Airship Design Research Articles

Preliminary Sizing of High-Altitude Airships Featuring Atmospheric Ionic Thrusters: An Initial Feasibility Assessment

When it comes to computing the values of variables defining the preliminary sizing of an airship, a few standardized approaches are available in the existing literature. However, when including a disruptive technology in the design is required, sizing procedures need to be amended, so as to be able to deal with the features of any additional novel item. This is the case of atmospheric ionic thrusters, a promising propulsive technology based on electric power, where thrusters feature no moving parts and are relatively cheap to manufacture. The present contribution proposes modifications to an existing airship design technique, originally conceived accounting for standard electro-mechanical thrusters, so as to cope with the specific features of new atmospheric ionic thrusters. After introducing this design procedure in detail, its potential is tested by showing results from feasibility studies on an example airship intended for a high-altitude mission. Concurrently, the so-obtained results allow the demonstration of the sizing features corresponding to the adoption of atmospheric ionic thrusters at the current level of technology, comparing them to what is obtained for the same mission when employing a standard electro-mechanical propulsion system.

Architecture Preliminary Design and Trade-Off Optimization of Stratospheric Airship Based on MBSE

System architecture design is crucial for forward design in aerostat system engineering, yet a comprehensive research framework has been lacking. This paper presents a new method for stratospheric airship architecture preliminary design and optimization trade-off, grounded in Model-Based Systems Engineering (MBSE) theory. Firstly, a requirement analysis for a stratospheric airship is conducted using SysML, leading to the analysis and acquisition of the airship’s mission architecture design. Additionally, a multidisciplinary coupling simulation platform is developed with MATLAB, and the architecture preliminary design’s Pareto front is derived using the NSGA-II algorithm. Finally, based on the Pareto optimization set, the TOPSIS algorithm is applied to derive the optimal architecture preliminary design scheme for the airship. The optimization results validate the accuracy of the architecture preliminary design obtained from the requirement analysis, the reliability of the multidisciplinary coupling simulation platform, and the feasibility of the optimization algorithms. This comprehensive study spans the requirement analysis to the optimal architecture scheme, providing theoretical reference and design guidance for the forward design of airship systems engineering.

Numerical simulation of fluid-thermal-structural coupling characteristics of stratospheric non-rigid airship

The voluminous stratospheric non-rigid airship is very sensitive to the external thermal environment. The temperature change of internal gas caused by the variation in the external thermal environment and wind speed will lead to a change in the shape and buoyancy of the airship, thereby affecting its flight control. The traditional static analysis method is difficult to accurately reflect this fluid-thermal-structural coupling process. In this paper, the iterative analysis method was established for the fluid-thermal-structural coupling effect of stratospheric non-rigid airship based on the models of fluid, thermal, and structural deformation. Considering the load such as the internal thermal effect and external flow field of the airship, the simulation of the thermo-induced structural deformation effect was conducted using Fluent and Abaqus software. The influence of local time and external wind speed on the structural deformation, volume, and equilibrium altitude of the airship was analyzed. The results demonstrate that, at low wind speed, the influence of aerodynamic pressure on the deformation of the airship is negligible. However, a great amount of heat is carried away by the wind, then the structural deformation caused by internal and external pressure difference is alleviated and the equilibrium altitude of the airship change obviously. This can serve as a guideline for the design and flight test of the long-endurance stratospheric non-rigid airship.

Variational Method-Based Trajectory Optimization for Hybrid Airships

Hybrid airships, combining aerodynamic lift and buoyant lift, are efficient near-space aircraft for scientific exploration, observation, and surveillance. Compared to conventional airplanes and airships, hybrid airships offer unique advantages, including stationary hovering and rapid deployment. Due to the different task requirements and strong coupling between flight and environment, trajectory-optimization methods for traditional aircraft are difficult to apply to hybrid airships directly. We propose a trajectory-optimization model based on the variational method to calculate the optimal time and energy paths under weak, uniform, and latitudinal linear wind fields. Our model shows that the influencing factors for the optimization path can be categorized into three types: airship design parameters, wind field parameters, and departure parameters. The result indicates that the optimal time paths are generally straight lines, and the optimal energy paths are piecewise curves with a 24-h cycle under typical hybrid airship design parameters. This work has provided new insight into the trajectory optimization and parameter design of future hybrid airships.

