In-Bore Yaw Effects on Lateral Throw-off and Aerodynamic Jump Behavior for Small Caliber Projectiles Firing Sidewise From Air Vehicles

2011 ◽  
Vol 78 (5) ◽  
Author(s):  
Dimitrios N. Gkritzapis ◽  
Elias E. Panagiotopoulos
Keyword(s):  
Motion Analysis ◽  
Mass Distribution ◽  
Simulation Modeling ◽  
Flight Simulation ◽  
Weapon System ◽  
Flight Trajectory ◽  
Free Flight ◽  
Air Vehicles

The present study investigates the effects of in bore-yaw phenomenon on lateral throw-off and aerodynamic jump behavior for small caliber rotational symmetric (both in configuration and mass distribution) projectiles launched horizontally at supersonic firing speeds and various altitudes from high-subsonic air vehicles. The ammunition used is the caliber .50 API M8 bullet type firing from M2 machine automatic gun. The projectile is considered to be eccentrically engraved, tilted as it enters the rifling, and it is assumed that the tilt persists throughout its passage through the rifled barrel of the used weapon system. The modified linear 6-DOF flight simulation modeling is applied for the bullet free-flight trajectory predictions. The coupled epicyclic pitching and yawing motion analysis for the first 100 m of the examined trajectories are taken into account.

scholarly journals Engineering Comprehensive Model of Complex Wind Fields for Flight Simulation

Aerospace ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 145
Author(s):  
Jianwei Chen ◽  
Liangming Wang ◽  
Jian Fu ◽  
Zhiwei Yang
Keyword(s):  
Wind Field ◽  
Three Dimensional ◽  
Great Influence ◽  
Spatial Location ◽  
Flight Simulation ◽  
Comprehensive Model ◽  
Flight Trajectory ◽  
Wind Fields ◽  
Wind Field Simulation ◽  
Low Level Jet

A complex wind field refers to the typical atmospheric disturbance phenomena existing in nature that have a great influence on the flight of aircrafts. Aimed at the issues involving large volume of data, complex computations and a single model in the current wind field simulation approaches for flight environments, based on the essential principles of fluid mechanics, in this paper, wind field models for two kinds of wind shear such as micro-downburst and low-level jet plus three-dimensional atmospheric turbulence are established. The validity of the models is verified by comparing the simulation results from existing wind field models and the measured data. Based on the principle of vector superposition, three wind field models are combined in the ground coordinate system, and a comprehensive model of complex wind fields is established with spatial location as the input and wind velocity as the output. The model is applied to the simulated flight of a rocket projectile, and the change in the rocket projectile’s flight attitude and flight trajectory under different wind fields is analyzed. The results indicate that the comprehensive model established herein can reasonably and efficiently reflect the influence of various complex wind field environments on the flight process of aircrafts, and that the model is simple, extensible, and convenient to use.

scholarly journals Aerial course stabilization is impaired in motion-blind flies

2020 ◽  
Author(s):  
Maria-Bianca Leonte ◽  
Aljoscha Leonhardt ◽  
Alexander Borst ◽  
Alex S. Mauss
Keyword(s):  
Motion Detection ◽  
Visual Motion ◽  
Flight Performance ◽  
Wild Type ◽  
Flight Trajectory ◽  
Free Flight ◽  
Motion Vision ◽  
Circling Behaviour ◽  
Course Control ◽  
Self Motion

AbstractVisual motion detection is among the best understood neuronal computations. One assumed behavioural role is to detect self-motion and to counteract involuntary course deviations, extensively investigated in tethered walking or flying flies. In free flight, however, any deviation from a straight course is signalled by both the visual system as well as by proprioceptive mechanoreceptors called ‘halteres’, which are the equivalent of the vestibular system in vertebrates. Therefore, it is yet unclear to what extent motion vision contributes to course control, or whether straight flight is completely controlled by proprioceptive feedback from the halteres. To answer these questions, we genetically rendered flies motion-blind by blocking their primary motion-sensitive neurons and quantified their free-flight performance. We found that such flies have difficulties maintaining a straight flight trajectory, much like control flies in the dark. By unilateral wing clipping, we generated an asymmetry in propulsory force and tested the ability of flies to compensate for this perturbation. While wild-type flies showed a remarkable level of compensation, motion-blind animals exhibited pronounced circling behaviour. Our results therefore unequivocally demonstrate that motion vision is necessary to fly straight under realistic conditions.

Multibody Modeling and Simulation of Monocopter Micro Air Vehicle

2015 ◽  
Vol 772 ◽  
pp. 401-409
Author(s):  
Mehrdad Ebrahimi Dormiyani ◽  
Afshin Banazadeh ◽  
Fariborz Saghafi
Keyword(s):  
Degrees Of Freedom ◽  
Initial Conditions ◽  
Model Simulation ◽  
Static Stability ◽  
Flight Simulation ◽  
Control Surface ◽  
Free Flight ◽  
Nonlinear Simulation ◽  
Multibody Model ◽  
Air Vehicle

In the current paper, seven degrees of freedom multibody model of a monocopter air vehicle is developed based on the Newton-Euler approach along with nonlinear simulation in different flight phases. Aerodynamic forces and moments are modeled using blade element momentum theory. The sole control surface is modeled like a conventional flap on a wing. Free flight simulation is performed in MATLAB Simulink environment to evaluate the behavior of the system and to demonstrate the effectiveness and applicability of the proposed model. Simulation results show harmonic oscillations in Euler angles, linear and angular velocities that are consistent with the physics and mathematical foundations. Static stability of the vehicle is evident in free flight by careful choice of initial conditions. The presented multibody model is useful for comparative study and design purposes.

