Aerospace Science and Technology
A Fuzzy Fast Terminal Approach for Tracking a Probe Around an Asteroid

Mahsa Azadmanesh; Jafar Roshanian; Mostafa Hassanalian

Articles in Press, Accepted Manuscript, Available Online from 31 December 2022

https://doi.org/10.22034/jast.2022.362213.1131

Abstract
  This paper employs the fast terminal sliding mode control with the sign and the saturation function to track the landing trajectory of a probe on an asteroid and to further improve the dynamic tracking performance. Then the controller is enhanced by adding the fuzzy control to both fast terminals. To ...  Read More

Aerospace Science and Technology
Numerical Study of the Effect of Tip Clearance and Rotor-Stator Distance on the Performance of an Axial Turbine

Amir Akbari; Hossein Khaleghi

Articles in Press, Accepted Manuscript, Available Online from 25 January 2023

https://doi.org/10.22034/jast.2023.295476.1098

Abstract
  The use of unshrouded turbine rotor blades can considerably reduce the weight of an aero engine. However, in an unshrouded high-pressure turbine, the tip leakage flow generates about 30% of the turbine total loss. Another factor which affects the loss in axial-flow turbines, is the axial distance between ...  Read More

Aerospace Science and Technology
Optimal Round Trip Path-Planning of An Aerial Robot by Consideration of Geometric Constraints of Obstacles

Shayan Dehkhoda; Mohammad-Ali Amiri Atashgah

Articles in Press, Accepted Manuscript, Available Online from 31 January 2023

https://doi.org/10.22034/jast.2023.326735.1112

Abstract
  This paper is dedicated to the optimal path-planning of a quadrotor to deliver the goods in the form of a round-trip mission. At first, quadrotor modeling is performed by the Newton-Euler method and then the problem is formulated as an optimal control effort problem. Then, by discretization of the equations ...  Read More

Aerospace Science and Technology
Guidance law design for the final stage of the orbit injection problem

Morteza Sharafi; Mahdi Jafari; mojtaba alavipour

Articles in Press, Accepted Manuscript, Available Online from 05 May 2023

https://doi.org/10.22034/jast.2023.388139.1145

Abstract
  In this paper, optimal guidance law design considering fixed final state and time for the final phase a spacecraft or launch vehicle is investigated and studied. This guidance law, not only satisfied a specific optimality criterion, but it also has the least sensitivity to the initial state’s deviations; ...  Read More

Aerospace Science and Technology
Success of the Hybrid Genetic and Particle Swarm Algorithm for a Return Spacecraft from the Atmosphere with an Optimal Trajectory Design Approach to Reduce Aerodynamic Heat Transfer

Alireza Ekrami Kivaj; Alireza Novinzadeh; farshad pazooki; Ali Mahmoodi

Articles in Press, Accepted Manuscript, Available Online from 07 May 2023

https://doi.org/10.22034/jast.2023.375858.1138

Abstract
  This study aims to investigate the spacecraft returning from the atmosphere. Due to high speed, prolonged flight duration, and numerical sensitivity, returning from the atmosphere is regarded as one of the more challenging tasks in route design. Our suborbital system is subjected to a substantial thermal ...  Read More

Aerospace Science and Technology
On the Effects of Stiffness Ratio in Nonlinear Aeroelastic Stability of a Folding Wing

Sayed Hossein Moravej Barzani; Mahdi Mortazavi; Hossein Shahverdi

Articles in Press, Accepted Manuscript, Available Online from 22 May 2023

https://doi.org/10.22034/jast.2023.396484.1149

Abstract
  In this paper, the effects caused by the combination of folding angles simultaneously with changing the stiffness ratio of different parts of a folding wing are investigated. The geometrically exact fully intrinsic equations are employed to simulated the wing nonlinear dynamic behavior. The important ...  Read More