Hexa-Propeller Airship for Environmental Surveillance and Monitoring in Amazon Rainforest

This paper proposes a new kind of airship actuator configuration for surveillance and environmental monitoring missions. We present the design and application of a six-propeller electrical airship (Noamini) with independent tilting propellers, allowing improved and flexible maneuverability. The vehicle has different combinations of differential propulsion and can be used in a two-, four- or six-motor configuration. We developed a high-fidelity airship simulator for the Noamini airship, which was used to test and validate a control/guidance approach. Incremental Nonlinear Dynamic Inversion (INDI) is used for the velocity/attitude control to follow a high-level L1 guidance reference in a simulated waypoint-tracking mission with wind and turbulence. The proposed framework will be soon implemented in the onboard control system of the Noamini, an autonomous airship for environmental monitoring and surveillance applications.

Рассредоточенный нагрев гелия в беспилотном дирижабле сельскохозяйственного назначения

In modern agricultural production, unmanned aerial vehicles are capable of solving many tasks. It is expedient to use airships to perform long technological operations above the ground. To justify the need for the dispersed heating of helium in the working chamber of the airship, the authors considered the influence of the ratio of the volumes occupied by heated and cold helium in the working chamber of the airship, as well as the influence of the helium temperature on the lifting force. Calculations have shown that the dispersed heating of helium causes an accelerated change in its density, provides a reduction in the energy consumption for heating, and reduces the requirements for the thermal strength of the envelope. It is shown that distributed heating of helium in the whole working chamber of the airship has a number of advantages over local heating. In the proposed design of the unmanned airship, the technical implementation of the distributed heating of helium is achieved by means of an electrical heating device, the conductive elements of which are placed throughout the working chamber on supports made of light dielectric material. To increase the heating efficiency, the inner surface of the envelope is covered with a reflector made of thin basalt wool foil. The vertical maneuvering of the airship is automatically maintained by the control unit by connecting an electric heating device depending on the helium temperature and the ambient temperature.

Mismatch loss analysis of solar array output power on stratospheric airship during flight

Stratospheric airships are long-endurance aerostats and have broad applications. All of the energy required for their operation is obtained from solar radiation, which makes accurate calculation of the energy output from the solar array crucial to the design and flight planning of the airships. However, the status of each photovoltaic module in the solar array may differ due to the airship curvature, resulting in mismatch losses and lowered output power, which has not been widely studied. In this paper, an irradiation model and a thermal model are established based on the actual arrangement of the modules. The output power model is established considering the non-uniform radiation in the array. The mismatch losses of the array are analyzed under different flight conditions. The output power of the solar array is decreased by up to 31.6% compared to the ideal state. Moreover, the proportion of mismatch losses increases with latitude, but the maximum mismatch loss power occurs at mid-latitudes. Then, an array reconfiguration method is proposed based on the irradiance dispersion index and position dispersion index. The reconfigured array increases output power by 11.5% and can maintain energy balance in continuous flight. The results can be used to correct the overestimation of the output power during the airship design or to guide the configuration of the solar array.

A parametric design approach for multi-lobed hybrid airships

AbstractIn recent years, there has been an increasing interest in the research and development of hybrid airships for various applications. Airship design involves multiple design parameters from various disciplines that interact mutually. Existing design methodologies, however, are often limited to fixed shapes and geometry. This paper provides a comprehensive parametric design approach for the sizing of multi-lobed hybrid air vehicles for low- and high-altitude applications. The proposed design techniques are robust so that the designer has the freedom to change the number of lobes, the relative location of lobes, the envelope profile, and the optimiser for the design optimisation process. The outcomes of the proposed methodology are envelope volume, wetted surface area, length and span of the envelope, sizing and layout of the solar array, and sizing and layout of the fins. The modeling techniques highlighted in this paper are very efficient for the design and optimisation of multi-lobed airships in the conceptual design phase with a large design exploration space. The robustness of the shape generation algorithms is tested on some of the standard envelope profiles of airships. The effect of the shape and geometry of the multi-lobed envelope on added mass is demonstrated through the added mass estimation using Boundary Element Method.

