A comprehensive model is developed to estimate and predict the fuel consumption and emissions by domestic commercial aviation in the Continental United States. Most of the existing fuel consumption and emission models are limited in their ability to predict the annual fuel burn for air transportation at the national level. For example, those models either require real track data or are developed only to model single flight scenarios.  The model developed in this thesis is part of a software framework called the Transportation Systems Analysis Model (TSAM). The model has the capability to estimate fuel consumption and emissions for millions of domestic flights in a year in the continental U.S. TSAM is a nationwide, long-distance, multimodal travel demand forecast model developed at Virginia Tech. The model enables TSAM to quantify fuel and emission metrics for various modes of transportation. The EUROCONTROL Base of Aircraft Data (BADA) is employed as the Aircraft Performance Model to simulate individual flight profiles and calculate fuel burn rates. Fuel consumption on the ground (taxi mode) is estimated separately. Different operational conditions like wind states, terminal area detour, cruise altitude and airport elevation are considered in the model. Emissions of HC, CO, NOx and SOx are computed inside the Landing/Take-off (LTO) cycle based on the fuel consumption estimate, while greenhouse gas of CO2 is calculated for the complete flight cycle. / Master of Science

EPA testing methods for calculation of fuel economy label ratings, which were revised beginning in 2008, use equations that weight the contributions of fuel consumption results from multiple dynamometer tests to synthesize city and highway estimates that reflect average U.S. driving patterns. The equations incorporate effects with varying weightings into the final fuel consumption, which are explained in this thesis paper, including illustrations from testing. Some of the test results used in the computation come from individual phases within the certification driving cycles. This methodology causes additional complexities for hybrid electric vehicles, because although they are required to have charge-balanced batteries over the course of a full drive cycle, they may have net charge or discharge within the individual phases. The fundamentals of studying battery charge-balance are discussed in this paper, followed by a detailed investigation of the implications of per-phase charge correction that was undertaken through testing of a 2010 Toyota Prius at Argonne National Laboratory's vehicle dynamometer test facility. Using the charge-correction curves obtained through testing shows that phase fuel economy can be significantly skewed by natural charge imbalance, although the end effect on the fuel economy label is not as large. Finally, the characteristics of the current 5-cycle fuel economy testing method are compared to previous methods through a vehicle simulation study which shows that the magnitude of impact from mass and aerodynamic parameters vary between labeling methods and vehicle types. / Master of Science

With the progress and expansion of civilization, companies are interested in distributing their products and goods in distributed areas on a daily basis. These daily tasks are considered to ensure that the products reach the largest possible number of people to keep pace with accommodating the expansion and population. However, these daily duties demand a lot of effort and are financially burdened on both drivers and companies as well. Besides that, daily transportation might cause traffic congestion as well as being negative on the environment with harmful emissions coming from heavy-duty trucks. With overcrowding, companies may face delays in the arrival of their products to their customers, which is a point that may reflect negatively on the company's reputation in the business. One of the proposed solutions for companies to deal with these problems is to create a platoon of trucks during their transportation between the pickup stations and the drop-off stations. The literature review demonstrates that there are written benefits for the truck platoons, however, there is a lack of showing these benefits in the reality. The platoon simulation was built in this thesis to present the results numerically so that they could be contrasted with scenarios where the platoon was not used for freight transportation. This thesis focused on the benefits of a platoon from three aspects: the aspect of saving time, reducing cost by reducing fuel usage, and finally increasing safety in public driving on highways. The results of using the simulations showed that the time was using to deliver the goods by using truck platoons was shorter than the time by using individual trucks. Additionally, traffic congestion was less when the trucks were driven on single-lane on highways, which causes reduced the number of accidents especially, those that occurred with small cars. They compiled accident data between 2007 and 2017, coming to the conclusion that 98,790 crashes involving large trucks were among the 243,017 total crashes. In the same survey, the authors found that 9.4% of truck accidents occurred when changing lanes with small cars on highways. This thesis demonstrated numerically that there was less fuel usage while the trucks were driven in a platoon compared with the fuel usage of the trucks that were driven individually. In a word, transportation companies will gain benefits from using truck platoons to deliver their goods to their customers.

