Airship Aerodynamic Coefficients Estimation Based on Computational Method for Preliminary Design

Mendonça, Jefferson L.; Santos, Jonatas S.; Morales, Mauricio Andrés Varela; Góes, Luiz Carlos Sandoval; Stevanović, Stojan; Santana, Rodrigo A.

doi:10.2514/6.2019-2982

Cited by 5 publications

(3 citation statements)

References 7 publications

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“…Tao presented an approach based on system identification to obtain the derivatives of an LTA vehicle that is having swing oscillations 14 . Computational approaches for estimating the stability derivatives of LTA vehicles were also reported 15 .…”

Section: Introductionmentioning

confidence: 99%

Mathematical modelling of a single tethered aerostat using longitudinal stability derivatives

Sasidharan,

Velamati,

Mohammad

et al. 2024

Sci Rep

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Lighter-than-air (LTA) aerial vehicles such as airships and aerostats can be found in various strategic and commercial applications, primarily due to their capability to hover and stealth. The mathematical model of these vehicles helps in understanding their complex dynamics and designing and developing proper stabilisation systems for them. Stability derivatives have been used for developing mathematical models for heavier-than-air aerial vehicles since their introduction. This paper presents a methodology to develop a mathematical model of an aerostat based on stability derivatives. One of the major contributions of this study is the estimation of aerostat’s added mass terms expressed as longitudinal stability derivatives due to acceleration of the longitudinal motion variables. A longitudinally decoupled linear mathematical model of a single-tethered aerostat using stability derivatives is investigated in this study. A computational fluid dynamics (CFD)-based analysis of the 3D model of the vehicle is used to obtain the stability derivatives. The methodology presented considers the aerostat and tether models separately before coupling them to create the full model. The stability derivative analysis is carried out using ANSYS Fluent, and the coupled tethered aerostat model is investigated using MATLAB 2020. The negative pitch angle of the aerostat is caused by the selection of the pitching centre as the aerostat centre of volume instead of the tether confluence point. The tension force on the tether, which is proportional to the wind velocity, and aerostat velocity components are found to be stabilised within 200–400 s.

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Section: Introductionmentioning

confidence: 99%

Mathematical modelling of a single tethered aerostat using longitudinal stability derivatives

Sasidharan,

Velamati,

Mohammad

et al. 2024

Sci Rep

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show abstract

“…There are various methods by which we can estimate the parameters included in the aerodynamic model such as CFD based methods [8], experimental methods using wind tunnel [4,9] and analytical methods [10]. Computational Fluid Dynamics (CFD) tools can be used to extract the aerodynamic coefficients for airship geometries [11,12]. A method of extracting the force and moment coefficients of an airship using CFD and Fourier analysis is presented in [11].…”

Section: Introductionmentioning

confidence: 99%

“…Forced sinusoidal oscillations are used in the longitudinal direction to extract the force and moment coefficients. A specialised computational tool used for the aerodynamic coefficient extraction is presented in [12]. The major drawbacks of CFD based analysis are the inability to model the geometry accurately, computational cost and time taken for simulation.…”

Section: Introductionmentioning

confidence: 99%

Modelling and Simulation of Aerodynamic Parameters of an Airship

Anoop¹,

Murthy²

2020

Adv. sci. technol. eng. syst. j.

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The dynamic modelling of an airship is the primary requirement in designing and developing a control system for a particular application. Extracting/predicting/modelling the aerodynamic coefficients is a crucial step towards the modelling of an airship. There is a huge amount of literature on the aerodynamic modelling of airships which presents experimental as well as analytical methods. All these techniques require some experimental data such as the geometrical data, control derivatives, etc. In this work, we are investigating an analytical technique which can calculate the aerodynamic parameters for a high altitude airship. The complete airship model is implemented using the derived aerodynamic coefficients. A MATLAB R Simulink based simulation is used for the investigation. Nomenclature α Angle of attack, deg β Side slip angle, deg δ a Aileron deflection angle, deg δ e Elevator deflection angle, deg δ r Rudder deflection angle, deg η Throttle ratio γ, µ Angles along the wind axes, deg φ, θ, ψ Airship's Euler angles-roll, pitch and yaw, deg ρ Density of air, kg/m 3 b Wing span, m b z Point of action of buoyant force in z direction, m c mean aerodynamic chord, m C D , C L , C Y Coefficient of drag, lift and side force C l , C m , C n Coefficient of rolling moment, pitching moment and yawing moment d z Point of action of thrust in z direction, m I x , I y , I z Moment of inertia components about x, y and z axes, kg/m 2 I xz Product of inertia about y axis, kg/m 2 m Airship mass, kg m x , m y , m z Apparent mass components in the x,y and z axes, kg p, q, r Airship angular velocities along the roll, pitch and yaw axes, deg/s S Wing planform area, m 2 t, T Current simulation time and gust time period, s T m Maximum engine thrust, N u, v, w Airship linear velocities along the x,y and z body axes, m/s V Airship forward velocity, m/s V m , V g Mean wind and gust velocity, m/s x E , y E , z E Position coordinate in the earth frame, m CoG Centre of Gravity CoV Centre of Volume EOG Extreme Operating Gust LTA Lighter-Than Air

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Estimation of Stability Derivatives Due to Translational Motion of Various LTA Vehicles Using CFD

Anoop

Velamati

Janardhanan

et al. 2022

Lecture Notes in Mechanical Engineering

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Airship Aerodynamic Coefficients Estimation Based on Computational Method for Preliminary Design

Cited by 5 publications

References 7 publications

Mathematical modelling of a single tethered aerostat using longitudinal stability derivatives

Mathematical modelling of a single tethered aerostat using longitudinal stability derivatives

Modelling and Simulation of Aerodynamic Parameters of an Airship

Estimation of Stability Derivatives Due to Translational Motion of Various LTA Vehicles Using CFD

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