Space systems design (spacecraft, satellites, space stations and their equipment)
Armin Azodi; Meysam Mohammadi Amin; Saeed Mahmoudkhani
Volume 15, Issue 3 , September 2022, , Pages 49-66
Abstract
In the present work, the frequency-domain aeroelastic stability analysis of space launch vehicle body in the flight condition of initial launch phase is presented for a range of geometric parameters, structural characteristics, and other parameters such as thrust force. The aeroelastic model is derived ...
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In the present work, the frequency-domain aeroelastic stability analysis of space launch vehicle body in the flight condition of initial launch phase is presented for a range of geometric parameters, structural characteristics, and other parameters such as thrust force. The aeroelastic model is derived using structural assumed modes and quasi-steady aerodynamics. The pressure distribution of subsonic flow on the 3D configuration is determined by boundary element method. Non-uniform Euler-Bernoulli beam including torsion spring junctions along the body with free-free ends is used to model the structure, and its modal analysis is performed by finite difference method. Concluded results illustrate variation in parameters not only could vary the aeroelastic instability boundary, but also might cause the instability type changed (from divergence to flutter), which its main reason is replacement the second instability of the aeroelastic system with the first one. Furthermore, it is demonstrated that the follower thrust force restricts the aeroelastic stability but maintains the instability type.
Seyed Moein Mahmoodzadeh Entezari; Alireza Alikhani; Meysam Mohammadi Amin
Volume 13, Issue 2 , June 2020, , Pages 51-61
Abstract
In this study, a method for designing a thermal optimum reentry path based on aerodynamic database management has been developed using the Kriging and Co-Kriging methods. For the design of the reentry path in the conceptual design phase, the more precise the dynamical model of the reentry vehicle, the ...
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In this study, a method for designing a thermal optimum reentry path based on aerodynamic database management has been developed using the Kriging and Co-Kriging methods. For the design of the reentry path in the conceptual design phase, the more precise the dynamical model of the reentry vehicle, the closer the path is to reality. One of the issues affecting the accuracy of the dynamic model of return vehicle is the aerodynamic coefficients in its flight envelope. For this purpose, in the present study using the new method, accurate aerodynamic data has been developed by combining the data from different solvers in the device flight envelope at the appropriate time. In the following, using the dynamic model and the developed reentry path design algorithm, the thermal optimal return path of the Orion device with constant coefficients and the exact aerodynamic database are compared, and the important parameters of reentry path, such as thermal flux and final velocity, are evaluated.
Nima Karimi; محمد علی فارسی
Volume 13, Issue 1 , March 2020, , Pages 13-23
Abstract
In the present paper, the process of designing launch abort system is presented for manned spacecraft in sub-orbital mission. For this purpose, by studying the other manned spacecraft launch abort system, a number of dimensionless parameters have been generated for the launch abort system and spacecraft. ...
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In the present paper, the process of designing launch abort system is presented for manned spacecraft in sub-orbital mission. For this purpose, by studying the other manned spacecraft launch abort system, a number of dimensionless parameters have been generated for the launch abort system and spacecraft. using these parameters, the mass, geometric-dimensional characteristics, the launch escape motor thrust and acceleration of the LAS have been estimated. Also The numerical aerodynamic analysis has been used to form the external configuration, and the results of the analysis, along with other effective parameters, have created a design framework. AHP analysis has been used to select the optimal configuration and in order to validation, an analytical model based on the momentum equation used to design the launch escape motor. Comparison of the results of this model and the statistical design has shown that the data produced is correct.
Ghasem Kahe; Maysam Mohammadi-Amin; Arash Sefidan Benisi
Volume 10, Issue 1 , June 2017, , Pages 1-13
Abstract
Various strategies have been developed to increase the safety of spacecraft crews, among which the Launch Abort System has been widely considered by the space centers across the world. The launch abort system should be able to carry the crew module away from the failed launcher or rocket in a short time ...
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Various strategies have been developed to increase the safety of spacecraft crews, among which the Launch Abort System has been widely considered by the space centers across the world. The launch abort system should be able to carry the crew module away from the failed launcher or rocket in a short time in accordance with the predetermined profile and recover the crew module on the ground. While the main part of the vehicle flight consists of the tracking, reorientation, and settling phase; attitude control in the flight path is done via the roll and pitch channel. Non-linear dynamic inversion flight control is considered for the attitude control of the LAS. Tracking the predetermined profile for the angle of attack as well as the sideslip angle and maintaining the stability of the vehicle in the flight path are considered as the control objectives based on the requirements. Simulations and analytical evaluations indicate the outperformance of the proposed controller for the attitude control of LAS in line with the predetermined profile.
