Iranian Space Agency ISA

Tehrān, Iran

Iranian Space Agency ISA

Tehrān, Iran
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Shayan M.,Research Institute for Astronomy and Astrophysics of Maragha RIAAM | Davoudifar P.,Research Institute for Astronomy and Astrophysics of Maragha RIAAM | Bagheri Z.,Iranian Space Agency ISA
Advances in Space Research | Year: 2017

In General, the flux of low energy cosmic rays varies with time due to solar activities. The cosmic particle fluxes were studied using data of satellites near the Earth. In this work, first we studied the variations of particle fluxes from 1 Jan to 31 Dec 2000 and 35 events were selected. Then we proposed a relation for cosmic particle flux as a function of time and rigidity in the time of approaching ejecta to the Earth. The coefficients of the relation were calculated using experimental data of particle fluxes from ACE satellite. Finally, we compare time variations of these coefficients for different events. © 2017 COSPAR.


Jazebizadeh H.,Shahid Beheshti University | Tabeshian M.,Iranian Space Agency ISA | Taheran Vernoosfaderani M.,GMV Aerospace and Defense S.A.
Acta Astronautica | Year: 2010

Although more than half a century is passed since space technology was first developed, developing countries are just beginning to enter the arena, focusing mainly on educating professionals. Space technology by itself is an interdisciplinary science, is costly, and developing at a fast pace. Moreover, a fruitful education system needs to remain dynamic if the quality of education is the main concern, making it a complicated system. This paper makes use of the System Engineering Approach and the experiences of developed countries in this area while incorporating the needs of the developing countries to devise a comprehensive program in space engineering at the Master's level. The needs of the developing countries as regards space technology education may broadly be put into two categories: to raise their knowledge of space technology which requires hard work and teamwork skills, and to transfer and domesticate space technology while minimizing the costs and maximizing its effectiveness. The requirements of such space education system, which include research facilities, courses, and student projects are then defined using a model drawn from the space education systems in universities in North America and Europe that has been modified to include the above-mentioned needs. Three design concepts have been considered and synthesized through functional analysis. The first one is Modular and Detail Study which helps students specialize in a particular area in space technology. Second is referred to as Integrated and Interdisciplinary Study which focuses on understanding and development of space systems. Finally, the third concept which has been chosen for the purpose of this study, is a combination of the other two, categorizing the required curriculum into seven modules, setting aside space applications. This helps students to not only specialize in one of these modules but also to get hands-on experience in a real space project through participation in summer group projects and also working in space systems laboratories or choose and write a thesis based on experiences gained through an internship program. © 2010 Elsevier Ltd. All rights reserved.


Kianpour E.,University of Zagreb | Sidik N.A.C.,University of Zagreb | Bozorg M.A.S.M.,Iranian Space Agency ISA
Applied Mechanics and Materials | Year: 2012

This study was carried out to investigate the effects of different cooling holes configurations on the thermal field characteristics inside a combustor simulator. In this research, a three-dimensional presentation of a true Pratt and Whitney aero-engine was simulated and analyzed. This combustor simulator combined the interaction of two rows of dilution jets, which were staggered in the stream wise direction and aligned in the span wise direction. The findings of the study indicate that the thickness of the film-cooling layer was thicker for the greater penetration depth. Furthermore, for the combustor simulator with more cooling holes, the temperature near the wall and between the jets was slightly increased. Also at the leading edge of the jet, the gradients of temperature were quite high at the jet-mainstream interface. © (2012) Trans Tech Publications, Switzerland.


Kianpour E.,University of Zagreb | Sidik N.A.C.,University of Zagreb | Bozorg M.A.S.M.,Iranian Space Agency ISA
Jurnal Teknologi (Sciences and Engineering) | Year: 2012

This study was carried out in order to extend database knowledge about the flow field characteristics and define the various flow field contours inside a combustor simulator. The modern gas turbine industries try to get higher engine efficiencies. Brayton cycle is a key to achieve this purpose. According to this cycle industries should increase the turbine inlet temperature to get more engine efficiency and power. However the turbine inlet temperature increasing creates an extremely harsh environment for the downstream critical components such as turbine vanes. In this research a three-dimensional representation of a true Pratt and Whitney aero-engine which studied before in Virginia University was simulated and analyzed to collect essential data. This combustor simulator combined the interaction of two rows of dilution jets, which were staggered in the stream wise direction and aligned in the span wise direction, with that of filmcooling along the combustor liner walls. The overall findings of the study indicate that three-component velocity measurements showed the dilution jet-mainstream interaction produced shear forces and as a result a counter-rotating vortex pair was created. The highest turbulent kinetic energy was found at the top of recirculating region due to the interaction of the second row of dilution jets and mainstream flow. Furthermore, the centers of the counter-rotating vortex pair were spread relatively far apart due to the opposing dilution jets. Along the dilution jet centerline, negative stream wise velocities were measured indicating the recirculation region just downstream of the jet. Into the combustor exit, the acceleration of the flow increased and thereby the uniformity of the velocity profile enhancement was found as well. © 2012 Penerbit UTM Press.


Kianpour E.,University of Technology Malaysia | Sidik N.A.C.,University of Technology Malaysia | Bozorg M.A.S.M.,Iranian Space Agency ISA
International Journal of Heat and Mass Transfer | Year: 2013

This study was accomplished in order to investigate the effects of different cooling hole configurations on the thermal and flow field characteristics inside a combustor simulator. By using the well-known Brayton cycle, great turbine industries try to extend the inlet temperature and augment engine performance. However the turbine inlet temperature increment creates an extremely harsh environment for the downstream components of the combustor. In this research a three-dimensional representation of Pratt and Whitney aero-engine was simulated and analysed with a commercial finite volume package FLUENT 6.2 to gain fundamental data. The current study has been performed with Reynolds-averaged Navier-Stokes turbulence model (RANS) on internal cooling passages. This combustor simulator combined the interaction of two rows of dilution jets, which were staggered in the streamwise direction and aligned in the span wise direction, with that of film-cooling along the combustor liner walls. The entire findings of the study declare that the greater penetration depth, the thicker the film-cooling layers. Furthermore, in the combustor simulator with more cooling holes, the temperature near the wall and between the jets was slightly increased. Also at the leading edge of the jet, and at the jet-mainstream interface, the gradients of temperature were quite high. © 2013 Elsevier Ltd. All rights reserved.


Shekoofa O.,Iranian Space Agency ISA
RAST 2011 - Proceedings of 5th International Conference on Recent Advances in Space Technologies | Year: 2011

Solar arrays are the power source for the majority of space missions. They are the reason for many anomalies and failures in the electrical power subsystem, because they have to operate in a very harsh environmental condition. Undergoing to such sever conditions for generally long space mission life times is capable of degrading or damaging almost any parts of the solar arrays. Therefore it is quite necessary to do the qualification tests on the space solar cells and panels as much as complete and accurate as possible. Various standards have been developed by different space organizations in order to improve the level of quality of solar arrays and to assure the consumers about the reliability of these expensive products. In this paper some of the standards and procedures developed by ISO, AIAA, NASA and ECSS are discussed according to their methods and requirements. © 2011 IEEE.

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