scholarly journals Multilayer radiation shield for satellite electronic components protection

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hamideh Daneshvar ◽  
Kavoos Ghordoei Milan ◽  
Ali Sadr ◽  
Seyed Hassan Sedighy ◽  
Shahryar Malekie ◽  
...  
Keyword(s):  
Electronic Device ◽  
Experimental Simulation ◽  
Aluminum Bronze ◽  
Genetic Optimization ◽  
Electronic Components ◽  
Local Protection ◽  
Proton Source ◽  
Space Environments ◽  
Genetic Optimization Algorithm ◽  
Good Agreement

AbstractIn this paper, various multi-layer shields are designed, optimized, and analyzed for electron and proton space environments. The design process is performed for various suitable materials for the local protection of sensitive electronic devices using MCNPX code and the Genetic optimization Algorithm. In the optimizations process, the total ionizing dose is 53.3% and 72% greater than the aluminum shield for proton and electron environments, respectively. Considering the importance of the protons in the LEO orbits, the construction of the shield was based on designing a proton source. A sample shield is built using a combination of Aluminum Bronze and molybdenum layers with a copper carrier to demonstrate the idea. Comparisons of radiation attenuation coefficient results indicate a good agreement between the experimental, simulation, and analytical calculations results. The good specifications of the proposed multi-layer shield prove their capability and ability to use in satellite missions for electronic device protection.

Analytical and Experimental Simulation of Loose Pedestal Dynamic Effects on a Rotating Machine Vibrational Response

1991 ◽  
Author(s):  
Pavel Goldman ◽  
Agnes Muszynska
Keyword(s):  
Excitation Frequency ◽  
Experimental Studies ◽  
Experimental Simulation ◽  
Physical Parameters ◽  
Vibrational Response ◽  
Rotating Machine ◽  
Qualitative Pattern ◽  
The Impact ◽  
Good Agreement ◽  
Periodic Changes

Abstract This report presents experimental, analytical, and numerical results describing vibrational phenomena in a rotating machine with one loose pedestal. The loose-pedestal machine rotor vibrations represent unbalance-related excited vibrations of synchronous and fractional subsynchronous regimes. In this study the loose-pedestal machine is first simulated by a simple vibrating beam excited by a shaker mounted on it. The shaker simulates an unbalanced machine rotor. The beam occasionally enters in contact with the foundation. The excited vibrations are modified by impacting occurrences, and by periodic changes in system stiffness. A new model of the impact has been developed. The results of analytical and experimental studies stand in a good agreement. They illustrate the existence of the synchronous regime and several subsynchronous fractional regimes in various excitation frequency ranges. The analysis adequately predicts the occurrence of these regimes and determines the physical parameters affecting them. The analytical and experimental results are then compared with the responses of experimental rotor rig with one bearing pedestal looseness. They show the same qualitative pattern.

scholarly journals Kinematic Design of a Seven-Bar Linkage with Optimized Centrodes for Pure-Rolling Cutting

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Biao Liu ◽  
Yali Ma ◽  
Delun Wang ◽  
Shaoping Bai ◽  
Yangyang Li ◽  
...  
Keyword(s):  
Optimal Solution ◽  
Genetic Optimization ◽  
Dimensional Synthesis ◽  
Cutting Mechanism ◽  
Pure Rolling ◽  
Moving Points ◽  
Novel Method ◽  
Design Requirements ◽  
Genetic Optimization Algorithm ◽  
Peak Value

A novel method for designing a seven-bar linkage based on the optimization of centrodes is presented in this paper. The proposed method is applied to the design of a pure-rolling cutting mechanism, wherein close interrelation between the contacting lines and centrodes of two pure-rolling bodies is formulated and the genetic optimization algorithm is adopted for the dimensional synthesis of the mechanism. The optimization is conducted to minimize the error between mechanism centrodes and the expected trajectories, subject to the design requirements of the opening distance, the maximum amount of overlap error, and peak value of shearing force. An optimal solution is obtained and the analysis results show that the horizontal slipping and standard deviation of the lowest moving points of the upper shear blade have been reduced by 78.0% and 80.1% and the peak value of shear stress decreases by 29%, which indicate better cutting performance and long service life.

Dynamic Analysis and Parametric Optimization of Telescopic Tubular Mast Applied on Solar Sail

2020 ◽  
Author(s):  
Chen-Yang Ji ◽  
Jin-Guo Liu ◽  
Chen-Chen Wu ◽  
Peng-Yuan Zhao ◽  
Ke-Li Chen
Keyword(s):  
Natural Frequency ◽  
Parametric Design ◽  
Solar Sail ◽  
Work Flow ◽  
Equivalent Model ◽  
Genetic Optimization ◽  
Design And Optimization ◽  
Development Cycle ◽  
Equivalent Load ◽  
Genetic Optimization Algorithm

Abstract The Telescopic Tubular Mast (TTM) has excellent performance and is widely used in aerospace. Reasonable parameter design and optimization can shorten development cycle and improve performance for TTM. This paper designed a TTM driven by the bistable carbon reeled composite boom. The equivalent model of the TTM is established and simulated, which can be used as ex-tending structure for the solar sail. The work flow of the solar sail with the TTM is introduced. The natural frequency of the equivalent model and the segmented model is solved respectively using ABAQUS. The TTM under six different load conditions is analyzed. The influence of different factors on the vibration characteristics of the TTM is analyzed and the sensitivity analysis is carried out. Parameters including stiffness, natural frequency, mass and extension ratio are optimized using the multi-objective genetic optimization algorithm. According to the optimization results, the prototype was processed, and the experiment was completed with the equivalent load of solar sail. It provides a reference for the parametric design of the TTM.

scholarly journals Simulation analysis of heat transfer performance of heat sink with reduced material design

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402092130
Author(s):  
Ya-Chu Chang
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Thermal Resistance ◽  
Heat Sink ◽  
Heat Transfer Performance ◽  
Electronic Device ◽  
Local Heating ◽  
Transfer Performance ◽  
Electronic Components ◽  
Thermal Reliability

The field of electronic device applications is becoming more and more extensive. With the development of science and technology and the improvement of the integration of electronic components, local heating is becoming more and more serious. If heat cannot be discharged immediately, it will cause heat to accumulate, causing the temperature of each component to exceed the limit. The reliability of electronic equipment is greatly reduced. Especially in important fields such as military and aerospace, the thermal reliability of electronic components is higher. The research results show that increasing the Reynolds number is helpful to reduce the overall temperature and thermal resistance of the heat sink, but the increase of the Reynolds number and the decrease of the thermal resistance value are gradually flat. The design concept of material reduction has a significant impact on processing and cost. The results of this article show that selecting the appropriate heat sink fins and matching the specific Reynolds number can effectively improve the heat transfer performance of the heat sink.

Thermal analysis of HVAC and solar panels using genetic optimization algorithm

2016 ◽  
Vol 30 (3) ◽  
pp. 1405-1412 ◽  
Author(s):  
Ardeshir Moftakhari ◽  
Cyrus Aghanajafi ◽  
Ardalan Moftakhari Chaei Ghazvin
Keyword(s):  
Thermal Analysis ◽  
Optimization Algorithm ◽  
Genetic Optimization ◽  
Solar Panels ◽  
Genetic Optimization Algorithm
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