Designing a Fault-Tolerant Control System for the Boeing 747

Reza Soltani Nezhad; Abolqasem Naghash

Volume 13, Issue 1 , June 2020, Pages 1-9

http://dx.doi.org/10.22034/jast.2020.119910

Abstract
  This article examines the fault tolerance control (FTC) system for the Boeing 747. to reach this goal, firstly 6 degrees of freedom equations are simulated and linearized by using dynamic inversion method. Then, the system is controlled by a linear proportional-integral-derivative controller. To control ...  Read More

Experimental Comparison of Thrust Performance of Two Low and Medium-Speed Motors by Wind Tunnels and Obtaining the Flight Time of a Specific Drone

A. Hossein Gholami; Mohammad Haeri; Ali Reza Doodman Tipi

Volume 13, Issue 1 , June 2020, Pages 10-17

http://dx.doi.org/10.22034/jast.2020.119909

Abstract
  With the advancement of science and technology, ultra-light drones with electric propulsion hold many applications. In these drones, the electric motor is the primary consumer of energy. Thus, having an accurate model of power consumption of the motor, propeller, and battery set can play an essential ...  Read More

Numerical Study of Changes in Length-to-Diameter Ratio of a Cylindrical Diffuser, Used in a Vacuum Test Stand

Ali Reza Nadri; Hamid Reza ُShidvash

Volume 13, Issue 1 , June 2020, Pages 18-25

http://dx.doi.org/10.22034/jast.2020.122051

Abstract
  The vacuum test stand simulates the space systems' engines with a high expansion ratio at high altitudes and vacuum pressure for static tests. This article investigates the flow stability in the diffuser to use in a vacuum stand. Several variables are essential in the operation of this system, including ...  Read More

Modeling of 9 Degrees of Parafoil Freedom through Transverse Displacement of Cargo Weight

Meghdad Torabinezhad; Fariborz Saghafi

Volume 13, Issue 1 , June 2020, Pages 26-38

http://dx.doi.org/10.22034/jast.2020.119913

Abstract
  Parafoil-cargo system, as a complex system, is used widely today and has various usages. This system is a polynomial complex whose components, have dynamic interactions and relative movements. The present study deals with the multibody modeling and simulation of nine degrees of freedom flight dynamics ...  Read More

Numerical Investigation of Aerodynamic Effects of Geometry and Sensor Distance on a Spherical Projectile

kosar Mokhtari; Alireza Naderi

Volume 13, Issue 1 , June 2020, Pages 39-47

http://dx.doi.org/10.22034/jast.2020.120341

Abstract
  The present study investigates the flow around two tandem spheres and their aerodynamic optimization. In a systematic view, the downstream sphere is regarded as the projectile and the upstream sphere is the sensor. The aim of this study is to find the most appropriate configuration with lowest drag force. ...  Read More

Simulation and Examination of Flow Characteristics of the Butterfly Valve

Fathollah Ommi; Hamidreza Khodayari; Zoheir Saboohi

Volume 13, Issue 1 , June 2020, Pages 47-56

http://dx.doi.org/10.22034/jast.2020.120343

Abstract
  Butterfly valves as control valves are used when a small pressure drop is required in the valve. The results of numerical studies of solving the incompressible flow equations around the butterfly valve in three dimensions are presented in this paper. ANSYS CFX commercial software is used to solve the ...  Read More

Calculation of Nonlinear Normal Modes Using EPFM Method

Maysam gelveh; S. Mojtaba Mosavi; Mohammad Homayoun Sadr

Volume 13, Issue 1 , June 2020, Pages 57-65

http://dx.doi.org/10.22034/jast.2020.122286

Abstract
  In the last decade, nonlinear normal modes have attracted the attention of many researchers, and many methods and algorithms have been proposed to calculate them. Among the proposed methods, the combination of the shooting method and the continuation of the periodic solution is the strongest methods. ...  Read More

GROWTH AND COLLAPSE OF A CAVITATION BUBBLE INSIDE A RIGID CYLINDER: EFFECT OF MEMBRANE TENSION

Amireh Norbaskhsh

Volume 13, Issue 1 , June 2020, Pages 66-76

http://dx.doi.org/10.22034/jast.2020.122288

Abstract
   In this paper, growth and collapse of a cavitation bubble inside a rigid cylinder with a compliant coating (a model of human’s vessels) are studied using Boundary Integral Equation and Finite Difference Methods. The fluid flow is treated as a potential flow and Boundary Integral Equation ...  Read More

Aerospace Science and Technology
Neural Network Backstepping control of a reentry vehicle in the presence of uncertainties

M. Khoshnood; H. Ashoori

Volume 13, Issue 1 , June 2020, Pages 77-81

http://dx.doi.org/10.22034/jast.2020.119916

Abstract
  In this paper, a neural network backstepping controller is designed for the control of a  reentry vehicle. The backstepping control system is applied to the nonlinear six degree of freedom dynamics of the reentry vehicle for tracking the desired input. The neural network is used for estimation of ...  Read More

Optimal Flight Trajectory Planning using Improved Evolutionary Method for UCAV Navigation in 3D Constrained Environments

R.Ali Abbaspour; A.A. Heidari

Volume 13, Issue 1 , June 2020, Pages 83-89

http://dx.doi.org/10.22034/jast.2020.120342

Abstract
  This article addresses a new approach to 3D path planning of UCAVs. To solve this NP-hard problem, imperialist competitive algorithm (ICA) was extended for path planning problem. This research is related to finding optimal trajectories before UCAV missions. Developed planner provides 3D optimal paths ...  Read More

Experimental Investigation of The Geometric Properties of Different Rotor Blades for Controlling the Wingtip Vortex

Mostafa Kazemi; parisa Ghanoni; Mahdi Sharifi; Mahmood Mani

Volume 13, Issue 1 , June 2020, Pages 89-94

http://dx.doi.org/10.22034/jast.2020.119915

Abstract
  This study focuses on using rotor blade turbine winglets for the purpose of controlling the wingtip vortex in airplanes. The aim of the study is to investigate the effective geometric properties of the rotor blades that are used as winglets, as well as experimental evaluation of their effects on drag, ...  Read More

Optimal Guidance of a Reentry Vehicle Based on Online Trajectory Optimization

Reza Jamilnieya

Volume 13, Issue 1 , June 2020, Pages 95-105

http://dx.doi.org/10.22034/jast.2020.119917

Abstract
  In this paper, a new method for optimal guidance in the atmospheric return phase is proposed. This guidance method is based on instantaneous and online trajectory optimization in which optimal guidance commands are obtained from sequential solving of optimal control problems. In order to solve optimal ...  Read More