Search results

The purpose of this study is to present a methodology for parameters’ sensitivity analysis of solar-powered airplanes.

The study focuses on a preliminary design and parameters’ relations of a heavier-than-air, solar-powered, high-altitude long-endurance unmanned aerial vehicle. The methodology is founded on the balance of energy production and requirement. An analytic expression with four generalized parameters is derived to determine the airplane flying on the specific altitude. The four generalized parameters’ sensitivities on altitude are then analyzed. Finally, to demonstrate the methodology, a case study is given on the parameters’ sensitivity analysis of a prototype solar-powered airplane.

When using the presented methodology, the nighttime duration and the energy density of batteries are more sensitive on flight altitude of the prototype airplane.

It is not easy to design a solar-powered airplane to realize high-attitude and long-endurance flight. For the current state-of-art, it is a way to figure out the most critical parameters which need prior consideration and immediate development.

This paper provides an analytical methodology for analyzing the parameters’ sensitivities of solar-powered airplanes, which can benefit the preliminary design of a solar-powered airplane.

The purpose of this paper is to propose a methodology to determine the designing parameters for solar powered high‐altitude, long‐endurance (HALE) unmanned aerial vehicles (UAV).

By depicting solar power distribution on earth, along with the efficiencies analysis of photo‐voltaic cells (P‐cell) and lithium‐sulfur battery (LS‐battery), the influence of energy to concept design parameters is analyzed first. Second, the lift efficiency is determined from ground to 20 km for HALE UAV. Third, the methodology to determine design parameters for HALE UAV is generalized by analyzing the carrying ability of some famous HALE UAVs, such as Zephyr, Helios, and so on.

Energy is the key constraint on design of HALE UAV. The questions about where HALE UAVs are capable of operating and how long they could work can be answered according to power density distribution on earth. The total mass of HALE UAV can be divided into two parts: one is the constant mass, the other is the mass increasing with area of wing. The total mass can be estimated by the former one; the later one plays an important role in estimating wing load in the designing process.

The only way to enhance carrying ability of HALE UAVs is to redistribute their wing load: lighter structure materials and a better method to fix P‐cell with lighter fundus are the key technologies to enhance HALE UAVs’ carrying ability. At current technological levels, it is not easy to design a UAV to achieve the aim of high‐altitude long‐endurance.

This paper presents a very efficient and convenient method to determine the designing parameters of HALE UAV.

The purpose of this paper is to present the development of an optimal design framework for high altitude long endurance solar unmanned aerial vehicle. The proposed solar aircraft design framework provides a simple method to design solar aircraft for users of all levels of experience.

This design framework consists of algorithms and user interfaces for the design of experiments, optimization and mission analysis that includes aerodynamics, performance, solar energy, weight and flight distances.

The proposed sizing method produces the optimal solar aircraft that yields the minimum weight and satisfies the constraints such as the power balance, the night time energy balance and the lift coefficient limit.

The design conditions for the sizing process are given in terms of mission altitudes, flight dates, flight latitudes/longitudes and design factors for the aircraft configuration.

The framework environment is light and easily accessible as it is implemented using open programs without the use of any expensive commercial tools or in-house programs. In addition, this study presents a sizing method for solar aircraft as traditional sizing methods fail to reflect their unique features.

Solar aircraft can be used in place of a satellite and introduce many advantages. The solar aircraft is much cheaper than the conventional satellite, which costs approximately $200-300m. It operates at a closer altitude to the ground and allows for a better visual inspection. It also provides greater flexibility of missions and covers a wider range of applications.

This study presents the implementation of a function that yields optimized flight performance under the given mission conditions, such as climb, cruise and descent for a solar aircraft.

The aviation industry has started environment friendly and also conventional energy independent alternative energy dependent designs to reduce negative impacts on the nature and to maintain its future activities in a clear, renewable and sustainable way. One possible solution proposed is solar energy. Solar-powered aerial vehicles are seen as key solutions to reduce global warming effects. This study aims to simulate a mathematical model of a solar powered DC motor of an UAV on MATLAB/Simulink environment.

Maximum power point tracking (MPPT) is a critical term in photovoltaic (PV) array systems to provide the maximum power output to the related systems under certain conditions. In this paper, one of the popular MPPT techniques, “Incremental Conductance”, is simulated with solar-powered DC motor for an UAV design on MATLAB/Simulink.

The cascade structure (PV cell, MPPT, buck converter and DC motor models) is simulated and tested under various irradiance values, and results are compared to the DC motor technical data. As a result of that, mathematical model simulation results are overlapped with motor technical reference values in spite of irradiance changes.

It is suggested to be used in real time applications for future developments.

Different from other solar-powered DC motor literature works, a solar-powered DC motor mathematical model of an UAV is designed and simulated on MATLAB/Simulink environment. To adjust the maximum power output at the solar cell, incremental conductance MPPT technique is preferred and a buck converter structure is connected between MPPT and DC motor mathematical model. It is suggested to be used in solar-powered UAV designs for future developments.

This paper aims to describe the enhancement of the numerical method for conceptual phase of electric aircraft design.

The algorithm provides a balance between lift force and weight of the aircraft, together with drag and thrust force equilibrium, while modifying design variables. Wing geometry adjustment, mass correction and performance estimation are performed in an iterative process.

Aircraft numerical model, which is most often very simplified, has a number of new improvements. This enables to make more accurate analyses and to show relationships between design parameters and aircraft performance.

The presented approach can improve design results.

The new methodology, which includes enhanced numerical models for conceptual design, has not been presented before.

