BATTERY ELECTRIC AIRCRAFT FEASIBILITY INVESTIGATION INCLUDING A BATTERY-IN-WING CONCEPTUAL DESIGN

The feasibility of converting an existing internal combustion powered general aviation aircraft to battery electric propulsion was studied. The theoretical performance of various types of airframes with battery electric propulsion systems was compared to determine which type of airframe would be best suited for conversion. It was found that battery electric propulsion is best used in aircraft intended for slow speed, efficient flight and carrying limited payload which is a mission typically flown in motor gliders. A reference motor glider was selected and a conceptual power system packaging design study was performed. The study determined that a critical component of the power system packaging design was the technical feasibility of packaging the batteries inside of the wing structure. This was driven by center of gravity restrictions. Technical concerns related to a battery-in-wing design were investigated, included wing aeroelastic performance, wing stiffness and wing strength. The results showed that aeroelastic flutter was not a driving design criteria for the reference airframe used as the physical size of the battery did not allow for them to be packaged in wing locations that detrimentally affected flutter performance. The battery packaging layout was instead driven by access for battery maintenance, battery safety and the battery thermal management system. Overall weight change from packaging the batteries in the wing compared to the fuselage was found to be negligible. The resulting aircraft conceptual design indicated a powered flight range with reserves of over 200 miles and a powered flight endurance of greater than 3 hours with 2 persons onboard

Cooling and Heat Exchangers for Hydrogen Fuel Cell System

V této diplomové práci je představen návrh chladicího systému a tepelného výměníku pro odul palivových buňek. Cílem diplomové práce je navrhnout tepelný výměník spolu s dalšími součástmi chladicího systému, jaké jsou ventilátor a čerpadlo, tak aby byly v souladu s počátečními podmínkami. Obsahem této práce jsou též typy palivových buněk, modul palivových buněk, jeho nezbytné součásti a řešení pro chlazení modulu palivových buněk. Na základě stanovených podmínek byly navrženy dva tepelné výměníky s různými designy, byla vysvětlena jejich teorie a metodologie, těž byly vybrány ventilátor a čerpadlo pro oba designy.In this master’s thesis study, cooling system and heat exchanger design for of a fuel cell module is presented. The aim of the prepared thesis is to design heat exchanger along with other cooling system components, being fan and pump, in accordance with initial conditions. Content of this study consists also of fuel cell types, fuel cell module, its necessary components and solution for cooling of the fuel cell module. According to the given conditions, two heat exchangers with different layouts have been designed and theory and methodology behind it has been discussed, as well as fan and pump for both designs has been selected

Electronic/electric technology benefits study

The benefits and payoffs of advanced electronic/electric technologies were investigated for three types of aircraft. The technologies, evaluated in each of the three airplanes, included advanced flight controls, advanced secondary power, advanced avionic complements, new cockpit displays, and advanced air traffic control techniques. For the advanced flight controls, the near term considered relaxed static stability (RSS) with mechanical backup. The far term considered an advanced fly by wire system for a longitudinally unstable airplane. In the case of the secondary power systems, trades were made in two steps: in the near term, engine bleed was eliminated; in the far term bleed air, air plus hydraulics were eliminated. Using three commercial aircraft, in the 150, 350, and 700 passenger range, the technology value and pay-offs were quantified, with emphasis on the fiscal benefits. Weight reductions deriving from fuel saving and other system improvements were identified and the weight savings were cycled for their impact on TOGW (takeoff gross weight) and upon the performance of the airframes/engines. Maintenance, reliability, and logistic support were the other criteria

