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Article
Publication date: 2 May 2017

Ali Dinc

This paper aims to present a genuine code developed for multi-objective optimization of selected parameters of a turboprop unmanned air vehicle (UAV) for minimum landing-takeoff…

Abstract

Purpose

This paper aims to present a genuine code developed for multi-objective optimization of selected parameters of a turboprop unmanned air vehicle (UAV) for minimum landing-takeoff (LTO) nitrogen oxide (NOx) emissions and minimum equivalent power specific fuel consumption (ESFC) at loiter (aerial reconnaissance phase of flight) by using a genetic algorithm.

Design/methodology/approach

The genuine code developed in this study first makes computations on preliminary sizing of a UAV and its turboprop engine by analytical method for a given mission profile. Then, to minimize NOx emissions or ESFC or both of them, single and multi-objective optimization was done for the selected engine design parameters.

Findings

In single objective optimization, NOx emissions were reduced by 49 per cent from baseline in given boundaries or constraints of compressor pressure ratio and compressor polytropic efficiency in the first case. In second case, ESFC was improved by 25 per cent from baseline. In multi-objective optimization case, where previous two objectives were considered together, NOx emissions and ESFC decreased by 26.6 and 9.5 per cent from baseline, respectively.

Practical implications

Variation and trend in the NOx emission index and ESFC were investigated with respect to two engine design parameters, namely, compressor pressure ratio and compressor polytropic efficiency. Engine designers may take into account the findings of this study to reach a viable solution for the bargain between NOx emission and ESFC.

Originality/value

UAVs have different flight mission profiles or characteristics compared to manned aircraft. Therefore, they are designed in a different philosophy. As a number of UAV flights increase in time, fuel burn and LTO NOx emissions worth investigating due to operating costs and environmental reasons. The study includes both sizing and multi-objective optimization of an UAV and its turboprop engine in coupled form; compared to manned aircraft.

Details

Aircraft Engineering and Aerospace Technology, vol. 89 no. 3
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 20 September 2021

Halil Yalcin Akdeniz

The purpose of this study is to estimate the nitrogen oxide (NOx), carbon monoxide (CO) and hydrocarbon (HC) emissions and their environmental and economic aspects during the…

Abstract

Purpose

The purpose of this study is to estimate the nitrogen oxide (NOx), carbon monoxide (CO) and hydrocarbon (HC) emissions and their environmental and economic aspects during the actual landing and take-off operations (LTO) of domestic and international flights at a small-scale airport. In this regard, the aircraft-induced NOx, CO and HC emissions analyses, the global warming potential (GWP) estimations of exhaust emissions and the life cycle assessment (LCA)-based environmental impact (EI) estimations of exhaust emissions, and the eco-cost estimation of exhaust emissions are measured.

Design/methodology/approach

Estimations and calculations are performed in parallel with the International Civil Aviation Organisation’s Engine Emission Databank and Intergovernmental Panel on Climate Change approaches. Also, to assess the environmental effect of the pollutants, the GWP and the EI analyses which is based on the LCA approaches are used. Finally, the eco-cost approach has been used to discuss the economic aspects of these emissions.

Findings

The total emissions of air pollutants from aircraft are estimated as 601.067 kg/y for HC, 6,074.905 kg/y for CO and 4,156.391 kg/y for NOx at the airport. Also, emissions from international flights account for 79% of emissions from all flights. The Airbus A321 type of aircraft has accounted for more than half of the total HC, CO and NOx emissions. The total amount of emissions from the B738 type of aircraft is estimated as 24%. It is noticed that the taxi phase constitutes 52% of the total HC, CO and NOx emissions. Because of this, it is selected the five different alternative taxi times to observe the effects of pollution role of taxiing time in detail and re-estimated accordingly. According to the re-estimated results with variations in taxiing time, when the taxiing time at the airport is 24 min instead of the original value, this case contributes to a decrease in total LTO emissions of approximately 4%. Also, when the taxiing time is decreased by 2 min, HC, CO and NOx emission amounts decrease by approximately 3.9%, 5.9% and 1.2%, respectively. At this point, the polluting role of taxiing time will be helpful to reduce the aircraft-induced HC, CO and NOx emissions for other larger-scale airports. On the other hand, it is estimated that the GWP of the A321 is 1,066.29 t CO2e whilst the GWP of B738 is 719.50 t CO2e. The eco-cost values of the A321, B738, A320 and CL60-type of aircraft are estimated as almost 61,049.42, 41,086.02, 18,417.43 and 6,163.59 Euros, respectively.