Thesis (MScIngwet)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: The diesel consumption of haul trucks deployed on opencast mines was investigated as a means of reducing the Total Cost of Ownership (TCO) of mining haul trucks. The conceptualisation of TCO and an introduction to the mining operation was presented as an introduction to the field of research. Thereafter, a review of the available literature revealed that linear programming, queueing theory and coast-down testing were applicable means of investigation. The relevant engineering sciences were applied and correlated with experimental and measured data from the Grootegeluk, Sishen and Thabazimbi mines operated by Kumba Resources Ltd (formerly known as ISCOR Mining). A cost-driver model for diesel consumption was formulated by exploiting the expert judgement of role players in the mining operation. A cost-driver model was developed for the Sishen, Thabazimbi and Grootegeluk mines. The cost-driver models were then modelled as a linear programming problem and solved using the student version of LINDO Optimization Software. The results were discussed and a universal diesel cost driver model was formulated by consolidating the individual diesel cost driver models. The operational cycle of haul trucks was simulated in order to quantify equipment utilisation and reduce diesel consumption of the mining vehicles. The operational cycle of haul trucks was modelled utilising queueing theory. The simulation of the queue network was implemented in Matlab using the next event advance method and was called Q Sim. Q Sim - - was utilised to investigate optimal fleet size and the economies of scale of haul truck capacity. The results of coast down tests were analysed in order to determine the effect of treating mining roads, with a bitumen product, on rolling resistance coefficient. Finally, recommendations for further research are proposed. This includes further refinement of the diesel cost-driver model, expanding the scope of application of Q_Sim in the mining operation and further investigation of dust reduction by bitumen products. / AFRIKAANSE OPSOMMING: Ondersoek is ingestel na die dieselverbruik van myntrokke sodoende die Totale Koste van Eienaarskap (TKE) van myntrokke te verminder. Die konsep rondom TKE is bespreek en 'n inleiding tot die mynybedryf is aangebied sodoende die verskeie aspekte in verb and te bring. 'n Literatuur studie het gevolg, wat aangetoon het dat lineere programmeering, toustaan-en loswieltoetse toepaslike navorsingsmetodes is om die nodige resultate te verkry. Daarna is hierdie ingenieurswetenskappe toegepas en 'n vergelyking is tussen die eksperimentele en gemete data van die Grootegeluk, Sishen en Thabazimbi myne getref. 'n Diesel koste-drywer model is opgestel met die insette van kundige rolspelers in die mynbou bedryf. Dit het gelei tot Koste-drywer modelle vir die Sishen, Thabazimbi en Grootegeluk myne. Die modelle is met lineere programmeering as probleemstelling daargestel en is deur middel van die studente weergawe van die LINDO optimaliseringssagteware opgelos. Die resultate was toe bespreek en daarvolgens is 'n universele diesel koste-drywer model opgestel deur die reeds-geskepte modelle te konsolideer. Die operasionele siklus van myntrokke was gesimuleer sodoende die benutting van toerusting te kwantifiseer en die dieselverbruik van myntrokke te verminder. Hierdie operasionele siklus was gemodelleer deur middel van die toustaan-teorie. Die simulasie van 'n toustaannetwerk was in Matlab gevoer deur Q_Sim te gebruik. Hierdie metode was gebruik om die optimale vloot grootte en die invloed van myntrokkapasiteit te ondersoek. Die ontleding van die loswieltoetse was gedoen om die invloed van In bitumen prod uk op rolweerstand te bepaal. Ten slotte is aanbevelings vir toekomstige navorsing bespreek. Dit behels die verder aansuiwerings van die diesel koste-drywer model, die uitbreiding van aanwending van die Q_Sim in die mynbou en 'n verdere ondersoek om stofvoorkoming in die mynbou te bewerkstellig deur die gebruikmaking van bitumen produkte.