Urban and extra-urban hybrid vehicles: a technological review

Pollution derived from transportation systems is a worldwide, timelier issue than ever. The abatement actions of harmful substances in the air are on the agenda and they are necessary today to safeguard our welfare and that of the planet. Environmental pollution in large cities is approximately 20% due to the transportation system. In addition, private traffic contributes greatly to city pollution. Further, “vehicle operating life” is most often exceeded and vehicle emissions do not comply with European antipollution standards. It becomes mandatory to find a solution that respects the environment and, realize an appropriate transportation service to the customers. New technologies related to hybrid –electric engines are making great strides in reducing emissions, and the funds allocated by public authorities should be addressed. In addition, the use (implementation) of new technologies is also convenient from an economic point of view. In fact, by implementing the use of hybrid vehicles, fuel consumption can be reduced. The different hybrid configurations presented refer to such a series architecture, developed by the researchers and Research and Development groups. Regarding energy flows, different strategy logic or vehicle management units have been illustrated. Various configurations and vehicles were studied by simulating different driving cycles, both European approval and homologation and customer ones (typically municipal and university). The simulations have provided guidance on the optimal proposed configuration and information on the component to be used

Apollo experience report: Development of the extravehicular mobility unit

The development and performance history of the Apollo extravehicular mobility unit and its major subsystems is described. The three major subsystems, the pressure garment assembly, the portable life-support system, and the oxygen purge system, are defined and described in detail as is the evolutionary process that culminated in each major subsystem component. Descriptions of ground-support equipment and the qualification testing process for component hardware are also presented

Maintenance program for Electric Vehicles power train by Reliability Centred Maintenance

The reduction of environmental pollution is one of the greatest challenges for humanity, today and for the immediate future. Air quality is one of the most critical aspects in determining people’s health, particularly in big cities, and transportation emissions are currently considered accountable for almost 32% of total air contamination. The more widespread use of green vehicles could have important effects both on the environment and the economy, and this thesis work intends to focus on reliability and maintainability of pure-electric vehicles (EVs). The main objectives of this paper are: • To conduct research into state-of -art of pure-electric car powertrain technology, describing the functions and operations of its various components: mechanical, electrical and the control links between those components are all carefully considered. • To identify and define a long term maintenance plan for the power train system, utilising the RCM method. In order to achieve these targets and objectives, a wide literature review will be conducted on existing electric vehicle technology, taking already published and available information from similar technologies which are more mature than EVs one, but with comparable run conditions and operations. The method adopted for this maintenance study is Reliability Centred Maintenance (RCM): this logic will be reviewed and applied to the powertrain system, designing and completing proper worksheets (COFA worksheet and PM task worksheet) which will form the suggested maintenance plan. This proposed plan consists of various elements including: failure modes identification, failure effects on the vehicle, criticality classification of the components, failure causes identification and suggested preventive maintenance tasks with proper periodicity. In the final part of the paper, the results and outcomes of the analysis will be discussed, and possible future developments will be identified

Feasibility of Electrified Propulsion for Ultra-Efficient Commercial Aircraft Final Report

MIT, Aurora Flight Sciences, and USC have collaborated to assess the feasibility of electric, hybridelectric, and turbo-electric propulsion for ultra-efficient commercial transportation. The work has drawn on the team expertise in disciplines related to aircraft design, propulsion-airframe integration, electric machines and systems, engineering system design, and optimization. A parametric trade space analysis has been carried out to assess vehicle performance across a range of transport missions and propulsion architectures to establish how electrified propulsion systems scale. An optimization approach to vehicle conceptual design modeling was taken to enable rapid multidisciplinary design space exploration and sensitivity analysis. The results of the analysis indicate vehicle aero-propulsive integration benefits enabled by electrification are required to offset the increased weight and loss associated with the electric system and achieve enhanced performance; the report describes the conceptual configurations than can offer such enhancements. The main contribution of the present work is the definition of electric vehicle design attributes for potential efficiency improvements at different scales. Based on these results, key areas for future research are identified, and extensions to the trade space analysis suitable for higher fidelity electrified commercial aircraft design and analysis have been developed