Mapping Relationships Between Airship Original Design and Stability Modes

In this paper, we study the influence of an original airship design on its stability modes. Based on the verified model of the YEZ-2A airship, the Sobol sensitivities are calculated to filter the design parameters. The airship hull length, the slenderness ratio of the airship hull, the exponent of the tail, the fin installation position on the hull, and the fin half-span are found to be of large influences on all stability modes, whereas the stability modes are comparatively insensitive to the exponent of the bow and the fin relative thickness. The empirical formulas for mapping relationships are fitted to the experimental data and are verified by both sensitivities and root locus diagrams. The empirical formulas representing the mapping relationships between the original design parameters and the stability mode parameters of the airship can be used as references to simplify and estimate the stability and performance in the preliminary design of the airship.

A decision support system for multi-stakeholder exploration of the airship design space

Although there have been oscillations in airship interest since their use in the early 1900s, technological advancements and the need for more flexible and environmentally friendly transportation modes have caused a stream of study and surge in airship development in recent years. For companies and governments to understand how airships can be incorporated into their fleets to fulfill new or existing mission types, system design space exploration is an important step in understanding airships, their uses, and their design parameters. A decision support system (DSS), Design Exploration of Lighter-Than-Air Systems (DELTAS), was developed to help stakeholders with this task. DELTAS allows users to design airships and missions to determine how a design will perform in the scenario. As airships are sensitive to elevation and altitude, wind and terrain can also be studied to see how they may affect a mission scenario. Simulations can also be run for a given mission to find the Pareto-optimal designs for user-defined ranges of high-level airship design parameters. A case study is provided that demonstrates how DELTAS can be used to explore the airship design space for a specified mission. This case study shows how a design of experiments is important to more thoroughly cover the design space and to find and understand the relationships between airship design variables that lead to optimal mission times and costs.

Multidisciplinary Optimization and Analysis of Stratospheric Airships Powered by Solar Arrays

Stratospheric airships have much potential in military and commercial applications. Design, analysis and optimization of stratospheric airships involves complex trade-off of different disciplines, and hence a multidisciplinary approach is essential. This paper describes a methodology coupling several disciplines and involving seven design variables to obtain the optimal design of a stratospheric airship powered by solar arrays. A numerical method is established to calculate the output power of the solar array in the optimization process. The optimal solutions are obtained using hybrid algorithms. The methodology can obtain the optimal envelope shape, solar array layout and other general configurations of subsystems. Results show that the methodology was able to achieve a solution with a 19.2% reduction in airship volume compared to the value being part of an arbitrary initial set of airship parameters. In addition, a comparative study is carried out to highlight the importance of considerations of solar array layouts and array circumferential location. Furthermore, detailed sensitivity analysis shows that operating parameters of latitudes, heading angles and average resisting wind speeds have significant effects on the airship design and solar array layouts.

Strength analysis of composite envelope structures considering the tension–shear coupling and cutting pattern effect

Various strength criteria have been extensively used in the structural design of stratospheric airships. However, it is still a critical challenge to accurately predict the failure strength for ensuring structural safety due to the complex mechanical behaviors of multi-layer composite envelope materials under various loading environments. This article thus aims to establish refined numerical models for the strength prediction of envelope structures. Firstly, the mechanical properties of envelope materials were tested and investigated comprehensively. The creative concept of tension–shear​ coupling is demonstrated by the shear constitutive relation and failure criterion. Secondly, with consideration of the cutting pattern effect originating from the manufacturing procedure, a new equal-diameter flattening method for cutting gores is proposed. Finally, inflation-bursting tests of spherical and ellipsoidal envelopes were conducted to validate the proposed refined numerical models. The maximum deviation of strengths predicted by the novel criterion is less than 8% for both envelope structures, indicating that the tension–shear effect plays a significant role in the failure mechanism of flexible thin-walled envelope structures.

Layout Analysis and Optimization of Airships with Thrust-Based Stability Augmentation