The air hybrid engine absorbs the vehicle kinetic energy during braking, stores it in an air tank in the form of compressed air, and reuses it to start the engine and to propel a vehicle during cruising and acceleration. Capturing, storing and reusing this braking energy to achieve stop-start operation and to give additional power can therefore improve fuel economy, particularly in cities and urban areas where the traffic conditions involve many stops and starts. In order to reuse the residual kinetic energy, the vehicle operation consists of 3 basic modes, i.e. Compression Mode (CM), Expander Mode (EM) and normal firing mode, as well as stop-start operation through an air starter. A four-cylinder 2 litre diesel engine has been modelled to operate in four air hybrid engine configurations so that the braking and motoring performance of each configuration could be studied. These air hybrid systems can be constructed with production technologies and incur minimum changes to the existing engine design. The regenerative engine braking and starting capability is realised through the employment of an innovative simple one-way intake system and a production cam profile switching (CPS) mechanism. The hybrid systems will allow the engine to be cranked by the compressed air at moderate pressure without using addition starters or dedicated valves in the cylinder head. Therefore, the proposed air hybrid engine systems can be considered as a cost-effective regenerative hybrid powertrain and can be implemented in vehicles using existing production technologies. A novel cost-effective pneumatic regenerative stop-start hybrid system, Regenerative Engine Braking Device (RegenEBD), for buses and commercial vehicles is presented. RegenEBD is capable of converting kinetic energy into pneumatic energy in the compressed air saved in an air tank using a production engine braking device and other production type automotive components and a proprietary intake system design. The compressed air is then used to drive an air starter to achieve regenerative stop-start operations. The proposed hybrid system can work with the existing vehicle transmission system and can be implemented with the retro-fitted valve actuation device and a sandwich block mounted between the cylinder head and the production intake manifold. Compression mode operation is achieved by keeping the intake valves from fully closed throughout the four-strokes through a production type variable valve exhaust brake (VVEB) device on the intake valves. As a result, the induced air could be compressed through the opening gap of intake valves into the air tank through the intake system of proprietary design. The compressed air can then be used to crank the engine directly through the air expander operation or indirectly through the action of an air starter in production. A single cylinder camless engine has been set up and operated to evaluate the compression mode performance of two air hybrid concepts. The experimental results are then compared with the computational output with excellent agreement. In order to evaluate the potential of the air hybrid engine technologies, a new vehicle driving cycle simulation program has been developed using Matlab Simulink. An air hybrid engine sub-model and methodology for modelling the air hybrid engine’s performance have been proposed and implemented in the vehicle driving cycle simulation. The NEDC analysis of a Ford Mondeo vehicle shows that the vehicle can achieve regenerative stop-start operations throughout the driving cycle when it is powered by a 2.0litre diesel engine with air hybrid operation using a 40litre air tank of less than 10bar pressure. The regenerative stop-start operation can lead to 4.5% fuel saving during the NEDC. Finally, the Millbrook London Transport Bus (MLTB) driving cycle has been used to analyse the effectiveness of RegenEBD on a double deck bus powered by a Yuchai diesel engine. The results show that 90% stop-starts during the MLTB can be accomplished by RegenEBD and that a significant fuel saving of 6.5% can be obtained from the regenerative stop-start operations.

Nowadays the needs to fulfill severe emission standards and to reduce the mobile machine operative costs have driven the off-highway industrial research towards new solutions able to increase the overall vehicle efficiency. Within this scenario, smart power split transmissions demonstrated to be a very attractive technology able to achieve the fuel consumption reduction targets, increasing the machine working cycle productivity. Compared to the standard technologies (such as Torque Converters - TC), the power split hydromechanical varible transmissin (HVT), designed and developed by Dana Rexroth Transmission Systems S.r.l. (DRTS), is able to fully decouple the engine to wheel behavior during the machine working cycle, with an higher efficiency than a pure hydrostatic transmission. Due to this fundamental characteristic, the HVT allows the engine to work next to the maximum efficiency point, consequently it is possible to downsize the engine to further increase the fuel saving. The analysis of the field test performed by an off-highway vehicle (Kalmar Cargotec DRG Gloria 450 reachstacker) equipped with a DRTS HVT has been shown along this paper; particular attention has been given to the cycle load spectra, the fuel consumption and the working cycle productivity through a comparison with standard TC technologies.

O presente trabalho apresenta uma proposta de desenvolvimento e aplicação de um programa de simulação computacional usando o software MatLab/Simulink 6.0 como ferramenta de Engenharia Automotiva, aplicando-a para o estudo do desempenho de veículos comerciais rodoviários (caminhonetes, caminhões e ônibus) em movimentos acelerados e em regime permanente. O programa de simulação considera o motor mapeado em torque e consumo específico e o sistema de transmissão do eixo do motor às rodas motrizes e se conecta a outro programa de simulação existente e desenvolvido no Laboratório de Computação Veicular da EESC-USP. Para as simulações foram utilizados os dados de um veículo comercial característico submetido a várias situações de movimento acelerado em pista horizontal e inclinada, quando foram obtidos dados importantes como consumo médio e instantâneo do veículo para cada um dos cenários previstos. Outros dados como os espaços percorridos, as velocidades, as acelerações, as rotações do eixo do motor, o escorregamento parcial dos pneumáticos e outros são apresentados neste trabalho. Adicionalmente, o programa de simulação mostra potencial de uso nas fases de projeto, desenvolvimento e otimização dos veículos comerciais, podendo reduzir custos com a diminuição dos prazos e testes necessários para a avaliação do desempenho do veículo em pista de provas. Apresenta também potencial de aplicação na melhor especificação do veículo a ser comprado pelo frotista considerando as condições específicas do seu uso. / This work presents a development and application proposal of a simulation program using the software Matlab/Simulink 6.0 as an Automotive Enginnering tool, applying it for the study of the commercial vehicles performance in accelerated and uniform movement. The simulation program considers the engine maps of specific fuel consumption and torque curves and also the transmission system between the engine and the tractive wheels. The simulation program connects itself with another simulation program developed in the EESC-USP Vehicle Computation Laboratory. For the simulations were used the data of a characteristic commercial vehicle submited to various situations on horizontal and inclinated roads, when were taken relevant data like average and instant fuel consumption for each predicted scene. This work also presents vehicle operational data as engine speed, covered spaces, longitudinal velocities and accelerations, adherence and relative slip of the wheels and others. The simulation program shows a hugh potential use in the optimization, development and project phases of commercial vehicles, allowing saving of time and financial resources. The simulation program shows also a potential application in the best vehicle specification to be bought by the client considering the specific conditions of its use.

