AN ANALYSIS OF THE EFFECT OF NON-PAYLOAD WEIGHT ON FUEL CONSUMPTION FOR A WIDE-BODIED AIRCRAFT

Fuel flow rate of an aircraft varies significantly during a typical flight, mainly due to required engine thrust, weather conditions, aircraft configuration and aircraft mass. Of these, the effect of aircraft mass, being the non-payload portion, on fuel flow is investigated in this study. The investigation is carried out for twin-engined wide-bodied aircraft, during its intercontinental flights. Based on actual flight data records, two approaches are developed, in which the fuel flow rate is estimated based on three independent variables; altitude, aircraft mass and flight speed. The regression models are found to be highly significant and average fuel consumption is found to be 2-3% of the non-payload mass per flight hour. It should be noted that this percentage is affected by flight altitude and aircraft initial mass, of which the latter has a greater effect. In addition, it is worth noting that when the aircraft initial mass increases, the fuel consumption percentage also tends to increase

AN ANALYSIS OF VERTICAL PROFILES OF WIND AND HUMIDITY BASED ON LONG-TERM RADIOSONDE DATA IN TURKEY

The prediction of atmospheric variables is fundamentally important for flight, and efficiency with environmental impact analyses of aircraft. However, certain variables are less predictable leading to inefficient utilization of limited resources. To maximize the efficiency of aviation systems more accurate approaches are required to increase the predictability of these variables. One of these variables, wind aloft is analyzed in this study, with altitude, season and location, based on data obtained from eight radiosonde stations operating in Turkey. It is found that as altitude increases, wind direction approximates to 270° in a clockwise direction. Wind speed appears to be quadratically (or cubic for higher accuracy) proportional with altitude and maximum average wind speed is observed in March. It should be noted that relative humidity decreases linearly with an increase in altitude at an average of 4% per kilometer

Exergetic analysis of an aircraft turbofan engine

WOS: 000250813800003The main objective of the present study is to perform an exergy analysis of a turbofan kerosene-fired engine with afterburner (AB) at sea level and an altitude of 11000 m. The main components of this engine include a fan, a compressor, a combustion chamber, a turbine, an AB and an exhaust. Exergy destructions in each of the engine components are determined, while exergy efficiency values for both altitudes are calculated. The AB unit is found to have the highest exergy destruction with 48.1% of the whole engine at the sea level, followed by the exhaust, the combustion chamber and the turbine amounting to 29.7, 17.2 and 2.5%, respectively. The corresponding exergy efficiency values for the four components on the product/fuel basis are obtained to be 59.9, 65.6, 66.7 and 88.5%, while those for the whole engine at the sea level and an altitude of 11000 m are calculated to be 66.1 and 54.2%. Copyright (c) 2007 John Wiley & Sons, Ltd

Exergoeconomic analysis of an aircraft turbofan engine

WOS: 000267086200001This study deals with an exergoeconomic analysis of an aircraft turbofan engine utilising the kerosene as fuel. A new parameter is developed to define the trust cost rate. The cost of exergy destruction, the relative cost difference and the exergoeconomic factor are investigated. The variation of the relative cost difference and exergoeconomic factor according to the operating and maintenance costs and the annual operating hour are also studied. For a high by-pass and high thrust rated engine, the cost rate of thrust is obtained to be 304.35 $(hkN)(-1) for the hot thrust and 138.96$(hkN)(-1) for the cold thrust, respectively

Exergy analysis of a turbofan aircraft engine

WOS: 000265449200003An exergy analysis is reported for a General Electric turbofan engine (the CF6-80) using sea-level data. The effects on exergy efficiencies and exergy destructions are investigated of modifying the isentropic efficiencies of turbomachinery components. The most irreversible units in the system are found to be the fan and the core engine exhaust, with exergy loss rates of 47.3 MW and 35.9 MW, respectively, and the combustion chamber, with an exergy destruction rate of 31.5 MW. The exergy efficiencies of the fan and the core engine exhausts are found to be 12.9 and 12.7%, respectively

Elemental characterization of general aviation aircraft emissions using moss bags

In light of growing concern and insufficient knowledge on the negative impact of aircraft emissions on environmental health, this study strives to investigate the air burden of major and trace elements caused by general aviation, piston-engine, and turboprop aircraft, within the vicinity of Eskisehir Hasan Polatkan Airport (Eskisehir, Turkey). The levels of 57 elements were investigated, based on moss bag biomonitoring using Sphagnum sp., along with chemical analyses of lubrication oil and aviation gasoline fuel used in the aircraft's operations. Five sampling sites were selected within the vicinity of the airport area to capture spatial changes in the concentration of airborne elements. The study demonstrates that moss bag biomonitoring is a useful tool in the identification of differences in the air burden by major and trace elements that have concentrated downwind of the aircraft emission sources. Moreover, pollutant enrichment in the Sphagnum moss bags and elemental characterization of oil/fuel are in agreement suggesting that Pb, followed by Cd, Cu, Mo, Cr, Ni, Fe, Si, Zn, Na, P, Ca, Mg, and Al are dominant elements that shaped the general aviation aircraft emissions