MOTOR DRIVE & E�ERGY MA�AGEME�T FOR ELECTRIC VEHICLE USI�G �ATIO�AL I�STRUME�TS COMPACT-RIO

Internal combustion engine vehicle (ICEVs) has been around for more than a century. However, the efficiency of ICEV is considered low, only 30% of the energy formed in the ICE combustion reaction is changed into mechanical power and the majority which is 70% of the energy is vanished into the form of exhaust gases heat. The exhaust gases are consists of mostly of carbon dioxide (CO2) and a smaller amount of nitrogen oxides (NOX), hydrocarbons (CXHY), carbon monoxide (CO) and others. Decreasing the dependency on fossil fuels burned in an ICE will directly impact environmental effects and increase the healthiness of human. Nowadays, pure Electric Vehicle (EV) and hybrid EV are obtainable by world’s greatest carmakers because they are significant potential for use in urban areas. Their power consumption ranges from approximately 10% to 70% lower than that of a comparable ICE car, depending on their power, size of battery, control approach, etc. In city traffic, because of their positive effect on environment, electric vehicle are a key factor for improvement of traffic and more particularly for an improved living environment. A very efficient energy-management system for electric vehicle will be developed and tested. The system minimizes the power requirement of the vehicle and extends the driving range of an electric vehicle. The intention of this project is to develop the energy management system within the electric vehicle to be able to monitor vehicle performance. The energy management system monitors the battery current, battery voltage, temperature, vehicle performance, power consumption, state of charge (SOC) of the battery, and gives feedback in terms of actions that need to do by driver. It will be implemented using National Instruments Compact-RIO hardware and programmed in LabVIEW, graphical application development environment

The Design Space Exploration and Preliminary Testing of a New Class of Tailsitting Quadrotor Aircraft

Within the last decade, multi-rotor aircraft have become the most prevalent form of unmanned aerial vehicle (UAV), with applications in the military, commercial, and civilian sectors. This is due primarily to advances in electronics that allow small-scale aircraft systems to be produced and controlled in an affordable manner. Such systems are maneuvered by precisely varying the thrust and torque of individual rotors to produce flight control forces, thereby eliminating much of the mechanical complexity inherent in conventional helicopter configurations. Although many UAV missions exploit the ability to hover in place, many also require the ability to quickly and efficiently dash from point to point. Rotorcraft, in general, are limited in this capacity, since rotor thrust must also be used to produce lift. Transitional aircraft represent an alternative that blends the vertical take-off and landing (VTOL) capabilities of rotorcraft with the forward flight performance of fixed-wing aircraft, but they often rely on cumbersome mechanisms, such as additional or rotating powerplants. UAVs, however, have no need to maintain cockpit orientation. Consequently, a tailsitting quadcopter concept was devised by Dr. Ron Barrett to combine quadcopter hovering performance with the high-speed flight of fixed-wing craft. This paper lays out the arguments for such an aircraft — the XQ-139 — and examines the performance of XQ-139 variants with installed power values ranging from 100 W to 10,000 kW. Battery-electric, rotary engine, turboprop, and hybrid propulsive options are considered, and the merits of each discussed. Additionally, an XQ-139 prototype was designed and constructed, and stationary test was used to compare the aircraft’s installed efficiency with that of a typical quadcopter. The prototype was found to be approximately 5% more efficient in hover mode than the quadcopter to which it was compared

Thermoelectric cookstove

A fuel efficient cookstove tailored to the needs of Nicaraguan small business owners that incorporated insulation and thermoelectric power generation was built and validated. There is a 4 inch layer of pumice rock insulation around the combustion chamber, which significantly reduces convective heat losses to the environment. The stove\u27s ventilation system is powered by the electricity generated by thermoelectric generators. Preheated air is forced into the combustion chamber, which increases the combustion efficiency, reducing the fuel consumption and the harmful smoke produced. Through various testing methods, we found that the controlled airflow to the charcoal fuel allows the stove to maintain the desired cooking temperature 38% longer that the standard inefficient stoves. This longer burn time translates directly into fuel savings, as the operator requires less fuel to accomplish the same cooking task. It is estimated that a customer could save at least $200/year on fuel, which represents two month\u27s salary in Nicaragua. Compared to uninsulated stoves, our design reduces the outer wall temperature by 700° F, which is a significant safety improvement. The voltage generated by the TEGs, typically between 1.5-2.5 volts, is enough to power the fans; however, more work needs to be done to optimize a power management circuit that would facilitate device charging