Despite offering often significant advantages with respect to other flying machines, especially in terms of flight endurance, airships are typically harder to control. Technological solutions borrowed from the realm of shipbuilding, such as bow thrusters, have been largely experimented with to the extent of increasing maneuverability. More recently, also thrust vectoring has appeared as an effective solution to ameliorate maneuverability. However, with an increasing interest for high-altitude airships (HAAs) and autonomous flight and the ensuing need to reduce weight and lifting performance, design simplicity is a desirable goal. Besides saving weight, it would reduce complexity and increase time between overhauls, in turn enabling longer missions. In this perspective, an airship layout based on a set of non-tilting thrusters, optimally placed to be employed for both propulsion and attitude control, appears particularly interesting. If sufficiently effective, such configurations would reduce the need for control surfaces on aerodynamic empennages and the corresponding actuators. Clearly, from an airship design perspective, the adoption of many smaller thrusters instead of a few larger ones allows a potentially significant departure from more classical airship layouts. Where on one side attractive, this solution unlocks a number of design variables—for instance, the number of thrusters, as well as their positioning in the general layout, mutual tilt angles, etc.—to be set according simultaneously to propulsion and attitude control goals. In this paper, we explore the effect of a set of configuration parameters defining three-thrusters and four-thrusters layout, trying to capture their impact on an aggregated measure of control performance. To this aim, at first a stability augmentation system (SAS) is designed so as to stabilize the airship making use of thrusters instead of aerodynamic surfaces. Then a non-linear model of the airship is employed to test the airship in a set of virtual simulation scenarios. The analysis is carried out in a parameterized fashion, changing the values of configuration parameters pertaining to the thrusters layout so as to understand their respective effects. In a later stage, the choice of the optimal design values (i.e., the optimal layout) related to the thrusters is demanded to an optimizer. The paper is concluded by showing the results on a complete numerical test case, drawing conclusions on the relevance of certain design parameters on the considered performance, and commenting the features of an optimal configuration.

On the Feasibility of a Launcher-Deployable High-Altitude Airship: Effects of Design Constraints in an Optimal Sizing Framework

When ground observation or signal relaying in the vicinity of an unfriendly operative scenario are of interest, such as for military actions or disaster relief, high-altitude airships (HAA) offer some technical benefits. Featuring a milder cost and higher deployment flexibility with respect to lower-Earth orbit satellites, these platforms, often baptized as high-altitude pseudo-satellites (HAPS), operate sufficiently far from the ground to provide better imaging coverage and farther-reaching signal relaying than standard low-flying systems, such as aircraft or helicopters. Despite the atmospheric conditions in the higher atmosphere, they offer stable airstreams and highly-predictable solar energy density, thus ideally giving the chance of smooth operation for a prolonged period of time. The design of airships for the task is often conditioned by the need to go through the lower layers of the atmosphere, featuring less predictable and often unstable aerodynamics, during the climb to the target altitude. With the aim of simultaneously largely increasing the ease and quickness of platform deployment, removing most of the design constraints for the HAPS induced by the crossing of the lower atmosphere, and thus allowing for the design of a machine best suited to matching optimal performance at altitude, the deployment of the HAA by means of a missile is an interesting concept. However, since the HAA platform should take the role of a launcher payload, the feasibility of the mission is subject to a careful negotiation of specification, such that the ensuing overall weight of the airship is as low as possible. A preliminary design technique for high-altitude airships is therefore introduced initially, customized to some features typical to missile-assisted deployment, but with the potential for broader applications. The proposed procedure bends itself to the inclusion in an optimal framework, with the aim of seeking a design solution automatically. A validation of the adopted models and assumptions on existing HAPS is proposed first. The design of the airship is then carried out in a parameterized fashion, highlighting the impact of operative and technological constraints on the resulting sizing solutions. This allows for the marking of the boundaries of the space of design solutions for a launcher-deployable airship.

A Novel Design and Implementation of an Autopilot Terrain-Following Airship

Unmanned Aerial vehicles (UAV) have been utilized in many application domains. UAVs (or Airships, e.g., Drones) have been adopted to explore resources (e.g., minerals). One of the main limitations of using such airships is that flying at a fixed altitude is based on GPS altitude information. In many applications, it is important to support the ‘terrain-following flying’ function for airships when deployed and utilized in areas where the terrain is not flat but bumpy and steep (for example, in mountains areas in South Korea). This paper proposed a novel architecture of an airship autopilot system with three main contributions: First, the proposed architecture is designed to support a terrain-following function using a laser range finder (which continuously identifies the distance between an airship and terrain). Second, the proposed system provides two new algorithms for path and terrain-following functions for the proposed architecture. Third, this work designed and implemented a prototype airship and autopilot system to validate the proposed method. As a result, the proposed airship design and algorithm can guarantee a high-quality data collection (e.g., magnetic data) and demonstrate the benefits of the proposed approach with the experimental results based on real-flight operation in a test area.

