Investigation of the Contribution of Deceleration Fuel Cut-off and Start/Stop Technologies to Fuel Economy by Considering New European Driving Cycle

Greenhouse gas (GHG) emissions released into the atmosphere cause climate change and air pollution. One of the main causes of GHG emissions is the transportation sector. The use of fossil fuels in internal combustion engine vehicles leads to the release of these harmful gases. For this reason, since 1992, several standards have been introduced to limit emissions from vehicles. Technologies such as reducing engine sizes, advanced compression-ignition or start/stop, and fuel cut-off have been developed to reduce fuel consumption and emissions. In this study, the contribution of deceleration fuel cut-off and start/stop technologies to fuel economy has been examined considering the New European Driving Cycle. Therefore, the fuel consumption values were calculated by creating a longitudinal vehicle model for a light commercial vehicle with a diesel engine. At the end of the study, by using the two strategies together, fuel economies of 17.5% in the urban driving cycle, 3.7% in the extra-urban cycle, and 10% in total were achieved. CO2 emissions decreased in parallel with fuel consumption, by 10.1% in total.

EXPERIMENTAL ANALYSIS OF DOUBLE BOX WING UAV.

In an attempt to reduce the induced drag on a wing, Prandtl found that induced drag reduced significantly by highly increasing the number of vertically offset wings. The same result could be obtained by joining the wingtips of two vertically offset wings. This helped increase payload capacity and also reduced fuel consumption and emissions. Such a wing configuration came to be known as Prandtl’s box wing. In this work, the design and analysis of a box wing aircraft model has been carried out. The preliminary analysis is performed using XFLR5, and the computational analysis is done with the help of ANSYS 18.2. The values of experiments are computed with the help of MATLab R2017. The box wing model has shown a nearly 53.74% reduction in drag as compared with conventional wing models. The computational results of drag have been compared and validated with the results of analytical and the experimental results from the wind tunnel and found to be within 10% of the computational result. Since the drag of the box wing is significantly lesser than the conventional wings the box wing is a feasible configuration which can be used to design various aircrafts including Unmanned Aerial Vehicles and Commercial Planes.

A Study the Effect of Biodiesel Blends and the Injection Timing on Performance and Emissions of Common Rail Diesel Engines

This paper presents a study on the effect of the ratio of biodiesel and injection timing on the performance of diesel engines and their emissions. The research engine is a cylinder engine AVL-5402, simulated by software AVL-Boost. The simulated fuel includes fossil diesel and biodiesel blended with a replacement rate from 0% to 50%, with a simulation mode of 2200 (rev/min), at a rate of a 25%, 50% and 75% load. In this speed range, the engine has the lowest fuel consumption. The parameters to be evaluated are power, fuel consumption and emissions, based on the proportions of blended biodiesel. The results show that there is a relationship between the proportion of blended biodiesel, injection timing and the parameters of the engine. Specifically, the ratio of the biodiesel blend increases, injection timing tends to move closer to the top dead center (TDC), the tendency reduce engine power, fuel consumption increases, the emissions of CO and soot reduces, while NOx increases.

The Effect of Driving Cycle Duration on its Representativeness

There is an increasing interest in properly representing local driving patterns. The most frequent alternative to describe driving patterns is through a representative time series of speed, denominated driving cycle (DC). However, the DC duration is an important factor in achieving DC representativeness. Long DCs involve high testing costs, while short DCs tend to increase the uncertainty of the fuel consumption and tailpipe emissions results. There is not a defined methodology to establish the DC duration. This study aims to study the effect of different durations of the DCs on their representativeness. We used data of speed, time, fuel consumption, and emissions obtained by monitoring for two months the regular operation of a fleet of 15 buses running in two flat urban regions with different traffic conditions. Using the micro-trips method, we constructed DCs with a duration of 5, 10, 15, 20, 25, 30, 45, 60, and 120 min for each region. For each duration, we repeated the process 500 times in order to establish the trend and dispersion of the DC characteristic parameters. The results indicate that to obtain driving pattern representativeness, the DCs must last at least 25 min. This duration also guarantees the DC representativeness in terms of energy consumption and tailpipe emissions.