Practical implications

With the detailed results of this study, the polluting role of taxiing time on total HC, CO and NOx emissions in a small-scale airport will be helpful to reduce aircraft-induced emissions for other larger-scale airports. Also, in the future, this study and its results will be helpful to create an emission inventory at the airport examined.

Originality/value

In this study, different from some previous studies, air pollutants from aircrafts are evaluated with different aspects such as the EI and eco-cost and GWP. Also, this study will be making a helpful contribution to the literature as it covers the more diversity of the different types of aircrafts in the analyses.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 2
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 1 February 1997

N.J. Sanders

Stainless steel pickling is a major generator of NOx emissions and is also a major producer of nitrate effluents. Hydrogen peroxide technologies have been developed and proven to…

1136

Abstract

Stainless steel pickling is a major generator of NOx emissions and is also a major producer of nitrate effluents. Hydrogen peroxide technologies have been developed and proven to suppress NOx emissions and also to replace nitric acid in the pickling process and hence remove the problem of nitrate effluent discharge. Presents case histories to illustrate the effectiveness of hydrogen peroxide both for NOx suppression and for nitric acid‐free pickling when pickling stainless steels.

Details

Anti-Corrosion Methods and Materials, vol. 44 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 5 January 2015

Ravindra Kumar, Purnima Parida, Surbhi Shukla and Wafaa Saleh

– The purpose of this paper is to estimate total emission during idling of vehicles and validate emission results from real-world data.

Abstract

Purpose

The purpose of this paper is to estimate total emission during idling of vehicles and validate emission results from real-world data.

Design/methodology/approach

Motor Vehicle Emission Simulator (MOVES)2010b emission model is customised for developing country like India and a case study of the Ashram intersection in Delhi has been selected in order to measure the emissions of vehicles during idling.

Findings

Results show that 3.997 mg/m3 of hydrocarbon, 1.82 mg/m3 of NOx and 17.688 mg/m3 of carbon monoxide is emitted from the cars, trucks and buses, respectively, at Ashram intersection in one day. As there are 600 intersections throughout Delhi, a total of 2,398.055 mg/m3 of hydrocarbon, 1,087.068 mg/m3 of NOx and 10,612.612 mg/m3 of carbon monoxide is emitted from cars, trucks and buses in a day in all of Delhi.

Originality/value

Knowledge of idling emission and fuel loss is very little for Indian traffic condition during delays.

Details

World Journal of Science, Technology and Sustainable Development, vol. 12 no. 1
Type: Research Article
ISSN: 2042-5945

Keywords

Article
Publication date: 31 July 2020

Hasim Kafali and Onder Altuntas

This study aims to present atmospheric emissions (NOx, CO and HC) of commercial flights at Dalaman Airport for the years between 2016 and 2018.

Abstract

Purpose

This study aims to present atmospheric emissions (NOx, CO and HC) of commercial flights at Dalaman Airport for the years between 2016 and 2018.

Design/methodology/approach

Growing up, the potential for domestic and international airports will cause an increase in air transportation. Increasing demand for air transportation will cause adverse environmental impacts as well as positive economic contributions. Finding negative environmental effects and searching for solutions is an essential first step.

Findings

Emissions were calculated under three different groups (as daily, number of flights and per passenger). The maximum CO emission calculated was 1031.71 kg/day in August 2018, 41.55 g/pax. in October 2016 and 6909.27 g/flight in August 2018. The maximum HC emission calculated was 117.22 kg/day in August 2018, 4.78 g/pax. in May 2018 and 796.47 g/flight in May 2018. The maximum NOx emission calculated was 148.63 kg/day in August 2018, 6.04 g/pax. in October 2017 and 995.34 g/flight in August 2018.

Practical implications

The current study intends to show how can emission results differ under three different units.

Originality/value

The originality is the using of the real-time values for all calculations. The value of this study is to be key study for future applications of emission calculation methodologies.

Details

Aircraft Engineering and Aerospace Technology, vol. 92 no. 10
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 10 November 2020

Jonathan Spiteri and Philip von Brockdorff

The aim of this paper is to quantify the impact of transboundary air pollutants, particularly those related to urban traffic, on health outcomes. The importance of focusing on the…

Abstract

Purpose

The aim of this paper is to quantify the impact of transboundary air pollutants, particularly those related to urban traffic, on health outcomes. The importance of focusing on the health implications of transboundary pollution is due to the fact that these emissions originate from another jurisdiction, thus constituting international negative externalities. Thus, by isolating and quantifying the impact of these transboundary air pollutants on domestic health outcomes, the authors can understand more clearly the extent of these externalities, identify their ramifications for health and emphasise the importance of cross-country cooperation in the fight against air pollution.