Research on Simulation Modeling of Flight Aircraft Air under the Condition of Turbulent Flow

2014 ◽  
Vol 684 ◽  
pp. 165-168
Author(s):  
Yong Zhou Jiang ◽  
Yong Ji Lu ◽  
Yan Ding ◽  
Xiao Yan Yu
Keyword(s):  
Real Time ◽  
Simulation Modeling ◽  
Flight Simulation ◽  
Flight Simulator ◽  
Aircraft Structure ◽  
Atmospheric Disturbance ◽  
Real Time Simulation ◽  
Time Simulation ◽  
Simulation Based ◽  
Long Time

The flight process often in turbulence. Atmospheric turbulence causes flight bump, long time will cause damage to the aircraft structure fatigue. This paper establishes a model for atmospheric disturbance, flight simulation. Based on the aircraft through all kinds of atmospheric disturbance is studied. The use of embedded database and real-time simulation platform, built a run, in the PC machine can be used for dynamic model for real-time simulation of flight simulator.

scholarly journals Free-flight simulation of Sympetrum frequens hovering

2003 ◽  
Vol 2003.16 (0) ◽  
pp. 83-84
Author(s):  
Hirohisa ENOMOTO ◽  
Masaki HAMAMOTO ◽  
Toshiaki HISADA ◽  
Keita HARA ◽  
Yoshiji OHTA
Keyword(s):  
Flight Simulation ◽  
Free Flight ◽  
Sympetrum Frequens

scholarly journals Aerial course stabilization is impaired in motion-blind flies

2021 ◽  
Author(s):  
Maria-Bianca Leonte ◽  
Aljoscha Leonhardt ◽  
Alexander Borst ◽  
Alex S. Mauss
Keyword(s):  
Visual Motion ◽  
Flight Performance ◽  
Propulsive Force ◽  
Wild Type ◽  
Flight Trajectory ◽  
Free Flight ◽  
Motion Vision ◽  
Circling Behaviour ◽  
Course Control ◽  
Course Changes

Visual motion detection is among the best understood neuronal computations. As extensively investigated in tethered flies, visual motion signals are assumed to be crucial to detect and counteract involuntary course deviations. During free flight, however, course changes are also signalled by other sensory systems. Therefore, it is yet unclear to what extent motion vision contributes to course control. To address this question, we genetically rendered flies motion-blind by blocking their primary motion-sensitive neurons and quantified their free-flight performance. We found that such flies have difficulties maintaining a straight flight trajectory, much like unimpaired flies in the dark. By unilateral wing clipping, we generated an asymmetry in propulsive force and tested the ability of flies to compensate for this perturbation. While wild-type flies showed a remarkable level of compensation, motion-blind animals exhibited pronounced circling behaviour. Our results therefore directly confirm that motion vision is necessary to fly straight under realistic conditions.

Aircraft Free Flight Simulation in a Wind Tunnel

2014 ◽  
Vol 541-542 ◽  
pp. 1390-1393
Author(s):  
Atahir Elhashani ◽  
Adel Kurban ◽  
Marwa L. Agela
Keyword(s):  
Wind Tunnel ◽  
Pitch Angle ◽  
Pressure Sensors ◽  
Flight Simulation ◽  
Digital Data ◽  
Longitudinal Motion ◽  
Free Flight ◽  
Basic Algorithm ◽  
Analog To Digital ◽  
Mass Moment

The Unmanned Ariel Vehicle Model is Mounted in the Wind Tunnel. where its Longitudinal Motion of Electric Propeller was Developed and Simulated as a Free Aircraft Flight. the Numerical Values of the Aerodynamic Stability and Control Derivatives are Evaluated via the Digital Tornado Algorithm. this Evaluation is Carried out Based on the Geometric Parameters of the Airplane, Aircraft Center of Gravity and Mass Moment of Inertia. the Stability and Response of the Linearized Longitudinal Model of the Considered Aircraft are Tested and Investigated. the Onboard Computer is Implemented Based on a Microcontroller Pic16f877a, where the Pitch Angle and Speed of the Considered Free Flight Vehicle are Read Respectively by an Gyroscope and Pressure Sensors. and the Microcontroller Read these Signals via Analog to Digital Converter which are in Turns as a Serial Digital Data by Using of Universal Synchronous Asynchronous Receive Transmit. Apply the Personal Computer to Receive the Serial Signal through the PC RS232 Standard as Serial Data. where in the PC, the Visual Basic Algorithm is Written as well in Order to Display and Plot the Pitch Angle Airspeed Responses on the Screen. Finally, the Experimental Results of Aircraft Free Flight in Real Time are Obtained by Carrying out the Simulation in the Wind Tunnel.

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