Determination of fuel consumption and pollutant emissions with the real-time engine running data of aircrafts in the taxi-out period

Purpose The purpose of this paper is to calculate the fuel consumption and emissions of carbon monoxide (CO), nitrogen oxide (NOx) and hydrocarbons (HC) in the taxi-out period of aircraft at the International Diyarbakir Airport in 2018 and 2019. Design/methodology/approach Calculations were performed by determining the engine operating times in the taxi-out period with the flight data obtained from the airport authority. In the analyses, aircraft series and aircraft engine types were determined, and the Engine Exhaust Emission Databank of the International Civil Aviation Authority (ICAO) were used for the calculation. Findings Total fuel consumption in the taxi-out period in 2018 and 2019 was calculated as 525.64 and 463.69 tons, respectively. In 2018, HC, CO and NOx emissions caused by fuel consumption were found to be 1,109, 10,668 and 2,339 kg, respectively. In 2019, the total HC, CO and NOx emissions released to the atmosphere during the taxi-out phase are 966, 9,391 and 2,126 kg, respectively. B737 Series aircraft have the largest share in total fuel consumption and pollutant emissions. Practical implications This study explains the importance of determining fuel consumption and pollutant emissions by considering engine operating times in the taxi-out period. The study provides aviation authorities with scientific methods to follow in calculating fuel consumption and emissions from aircraft operations. Originality/value The originality of this study is the calculation of fuel consumption and pollutant emissions by determining real-time engine running times in the taxi-out period. In addition, calculations were made with real engine operating times determined in the taxi-out period using real flight data.

Influence of Environmental Changes Due to Altitude on Performance, Fuel Consumption and Emissions of a Naturally Aspirated Diesel Engine

The present study shows the effects of environmental conditions (atmospheric temperature, pressure and relative humidity) due to altitude changes on performance, fuel consumption and emissions in a naturally aspirated diesel engine. Due to changes in altitude, the atmospheric conditions are altered, mainly the air density, associated to hydrostatic pressure, temperature profile and humidity and relative nitrogen/oxygen ratio, thus modifying the engine intake conditions. The study considers changes in altitude from sea level to 2500 m above sea level, which are representative of the orographic conditions in Ecuador. As a main part of this research, a parametric study of variation of atmospheric temperature, pressure and relative humidity is carried out in AVL BOOST™, showing the effects on mean effective pressure, fuel consumption and specific pollutant emissions (CO2, NOx, CO and soot). The study considers effects at regional level (change from an altitude to another) and local level (changes in the atmospheric conditions due to local anticyclone or storm, temperature and humidity). The quantitative effects are expressed in the form of sensitivity coefficients, e.g., relative change in an engine output variable due to the change in atmospheric pressure, temperature or humidity. In addition, several global correlations have been obtained to provide analytical expressions to summarize all results obtained, showing the separate effect of pressure and temperature on each engine performance variable.

Relation between Energy Efficiency and GHG Emissions in Drying Units Using Forest Biomass

The impacts of climate change are inevitable and driven by increased levels of greenhouse gases (GHG) in the atmosphere, requiring mitigation and re-adaptation measures. In this context, this article critically analyzes the influence of drying technology type, forest biomass, and GHG emissions resulting from the energy required for drying agricultural crops, by presenting a case study of tobacco drying. In this study, the influence of increasing the technological level of drying unit (curing units CUs), using E. saligna and E. dunnii firewood and Pinus sp. pellets, was evaluated; considering consumption efficiency, energy efficiency, and concentration of gas emissions (CO, CO2, CXHY and NOX), as well as emission factors in tCO₂-eq. The results showed that when increasing the technological level of the CUs, there is a decrease in fuel consumption and emissions. The reduction can reach 60.28% for the amount of biomass consumed and 67.06% in emissions in tCO₂-eq; for the scenario of a production crop, using a CU with a continuous load (Chongololo) and firewood from E. dunnii. The use of pellets proved to be efficient, with the lowest consumption of biomass and emissions with more technological CUs.

PECULIARITIES OF DETERMINATION OF FUEL CONSUMPTION AND EMISSIONS OF HARMFUL SUBSTANCES OF ENGINES OF VEHICLES OPERATING ON GAS FUEL

The article considers the features of the method of research of fuel economy and environmental performance of vehicles with engines converted to run on gas fuel, which are equipped with a thermal training system based on a thermal accumulator phase transition, which is based on the implementation of system interaction of three interconnected components: information, analytical and energy. The schematic diagram of the system of thermal preparation and the information system of estimation of ways of maintenance of thermal preparation of vehicles in the conditions of operation by means of system of thermal preparation on the basis of an onboard complex (Intelligent transportation system) are presented. The peculiarity of the proposed system is that the subsystems create a common information field of the vehicle monitoring system with the heat treatment system, but operate separately from each other, based on the characteristics of the tasks they perform. Improved is the method for determining and calculating fuel consumption and emissions in exhaust gases of vehicles with engines converted to run on gas fuel, equipped with a thermal accumulator phase transition in the processes of pre-start and post-start heat treatment based on the selected model of the engine "Neutralizer". To ensure thermal preparation of vehicles with engines converted to run on gas fuel, equipped with a thermal training system based on a thermal accumulator of the phase transition, a cycle of thermal preparation in operating conditions has been developed. The influence of the thermal preparation system with the heat accumulator of the phase transition of a vehicle with an engine converted to run on gas fuel on the fuel efficiency indicators and environmental indicators in the pre-start and post-start-up processes is established.