Onder Altuntas

Exergoenvironmental analysis of piston–prop aircrafts

This study deals with exergoenvironmental analysis of a four–cylinder, spark ignition, naturally aspirated and air–cooled piston–prop aircraft engine for landing takeoff (LTO) and cruise phases. This analysis includes the three steps as follows: application of exergy analysis, finding the exergoenvironmental impacts, and allocation of both exergy streams and exergoenvironmental impacts. In the LTO phase, the maximum specific environmental impact and relative environmental difference is calculated as 18.8 mPts/MJ and 208.9%, respectively, at the approach phase. The maximum specific environmental impact of production is 12.2 mPts/MJ at 3000 m altitude, 15.1 air–to–fuel ratio and 65% rated power setting during the cruise phase.

Assessment of thermodynamic performance and exergetic sustainability of turboprop engine using mixture of kerosene and methanol

In this study, first and second laws of thermodynamics were performed in the turboprop and is analysed and discussed with the mathematical model of sustainability performance of a turboprop engine using a mixture of alternative fuel (Methanol CH3OH) and conventional fuel (Kerosene C12H26). The results showed when the excess air is kept constant, with the increases of the alternative fuel, mixture is enriched with oxygen as a source of methanol and the actual air-fuel ratio decreased was determined. When the rate of alternative fuel in mixture was increased, it was observed that the fuel flow started to increase, because Lower Heating Value of methanol is lower than kerosene. Therefore, increasing of fuel consumption was found to obtain the same power in propeller as negative effect. ESIs - waste exergy ratio, exergy destruction factor and environmental effect factor - is increased with the increasing ratio of methanol in the mixture.

Calculation of HC, CO and NOx from civil aviation in Turkey in 2012

To meet the growing demand for air transport, airline companies doubled their aircraft numbers in Turkey, where civil aviation activities have shown great development in recent years. This increase in aircraft numbers resulted in an emission problem. Considering its impact on regional air quality, the growing emission amounts are at a non-negligible level. We especially take the busiest airports in Turkey into account, as these airports are generally located in widely populated areas. In this study, HC, CO, and NOx emission during the LTO for the selected five busiest airports were calculated by taking the 2012 domestic data of: 1) the General Directorate of State Airports Authority in Turkey; 2) EUROCONTROL’s average taxi time; 3) emission factors of ICAO engine datasheets. The calculated emission amounts are 215 tons/year, 1,483 tons/year, 1,417 tons/year, HC, CO, NOx respectively and the biggest emission factor is found to be as CO. Among the airports, Istanbul Ataturk Airport has the biggest polluting...

Calculation of domestic flight-caused global warming potential from aircraft emissions in Turkish airports

In this study, global warming potential (GWP) is calculated for aircrafts used in Turkish airports. The basic idea of this study is to investigate both emissions and their GWP values. This study is conducted in three steps, namely: 1) finding busiest airports in Turkey; 2) specifying the most used aircraft types and its engines; and 3) calculation of domestic flight-caused GWP value for both the total number of aircraft and per-passenger evaluation. In this regard, the Intergovernmental Panel on Climate Change (IPCC) 2007 GWP 100a methodology is utilised along with the method of the life cycle assessment. While the total average GWP value is 1,629 kg carbon dioxide equivalent (CO 2 e) per landing and takeoff (LTO), the total domestic flight-caused GWP value was calculated as 257,305 tons of CO 2 e per year in 2002 and 998,118 tons of CO 2 e per year in 2012. While, the last two years have had an average value of 12–13 kg CO 2 e per passenger for one airport, the GWP values per passenger have averaged 15.35 kg CO 2 e per passenger, per airport over these years.