Design/methodology/approach

The authors employ panel data regression analysis to look at the relationship between emissions of transboundary air pollution and mortality rates from various respiratory diseases among a sample of 40 European countries, over the period 2003–2014. In turn, the authors use annual data on transboundary emissions of sulphur oxides (SOx), nitrogen oxides (NOx) and fine particulate matter (PM2.5), together with detailed data on the per capita incidence of various respiratory diseases, including lung cancer, asthma and chronic obstructive pulmonary disease (COPD). The authors consider a number of different regression equation specifications and control for potential confounders like the quality of healthcare and economic prosperity within each country.

Findings

The results show that transboundary emissions of PM2.5 are positively and significantly related to mortality rates from asthma in our sample of countries. Quantitatively, a 10% increase in PM2.5 transboundary emissions per capita from neighbouring countries is associated with a 1.4% increase in the asthma mortality rate within the recipient country or roughly 200 deaths by asthma per year across our sample.

Originality/value

These findings have important policy implications for cross-country cooperation and regulation in the field of pollution abatement and control, particularly since all the countries under consideration form a part of the UN's Convention on Long-Range Transboundary Air Pollution (CLRTAP), a transnational cooperative agreement aimed at curtailing such pollutants on an international level.

Details

Journal of Economic Studies, vol. 48 no. 7
Type: Research Article
ISSN: 0144-3585

Keywords

Article
Publication date: 11 November 2020

Booma Devi, Venkatesh S., Rakesh Vimal and Praveenkumar T.R.

This paper aims to investigate the effect of additives in Jet-A fuel blends, especially on performance, combustion and emission characteristics.

Abstract

Purpose

This paper aims to investigate the effect of additives in Jet-A fuel blends, especially on performance, combustion and emission characteristics.

Design/methodology/approach

Jet-A fuel was formed by using Kay’s and Gruenberg–Nissan mixing rules by adding additive glycerol with TiO2. While measuring the combustion performance, the amount of oxygen content present in fuel and atomization are the key factors to consider. As such, the Jet-A fuel was created by adding additives at different proportion. A small gas turbine engine was used for conducting tests. All tests were carried out at different load conditions for all the fuel blends such as neat Jet-A fuel, G10T (glycerol 10% with 50 ppm TiO2 and Jet-A 90%), G20T (glycerol 10% with 50 ppm TiO2 and Jet-A 90%) and G30T (glycerol 10% with 50 ppm TiO2 and Jet-A 90%).

Findings

From tests, the G20T and G10T produced better results than other blends. The thermal efficiency of the blends of G20T and G10T are 22% and 14% higher than neat Jet-A fuel. Further, the improved static thrust with less fuel consumption was noticed in G20T fuel blend.

Originality/value

The G20T blends showed better performance because of the increased oxygenated compounds in the fuel blends. Moreover, the emission rate of environmentally harmful gases such as NOx, CO and HC was lower than the neat Jet-A fuel. From the results, it is clear that the rate of exergy destruction is more in the combustion chamber than the other components of fuel.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 3
Type: Research Article
ISSN: 1748-8842

Keywords

Open Access
Article
Publication date: 1 June 2021

S.V. Khandal, T.M. Yunus Khan, Sarfaraz Kamangar, Maughal Ahmed Ali Baig and Salman Ahmed N J

The different performance tests were conducted on diesel engine compression ignition (CI) mode and CRDi engine.

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Abstract

Purpose

The different performance tests were conducted on diesel engine compression ignition (CI) mode and CRDi engine.

Design/methodology/approach

The CI engine was suitably modified to CRDi engine with Toroidal re-entrant combustion chamber (TRCC) and was run in dual-fuel (DF) mode. Hydrogen (H2) was supplied at different flow rates during the suction stroke, and 0.22 Kg/h of hydrogen fuel flow rate (HFFR) was found to be optimum. Diesel and biodiesel were used as pilot fuels. The CRDi engine with DF mode was run at various injection pressures, and 900 bar was found to be optimum injection pressure (IP) with 10o before top dead center (bTDC) as fuel injection timing (IT).

