Modelling the effect of changing design fineness ratio of an airship on its aerodynamic lift and drag performance

Jalasabri, Jafirdaus; Romli, Fairuz Izzuddin; Harmin, Mohammad Yazdi

doi:10.1088/1757-899x/270/1/012002

Cited by 3 publications

(3 citation statements)

References 3 publications

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“…This is a widely-used method for investigating underlying relationships between interested variables, or in other words, to determine the causal effect of one variable to the other. Some examples of similar use of regression analysis method to this study include Japar et al, [22], Ni et al, [23] and Jalasabri et al, [24]. The regression analysis in this study is done using MINITAB statistical software and the resultant analysis of variance (ANOVA) table is presented in Table 2.…”

Section: Resultsmentioning

confidence: 99%

Optimization of a Blended-Wing-Body Unmanned Aerial Vehicle Design for Maximum Aerodynamic Lift-to-Drag Ratio

Romli

Sabri²,

Nasir³

2023

CFDL

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Although unmanned aerial vehicle (UAV) has found many applications in various fields, its operation has been constrained by its low flight endurance. To date, several design efforts are pursued to improve this performance and one of them is the exploration of blended-wing-body (BWB) design. In this study, parametric study is conducted on the BWB UAV design of Baseline-VII that is developed by Flight Technology and Test Center (FTTC), Universiti Teknologi MARA Shah Alam, Malaysia. The primary goal is to optimize the current Baseline-VII design for maximum lift-to-drag ratio, which in turn implies a higher flight endurance. Three design parameters are considered: inboard wing sweep angle, outboard wing sweep angle and also inboard wing span. A full-factorial design of experiments (DoE) is applied to set the total 27 design case settings for this study, with three different values considered for each design parameter: 10°, 25° and 50° for inboard and outboard wing sweep angles, and 200 mm, 300 mm and 400 mm for the inboard wing span. The computer-aided design (CAD) models for the design cases are constructed using Solidworks and the resultant aerodynamic lift-to-drag ratio is found through computational fluid dynamics (CFD) simulation analysis using ANSYS Fluent. The collected data is then statistically analysed using regression analysis in MINITAB to construct a representative regression model that aptly capture the effects of the varied design parameters on the design aerodynamic lift-to-drag ratio. Based on the results, it has been found that the maximum lift-to-drag ratio for the modified Baseline-VII UAV design is 2.8119, which is obtained with optimal settings of inboard wing sweep angle = 17.2727°, outboard wing sweep angle = 20.9091° and inboard wing span = 400 mm. This is about 28.4% increment of lift-to-drag ratio from the original Baseline-VII design.

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Section: Resultsmentioning

confidence: 99%

Optimization of a Blended-Wing-Body Unmanned Aerial Vehicle Design for Maximum Aerodynamic Lift-to-Drag Ratio

Romli

Sabri²,

Nasir³

2023

CFDL

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“…The design variables selected in this study are hull fineness ratio, fin area and fin position as they significantly affect the aerodynamic performance of the aerostat. The hull shape of the aerostat is kept constant, but its fineness ratio is taken as a design variable as it affects the drag coefficient (Hoerner, 1965; Jalasabri et al , 2017). The fin area is altered by changing the root chord and span of the fin, whereas the airfoil, sweep angle and tip to root chord ratio are constants.…”

Section: Methodsmentioning

confidence: 99%

The effect of hull fineness ratio and fin parameters on the optimization of tethered aerostat

Mahmood

Ismail

2021

AEAT

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Purpose This paper aims to optimize the mass of a tethered aerostat to achieve optimum hull volume, and fins to generate aerodynamic lift to reduce the blow-by. Design/methodology/approach The design code of aerostat involving structure, aerostatics, aerodynamics and stability has been developed using MATLAB®. The design code is used to obtain the baseline configuration for a tactical aerostat mission by using the statistical values of the hull fineness ratio and the fin parameters of in-service aerostats. The effect of the design variables that include the hull fineness ratio, fin area and fin position on the aerostat mass and blow-by is determined through sensitivity analysis. The aerostat is optimized with an objective function of minimization of mass for the bounded values of design variables and taking blow-by limit as a constraint. Findings This study reveals that the simultaneous optimization of the aerostat hull fineness ratio, fin area and fin position results in an improvement in the design. The aerostat design with optimum values of these parameters helps in a reduction in its size and mass without compromising the blow-by limits. Research limitations/implications This study has been conducted by keeping the hull shape constant by selecting standard National Physics Laboratory envelope shape. The aerodynamic model used in the design code is based on empirical relationships that can be improved in future studies that can use high fidelity aerodynamic models using CFD based surrogate models. Originality/value The previous studies on optimization of aerostats are limited to hull envelope shape only, whereas this paper presents the optimization of the hull and fin together. The optimized configuration obtained has a reduced mass and can operate within the specified blow-by limits.

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“…Hoerner (38) derived an empirical relation based on experimental data and the theory to estimate the volumetric drag coefficient of streamlined bodies using the fineness ratio (l/d) and the Reynolds number in a turbulent flow at zero angle-of-attack. Several studies (39,40,41) have demonstrated the impact of the fineness ratio on the aerodynamic characteristics of the vehicle body.…”

Section: Aerodynamic Modulementioning

confidence: 99%

A comparative study of conventional and tri-lobed stratospheric airships

Manikandan

Pant

2021

Aeronaut. j.

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The design and development of Stratospheric Airships for High-Altitude Long-Endurance missions (HALESAs) has generated interest worldwide. Conventional airships usually have a single-lobed axisymmetrical envelope shape. In contrast, several non-axisymmetric envelope configurations have been proposed for the HALESAs, such as flattened single lobed and multi lobed. This paper describes a methodology for carrying out a comparative analysis of a conventional HALESA and the multi-lobed HALESA designed for the same design mission. A sizing methodology which enables the estimation of its design parameters to meet some user-specified requirements has been developed for airships with envelopes of both these shapes. A Multidisciplinary Design Optimisation (MDO) approach has been followed in this methodology, which includes considerations from the disciplines of aerodynamics, energy, environment and structures. The study indicates that the envelope volume, solar array area and total mass of the single-lobed conventional airship are better than those of the tri-lobed HALESA. While the multi-lobed HALESA has the advantage of a flatter upper surface resulting in higher efficiency of the solar panels, the conventional airship has lower drag, which results in superior mission performance.

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Modelling the effect of changing design fineness ratio of an airship on its aerodynamic lift and drag performance

Cited by 3 publications

References 3 publications

Optimization of a Blended-Wing-Body Unmanned Aerial Vehicle Design for Maximum Aerodynamic Lift-to-Drag Ratio

Optimization of a Blended-Wing-Body Unmanned Aerial Vehicle Design for Maximum Aerodynamic Lift-to-Drag Ratio

The effect of hull fineness ratio and fin parameters on the optimization of tethered aerostat

A comparative study of conventional and tri-lobed stratospheric airships

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