Aircraft structure mass estimation is a very important issue in aerospace. Multiple methods of different fidelity are available, which give results with varying accuracy. Sometimes these methods are giving a high discrepancy of estimated mass compared to the real mass of the structure. The discrepancy is especially noticeable in the case of small aircraft with a composite structure. Their mass properties highly depend not only on the material but also on technology and the human factor. Moreover, methods of mass estimation for unmanned aerial vehicle (UAV) platforms are even less established and examined. The purpose of this paper is to present and discuss various methods of mass estimation.

The paper presents different procedures of mass estimation for small UAVs with a composite structure. Beginning from the simplest one, where mass is estimated basing on a single equation and finishing with a mass estimation based on finite element method model and three-dimensional computer-aided design model. The results from all methods are compared with the airworthy aircraft and conclusions are discussed.

Mass of flying aircraft was estimated with different methods and compared. It revealed levels of accuracy of the investigated methods. Moreover, the influence on structure mass of human factor, glueing and painting is underlined.

Mass of the structure is a key factor in aerospace, which influences the performance of the aircraft. Thorough knowledge about the accuracy of the mass estimation methods and possible sources of discrepancies in mass analyses provides an essential tool for designers, which can be used with confidence and allows for the development of new cutting-edge constructions.

There are very few comparisons of mass estimation methods with an actual mass of manufactured and functional airframes. Additionally, mass estimation inaccuracies based on technological issues are presented, which is seldom done.

The authors present the impact of the coronavirus disease 2019 (COVID-19) pandemic on community lifelines. The state machinery has several departments to secure essential lifelines during disasters and epidemics. Many countries have formed national disaster management authorities to deal with manmade and natural disasters. Typical lifelines include food, water, safety and security, continuity of services, medicines and healthcare equipment, gas, oil and electricity supplies, telecommunication services, transportation means and education system. Supply chain systems are often affected by disasters, which should have alternative sources and routes. Doctors, nurses and medics are front-line soldiers against diseases during pandemics.

The COVID-19 pandemic has revealed how much we all are connected yet unprepared for natural disasters. Political leaders prioritize infrastructures, education but overlook the health sector. During the recent pandemic, developed countries faced more mortalities, fatalities and casualties than developing countries. This work surveys the impact of the COVID-19 pandemic on health, energy, environment, industry, education and food supply lines.

The COVID-19 pandemic caused 7% reductions in greenhouse gas (GHG) emissions during global lockdowns. In addition, COVID-19 has affected social fabric, behaviors, cultures and official routines. Around 2.84 bn doses have been administrated, with approximately 806 m people (10.3% of the world population) are fully vaccinated around the world to date. Most developed vaccines are being evaluated for new variants like alpha, beta, gamma, epsilons and delta first detected in the UK, South Africa, Brazil, USA and India. The COVID-19 pandemic has affected all sectors in society, yet this paper critically reviews the impact of COVID-19 on health and energy lifelines.

This paper critically reviews the health and energy lifelines during pandemic COVID-19 and explains how these essential services were interrupted.

This paper critically reviews the health and energy lifelines during pandemic COVID-19 and explains how these essential services were interrupted.

The purpose of this paper is to present the results of a conceptual design of Martian aircraft. This study focuses on the aerodynamic and longitudinal dynamic stability analysis. The main research questions are as follows: Does a tailless aircraft configuration can be used for Martian aircraft? How to the short period characteristic can be improved by side plates modification?

Because of a conceptual design stage of this Martian aircraft, aerodynamic characterises were computed by the Panukl package by using the potential flow model. The longitudinal dynamic stability was computed by MATLAB code, and the derivatives computed by the SDSA software were used as the input data. Different aircraft configurations have been studied, including different wing’s aerofoils and configurations of the side plate.

This paper presents results of aerodynamic characteristics computations and longitudinal dynamic stability analysis. This paper shows that tailless aircraft configuration has potential to be used as Martian aircraft. Moreover, the study of the impact of side plates’ configurations on the longitudinal dynamic stability is presented. This investigation reveals that the most effective method to improve the short period damping ratio is to change the height of the bottom plate.

The presented result might be useful in case of further design of the aircrafts for the Mars mission and designing the aircrafts in a tailless configuration.

It is considered by the human expedition that Mars is the most probable planet to explore. This paper presents the conceptual study of aircraft which can be used to take the high-resolution pictures of the surface of Mars, which can be crucial to find the right place to establish a potential Martian base.

Most of aircrafts proposed for the Mars mission are designed in a configuration with a classic tail; this paper shows a preliminary calculation of the tailless Martian aircraft. Moreover, this paper shows the results of a dynamic stability analysis, where similar papers about aircrafts for the Mars mission do not show such outcomes, especially in the case of the tailless configuration. Moreover, this paper presents the results of the dynamic stability analysis of tailless aircraft with different configurations of the side plates.

This paper aims to investigate the possibility of lowering the time taken during the aircraft design for unmanned aerial vehicles by using machine learning (ML) for the configuration selection phase. In this work, a database of unmanned aircraft is compiled and is proposed that decision tree classifiers (DTC) can understand the relations between mission and operational requirements and the resulting aircraft configuration.

This paper presents a ML-based approach to configuration selection of unmanned aircraft. Multiple DTC are built to predict the overall configuration. The classifiers are trained with a database of 118 unmanned aircraft with 57 characteristics, 47 of which are inputs for the classification problem, and 10 are the desired outputs, such as wing configuration or engine type.

This paper shows that DTC can be used for the configuration selection of unmanned aircraft with reasonable accuracy, understanding the connections between the different mission requirements and the culminating configuration. The framework is also capable of dealing with incomplete databases, maximizing the available knowledge.

This paper increases the computational usage for the aircraft design while retaining requirements’ traceability and increasing decision awareness.