufacturing technologies, but also strengthened the link between sciences such as Materials science and Mechanics science. In this research, according to the space propulsion system roadmap and also the review of old and reference designs, an attempt has been made to study some of the optimizations made in recent years and to express the weaknesses and challenges ahead. One of the ideas that optimizes, minimizes and increases the reliability of the space propulsion system is the injection of fuel through the porous media. The study of a type of showerhead injector expresses the formation path of the idea of using porous materials in the injection system and then the efficiency of these two types of injections is compared in a design that connects the porous material with the coaxial injector design.
Fathollah Ommi; Hamidreza Khodayari; Zoheir Saboohi
Abstract
Butterfly valves as control valves are used when a small pressure drop is required in the valve. The results of numerical studies of solving the incompressible flow equations around the butterfly valve in three dimensions are presented in this paper. ANSYS CFX commercial software is used to solve the ...
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Butterfly valves as control valves are used when a small pressure drop is required in the valve. The results of numerical studies of solving the incompressible flow equations around the butterfly valve in three dimensions are presented in this paper. ANSYS CFX commercial software is used to solve the flow equations. The ε-k turbulence model is used to simulate flow disturbances. Velocity, pressure distribution, kinetic energy, and turbulence intensity profiles are the factors that provide flow characteristics. The position of the disk at the opening angles of 0˚, 15˚, 30˚, 45˚, 60˚, and 75˚ as well as the inlet velocities of 1, 2, and 3 m/s have been investigated. Torque and valve performance factors such as flow coefficient and Hydrodynamics torque coefficient have been calculated for these different opening angles. The results of this simulation have been compared with the available experimental results for validation. The results show that the pressure drop across the valve, the flow coefficient, and the hydrodynamic torque coefficient depend on the opening angle. As the opening angle increases, the flow coefficient and the hydrodynamic torque coefficient decrease, and the torque and pressure drop increase across the valve. Flow separation has also been investigated at the mentioned opening angles.
