Space New Technologies
Pedram Hajipour; Roghieh Karimzadeh Baee; Houman Zarrabi; Roghayeh Doost; Leila Mohammadi
Articles in Press, Accepted Manuscript, Available Online from 05 February 2023
Abstract
According to the technical specifications of the future generations of telecommunication (the fifth generation and later), which should provide new services with very high data rates in the minimum time and a wide coverage, as well as the exponential increase in traffic, the use of combined space-air ...
Read More
According to the technical specifications of the future generations of telecommunication (the fifth generation and later), which should provide new services with very high data rates in the minimum time and a wide coverage, as well as the exponential increase in traffic, the use of combined space-air networks Land is essential. It should be noted that the management of this type of combined networks has major challenges in providing such services. Meanwhile, the intelligent management of resources in satellite-based hybrid networks will lead to increased capacity and improved service quality. For this purpose, in this article, a comprehensive review of the use of artificial intelligence in the field of satellite communications will be discussed. In the field of intelligent increase of capacity, various factors such as how to configure the network, how to allocate resources such as spectrum, energy and power will be investigated with consideration of intelligent interference management. Finally, in the field of service quality improvement, factors such as how to model and intelligently predict traffic, as well as how to deal with harmful environmental conditions, will be presented.
Space New Technologies
Hassan Naseh; Ali Alipoor
Volume 16, Issue 1 , April 2023, , Pages 23-34
Abstract
The main purpose is to introduce the performance system design and optimization method of aerospike nozzle for different aero-space conditions. For this purpose, some of the important parameters of the aerospike nozzle structure and cold flow condition tests in the nozzle optimization are studied. The ...
Read More
The main purpose is to introduce the performance system design and optimization method of aerospike nozzle for different aero-space conditions. For this purpose, some of the important parameters of the aerospike nozzle structure and cold flow condition tests in the nozzle optimization are studied. The methods of designing the Aerospike nozzle and its governing equations are described and the proposed design model is described and important factors are expressed in this type of nozzle. therefore, the design of a complete nozzle is made by aerospike and is supported by an existing design sample. Then, in order to optimize the nozzle, three cuts of 20%, 40% and 60% of the nozzle end are analyzed. The standard for comparison and optimization in these three slices is the Mach number of the output current. The results of this comparison show that the most efficient aerospike nozzle is a 40% cut nozzle based on the flow charts and contours of this aerospace nozzle.
Space New Technologies
Sadjad Samipour; Alireza Toloui; Vladimir Batrakoff
Volume 15, Issue 4 , January 2023, , Pages 33-45
Abstract
Development in the aerospace industry is linked to the continuous pursuit of lightweight designs. Open-architecture composite structures are a new and novel use of composites for minimal-weight component design. It is reasonable to use efficient and advanced techniques such as radial braiding in the ...
Read More
Development in the aerospace industry is linked to the continuous pursuit of lightweight designs. Open-architecture composite structures are a new and novel use of composites for minimal-weight component design. It is reasonable to use efficient and advanced techniques such as radial braiding in the manufacturing of composite lattice tubular structures. In this article, an aerospace composite lattice tubular structure with a braided reinforcement system is studied. A method is developed to determine the parameters of the preform reinforcement. A new process has been created for the manufacture of lattice structures with a braided reinforcement system. A methodology has been developed for determining the technological parameters of radial braiding. A sample structure is manufactured and tested. Experimental studies of lattice structure samples were carried out in order to verify the methods for determining mechanical, structural, and technological parameters.
Space New Technologies
Hassan Naseh; Mostafa Jafarpanah
Volume 15, Issue 3 , September 2022, , Pages 83-96
Abstract
The purpose of this paper is to present the cost estimation and optimization of space propulsion systems. Thus, choosing optimal propulsion system (from fuel and oxidizer aspect) is done in order to increase the efficiency and decrease the cost. Also, human resource cost and technology development time ...
Read More
The purpose of this paper is to present the cost estimation and optimization of space propulsion systems. Thus, choosing optimal propulsion system (from fuel and oxidizer aspect) is done in order to increase the efficiency and decrease the cost. Also, human resource cost and technology development time based on the consideration of labor cost effect on the personals motivation have been optimized. To this end, cost estimation and optimization algorithm has been drawn and suggested. The suggested algorithm has two steps. The first step in the algorithm is concern to cost estimation for seven fuel and oxidizer components. In the second step, labor cost and project implementation time is estimated and optimized based on the optimal space propulsion system derived from the previous step. Here, the objective functions are propulsion system technology development cost and time. On the other hand, the purpose is to consider the salary enhancement and consequently efficiency enhancement, time decrease and cost decrease.
Space New Technologies
Reza Kohandani; Ali Davar; Mohsen Heydari Beni; Jafar Eskandari Jam; Majid Eskandari Shahraki
Volume 15, Issue 1 , March 2022, , Pages 1-21
Abstract
In this research the free vibration analysis of simply supported grid stiffened doubly curved shells by using a refined higher order theory is presented. The advantage of the present theory in comparison with other higher order theories is investigation of the effects of trapezoidal shape factor in the ...
Read More
In this research the free vibration analysis of simply supported grid stiffened doubly curved shells by using a refined higher order theory is presented. The advantage of the present theory in comparison with other higher order theories is investigation of the effects of trapezoidal shape factor in the stress resultants in order to obtain more accurate frequency results. The governing equations of motion and boundary conditions are obtained using Hamilton’s principle and solved by using the Galerkin method. In the case of grid stiffened shells, a distribution function is introduced for describing the physical discontinuity between the ribs and the bays. The results are validated by making comparison to those existed in the literature or those obtained using the present numerical simulation in ABAQUS/Standard solver. In most cases, validations illustrated excellent agreement between the results . Finally, the effects of geometrical properties, material property and layup on the frequency responses of the shell are discussed.