Basic Problems Research in Stratospheric Airship Design

Basic Problems Research in Stratospheric Airship Design

Design and analysis of hybrid electric multi-lobed airship for cargo transportation

Though a lot of curiosity has been developed towards a sustainable mode of cargo transportation, multi-lobed hybrid airships are touted to be a viable alternative to the conventional aircraft. The advantages of these Lighter Than Air (LTA) vehicles can further be boosted by incorporating a renewable source of energy. The requirements of high power in cargo airships and the current technological barriers call for the development of a hybrid propulsion system that can couple the best of both conventional and electric propulsion. The electric propulsion system is established by integrating solar arrays with fuel cells, which is then combined with conventional engines in a parallel power train architecture ensuring minimum transfer of energy and compact size. A solar irradiance model is adopted, to evaluate the amount of energy generated by the solar arrays installed over the airship envelope. A multi-lobed hybrid airship model is presented whose aerodynamic characteristics are obtained using computational fluid dynamic tools, which are then utilized to evaluate the power requirements through flight performance analysis. The hybrid propulsion system is then modified in accord with the power needs of the hybrid airship. Finally, detailed weight distribution between hybrid-powered and conventional hybrid-airship is presented displaying significant reduction in fuel weight of ∼350 kg due to the hybrid propulsion system.

Conceptual Design and Feasibility Study of Winged Hybrid Airship

In recent years, hybrid airships have been identified as promising alternatives for high altitude, long endurance missions. In this study, a design methodology to study the feasibility of a winged hybrid airship powered by solar energy is presented. The proposed methodology involves five disciplines of the airship, viz., geometry, aerodynamics, environment, energy and structures that have been coupled in order to develop an optimum design which incorporates the maximum advantages of the modules. A total of fourteen design variables have been finalized, which are required to carry out the sizing of the envelope, wing, and solar panel layout. The Particle Swarm Optimization (PSO) algorithm is implemented to carry out optimization of a user-defined fitness function for given user-defined operating conditions. The optimization study is subjected to general constraints of weight balance and energy balance. Optimal solutions have been obtained for two different configurations. These are—conventional airship and winged hybrid airship. The solutions have been obtained for four different days of the year, in order to analyse any potential benefits and pitfalls of the two configurations for the varying conditions over the course of one year. The results obtained are generally found to be in excellent agreement with the imposed constraints. The winged hybrid airship configuration was found to have offered no significant benefits in comparison to the conventional configuration. The analysis of the key parameters and data values readily supports this conclusion.

Optimal Design of Green Tech Hybrid Electric Integrated Aircraft and Solar Disk Airships for Short Arctic Air Transport Corridors

The Ecology Decarburization issues decision may focus priority to the complex Design Analysis of the more Optimal Structure of the Large E-Aircraft and E-Airship for decrease of the Weight and Engine Power with Hybrid Electric Propulsion (HEP) systems are very actually today for Worldwide Ecology Program. The Method of Aircraft layout from the virtual mass center is given, which allows us to obtain the Aircraft layout from the conditions of Infrastructural Constraints in the terminal configurations of the Modern Air Transportation Infrastructure and IATA/ICAO Regulation. Calculate Method is proposed for the synthesis of new circuit solutions for an Aircraft passenger compartment and may be use to any Solar E-Dirigibles Projections future. A Geometrical representation of the concept of LHA with large passenger capacity made with a Drop-Shaped Fuselage in the Aerodynamic balancing Flying Wing Body Scheme is given. The new Body Plane E-Aircraft and Lighter-then-Air (LTA) Vehicles with cover of Solar Film Component Systems will be more innovation projections for High Safety Green Tech Air Transportation.

INTEGRATING SOCIAL IMPACT MEASURES INTO THE AIRSHIP DESIGN PROCESS

AbstractEngineered products have economic, environmental, and social impacts, which comprise the major dimensions of sustainability. This paper seeks to determine the interaction between design parameters when the social impacts are incorporated into the design process. Social impact evaluation is increasing in importance similar to what has happened with environmental impact consideration in recent years in the design of engineered products. Concurrently, research into new airship design has increased, however airships have yet to be reintroduced at a large scale and for a range of applications in society. Although airships have the potential for positive environmental and economic impacts, the social impacts are still rarely considered. This paper presents a case study of the hypothetical introduction of airships in the Amazon to help local farmers transport their produce to market. It explores the design space in terms of the airship's social impacts connected to the design parameters. The social impacts are found to be dependent not only on the social factors and airship design parameters, but also on the farmer-airship system, suggesting that socio-technical systems design will benefit from integrated social impact metric analysis.