Findings

These operating engine conditions increased formation of oxides of nitrogen (NOx), which were reduced by exhaust gas recycle (EGR). With EGR of 15%, CRDi engine resulted in 12.6% lower brake thermal efficiency (BTE), 5.5% lower hydrocarbon (HC), 7.7% lower carbon monoxide (CO), 26% lower NOx at 80% load as compared to the unmodified diesel engine (CI mode).

Originality/value

The current research is an effort to study and evaluate the performance of CRDi engine in DF mode with diesel-H2 and BCPO-H2 fuel combinations with TRCC.

Details

Frontiers in Engineering and Built Environment, vol. 1 no. 1
Type: Research Article
ISSN: 2634-2499

Keywords

Article
Publication date: 1 March 2012

Katriina Parikka-Alhola and Ari Nissinen

The “most economically advantageous tender,” as defined in the EUʼs public procurement directives, allows public purchasers to combine environmental aspects, price and other award…

Abstract

The “most economically advantageous tender,” as defined in the EUʼs public procurement directives, allows public purchasers to combine environmental aspects, price and other award criteria in decision making. The directives do not, however, determine how the environmental criteria should be built. Indeed, there could be different means to assess the “greenness” of competing tenders, and these various measurements of environmental impacts may lead to different assessments of the most economically advantageous tender. In this article, the determination of environmental award criteria is examined through a case study on a purchase of a goods transportation service, where the most economically advantageous tender is calculated by life cycle assessment and the environmental cost calculation method suggested by the EU, and compared to the results gained by the purchaserʼs equation. Also the contribution of the weighting for the “green” purchasing decision is discussed.

Details

Journal of Public Procurement, vol. 12 no. 1
Type: Research Article
ISSN: 1535-0118

Article
Publication date: 1 January 2014

Asis Sarkar

This paper aims to evaluate nine types of electrical energy generation options with regard to seven criteria. The analytic hierarchy process (AHP) was used to perform the…

Abstract

Purpose

This paper aims to evaluate nine types of electrical energy generation options with regard to seven criteria. The analytic hierarchy process (AHP) was used to perform the evaluation. The TOPSIS method was used to evaluate the best generation technology.

Design/methodology/approach

The options that were evaluated are the hydrogen combustion turbine, the hydrogen internal combustion engine, the hydrogen fuelled phosphoric acid fuel cell, the hydrogen fuelled solid oxide fuel cell, the natural gas fuelled phosphoric acid fuel cell, the natural gas fuelled solid oxide fuel cell, the natural gas turbine, the natural gas combined cycle and the natural gas internal combustion engine. The criteria used for the evaluation are CO2 emissions, NOX emissions, efficiency, capital cost, operation and maintenance costs, service life and produced electricity cost.

Findings

The results drawn from the analysis in technology wise are as follows: natural gas fuelled solid oxide fuel cells>natural gas combined cycle>natural gas fuelled phosphoric acid fuel cells>natural gas internal combustion engine>hydrogen fuelled solid oxide fuel cells>hydrogen internal combustion engines>hydrogen combustion turbines>hydrogen fuelled phosphoric acid fuel cells> and natural gas turbine. It shows that the natural gas fuelled solid oxide fuel cells are the best technology available among all the available technology considering the seven criteria such as service life, electricity cost, O&M costs, capital cost, NOX emissions, CO2 emissions and efficiency of the plant.

Research limitations/implications

The most dominant electricity generation technology proved to be the natural gas fuelled solid oxide fuel cells which ranked in the first place among nine alternatives. The research is helpful to evaluate the different alternatives.

Practical implications

The research is helpful to evaluate the different alternatives and can be extended in all the spares of technologies.

Originality/value

The research was the original one. Nine energy generation options were evaluated with regard to seven criteria. The energy generation options were the hydrogen combustion turbine, the hydrogen internal combustion engine, the hydrogen fuelled phosphoric acid fuel cell, the hydrogen fuelled solid oxide fuel cell, the natural gas fuelled phosphoric acid fuel cell, the natural gas fuelled solid oxide fuel cell, the natural gas turbine, the natural gas combined cycle and the natural gas internal combustion engine. The criteria used for the evaluation were efficiency, CO2 emissions, NOX emissions, capital cost, O&M costs, electricity cost and service life.

Details

International Journal of Quality & Reliability Management, vol. 31 no. 1
Type: Research Article
ISSN: 0265-671X

Keywords

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