Engine thermal and lubricant systems have only recently been a serious focus in engine design and in general remain under passive control. The introduction of active control has shown benefits in fuel consumption during the engine warm-up period, however there is a lack of rigorous calibration of these devices in conjunction with other engine systems. For these systems, benefits in fuel consumption (FC) are small and accurate measurement systems are required. Analysis of both FC and NOx emissions measurements processes was conducted and showed typical errors of 1% in FC from thermal expansion and 2% in NOx per g/kg change in absolute humidity. Correction factors were derived both empirically and from first principles to account for these disturbances. These improvements are applicable to the majority of experimental facilities and will be essential as future engine developments are expected to be achieved through small incremental steps. Using prototype hardware installed on a production 2.4L Diesel engine, methodologies for optimising the design, control and integration of these systems were demonstrated. Design of experiments (DoE) based approaches were used to model the engine behaviour under transient conditions. A subsequent optimisation procedure demonstrated a 3.2% reduction in FC during warm-up from 25°C under iso-NOx conditions. This complemented a 4% reduction from reduced oil pumping work using a variable displacement pump. A combination of classical DoE and transient testing allowed the dynamic behaviour of the engine to be captured empirically when prototype hardware is available. Furthermore, the enhancement of dynamic DoE approaches to include the thermal condition of the engine can produce models that, when combined with other available simulation packages, offer a tool for design optimisation when hardware is not available. These modelling approaches are applicable to a wide number of problems to evaluate design considerations at different stages of the engine development process. These allow the transient thermal behaviour of the engine to be captured, significantly enhancing conventional model based calibration approaches.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1979. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND AERONAUTICS. / Bibliography: leaf 72. / by Yuji Hanawa. / M.S.

Driven by the strict fuel consumption and CO2 legislations in Europe and many countries, various technologies have been developed to improve the fuel economy of conventional internal combustion engines. Gasoline engine downsizing has become a popular and effective approach to reduce fleet CO2 emissions of passenger cars. This is typically achieved in the form of boosted direct injection gasoline engines equipped with variable valve timing devices. Downsized gasoline engines reduce vehicle fuel consumption by making engine operate more at higher load to reduce pumping losses and also through reducing total engine friction losses. However, their compression ratio (CR) and efficiency are constrained by knocking combustion as well as the low speed pre-ignition phenomena. Miller cycle is typically achieved in an engine with reduced effective CR through Early Intake Valve Closure (EIVC) or Later Intake Valve Closure (LIVC). This technology has been adopted on modern gasoline engines to reduce in-cylinder charge temperature and enable a higher geometric CR to be used for better fuel economy. The present work investigated the effectiveness and underlying process of a Miller cycle based approach for improving fuel consumption of a boosted downsized gasoline engine. A single cylinder direct injection gasoline engine and the testing facilities were set up and used for extensive engine experiments. Both EIVC and LIVC approaches were tested and compared to the conventional Otto cycle operation with a standard cam profile. Synergy between Miller cycle valve timings and different valve overlap period was analysed. Two pistons with different CRs were used in the Miller cycle engine testing to enable its full potential to be evaluated. The experimental study was carried out in a large engine operation area from idle to up to 4000rpm and 25.6bar NIMEP to determine the optimal Miller cycle strategy for improved engine fuel economy in real applications. In addition, the increased exhaust back pressure and friction losses corresponding to real world boosting devices were calculated to evaluate Miller cycle benefits at high loads in a production engine. The results have shown that EIVC combined with high CR can offer up to 11% reduction of fuel consumption in a downsized gasoline engine with simple setup and control strategy. At the end, this thesis presents an Miller cycle based approach for maximising fuel conversion efficiency of a gasoline engine by combining three-stage cam profiles switching and two-stage variable compression ratio.