Performance Evaluation of an Experimental Turbojet Engine

Abstract An exergy analysis is presented including design parameters and performance assessment, by identifying the losses and efficiency of a gas turbine engine. The aim of this paper is to determine the performance of a small turbojet engine with an exergetic analysis based on test data. Experimental data from testing was collected at full-load of small turbojet engine. The turbojet engine exhaust data contains CO2, CO, CH4, H2, H2O, NO, NO2, N2 and O2 with a relative humidity of 35 % for the ambient air of the performed experiments. The evaluated main components of the turbojet engine are the air compressor, the combustion chamber and the gas turbine. As a result of the thermodynamic analysis, exergy efficiencies (based on product/fuel) of the air compressor, the combustion chamber and the gas turbine are 81.57 %, 50.13 % and 97.81 %, respectively. A major proportion of the total exergy destruction was found for the combustion chamber at 167.33 kW. The exergy destruction rates are 8.20 %, 90.70 % and 1.08 % in the compressor, the combustion chamber and the gas turbine, respectively. The rates of exergy destruction within the system components are compared on the basis of the exergy rate of the fuel provided to the engine. Eventually, the exergy rate of the fuel is calculated to be 4.50 % of unusable due to exergy destruction within the compressor, 49.76 % unusable due to exergy destruction within the combustion chamber and 0.59 % unusable due to exergy destruction within the gas turbine. It can be stated that approximately 55 % of the exergy rate of the fuel provided to the engine can not be used by the engine.

A Parametric Study of a Piston-Prop Aircraft Engine Using Exergy and Exergoeconomic Analysis Methods

In this study, exergetic and exergoeconomic analysis methods are applied to a four-cylinder, spark ignition (SI), naturally aspirated and air-cooled piston-prop aircraft engine in the cruise phase of flight operations. The duration of cruise is selected to be 1 h. Three parameters, altitude, rated power setting (PS), and air-to-fuel ratio (AF), are varied by the calculation of the max–min values of exergy analysis. Based on the results of energy analysis, the values for the maximum energy efficiency and fuel consumption flow rate are calculated to be 21.73% and 28.02 kg/h, respectively, at 1000-m altitude and 75% PS. The results of exergy analysis indicate that all exergetic values vary from 65% to 75% PS, while this increase is not seen in exergoeconomic analysis. While the maximum exergy input rate is obtained to be 405.60 kW, exergy efficiency has the minimum value with 14.43% and exergy destruction rate has the maximum value with 168.48 kW. These values are achieved at 3000-m altitude and 18 AFs. The maximum average exergy cost of the fuel is calculated to be 130.77

Sustainability Metrics of a Small Scale Turbojet Engine

/GJ at 1000-m altitude, 13 AF ratios, and 65% PS. At this point, while the minimum cost rate associated with the exergy destruction is obtained to be 40.29

Exergoeconomic Environmental Optimization of Piston-Prop Aircraft Engines

/h, the maximum exergoeconomic factor is found to be 19.98%.

Investigation of environmental impact caused by aircraft engines

Abstract Over the last decade, sustainable energy consumption has attracted the attention of scientists and researchers. The current paper presents sustainability indicators of a small scale turbojet engine, operated on micro-aerial vehicles, for discussion of the sustainable development of the aviation industry from a different perspective. Experimental data was obtained from an engine at full power load and utilized to conduct an exergy-based sustainability analysis. Exergy efficiency, waste exergy ratio, recoverable exergy ratio, environmental effect factor, exergy destruction factor and exergetic sustainability index are evaluated as exergetic sustainability indicators of the turbojet engine under investigation in the current study. The exergy efficiency of the small scale turbojet engine is calculated as 27.25 % whereas the waste exergy ratio, the exergy destruction factor and the sustainability index of the engine are found to be 0.9756, 0.5466 and 0.2793, respectively.

Exergy and Energy Analysis of an Aircraft Air Cycle Machine at Designated Altitude

In this study, exergy, exergoeconomic, exergoenvironmental analyses, and exergoeconomic environmental optimization are applied to a four-cylinder, spark ignition, naturally aspirated and air-cooled piston-prop aircraft engine in the cruise phase of flight for the first time to the best of the authors` knowledge. Here, three piston-prop aircraft engine parameters (altitude, air–fuel ratio (AF), and rated power setting (PS)) are selected for optimization purposes. All exergy, exergoeconomic, and exergoenvironmental values are calculated first. These values are then optimized to find the best results of all analyses. The best altitude, AF ratio, and PS values are finally found while the maximum exergy efficiency, the minimum product specific environmental impact, and the minimum average unit fuel exergy cost are obtained. The best results of optimization indicated that the maximum exergy efficiency varied between 19.54% and 19.80%, the minimum unit fuel exergy cost ranged from 126.30