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Article
Publication date: 2 September 2014

Ugur Ozsarac, Salim Aslanlar, Faruk Varol and Mehmet Ekici

The purpose of this study was to investigate wear behaviours of brake pads produced from carbon–carbon (C/C) composites in both wet and dry friction sliding conditions. Carbon is…

861

Abstract

Purpose

The purpose of this study was to investigate wear behaviours of brake pads produced from carbon–carbon (C/C) composites in both wet and dry friction sliding conditions. Carbon is probably the most remarkable element in science and also C/C composites are a family of advanced composite materials. They are the most advanced form of carbon and consist of fibre based on carbon precursors embedded in a carbon matrix. In the present work, wear test specimens were prepared according to the related standards and they were exposed to pin-on-disc wear testing in wet and dry sliding conditions with different loads as 10, 20, 30 and 40 N with 1 m/s constant sliding speed. Wet friction process was conducted on all specimens by means of rain water collected from the nature.

Design/methodology/approach

Pin-on-disc wear test tribology lubrication was used.

Findings

Mechanical and physical property measurements of C/C composite brake pad materials: hardness, modulus of elasticity, density and water absorption capacity. Wear performance of materials were measured as coefficient of friction, volumetric loss and specific wear rate.

Originality/value

C/C composite brake pads are used in railway vehicles. Wear performances of them are very important for safety. In this study, wear behaviours of these materials were investigated not only in dry sliding friction condition but also in wet sliding one. Because safety braking is important in all weather conditions for trains, and we used natural rain water to observe the wet sliding friction behaviour of brake pads. “Water lubrication” is an important aspect mentioned in tribology handbooks.

Details

Industrial Lubrication and Tribology, vol. 66 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 12 July 2022

Mehmet Kadri Akyüz

The purpose of this study is to determine and compare the total and per passenger HC, CO, NOx and CO2 emissions from aircraft landing and takeoff (LTO) cycle before and during the…

239

Abstract

Purpose

The purpose of this study is to determine and compare the total and per passenger HC, CO, NOx and CO2 emissions from aircraft landing and takeoff (LTO) cycle before and during the COVID-19 pandemic. In addition, it is aimed to determine the global warming potential (GWP), environmental impacts (EIs) and enviroeconomic cost (eco-cost) of these emissions in total and per passenger.

Design/methodology/approach

Analyses were carried out with the help of the International Civil Aviation Organization’s Engine Emission Databank, using real flight data recorded by the airport authority.

Findings

During the COVID-19 pandemic, total pollutant emissions (HC, CO, NOx and CO2) decreased between 23.7% and 30.8% compared with the pre-pandemic period. In addition, per passenger pollutant emissions increased during the pandemic. Compared with the pre-pandemic period, GWP, EI and eco-cost values decreased by 24.1%, 23.89% and 23.93%, respectively, in the pandemic. However, the per passenger GWP, EI and eco-cost values increased by about 10% compared with the pre-pandemic period.

Practical implications

This study reveals the effects of COVID-19 in terms of EIs and environmental costs caused by aircraft in the LTO cycle.

Originality/value

The originality of this study is to calculate the pollutant emissions caused by aircraft in the LTO cycle with real flight data and to reveal the effects of the COVID-19 pandemic. The novelty of this study is the determination and comparison of total and per passenger pollutant emissions, GWP, EI and eco-cost before and during the pandemic.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 8
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 5 August 2024

Mehmet Ziya Sogut

The altitude and weather conditions affect directly fuel consumption and engine efficiency of the aircraft engines. The thermo-physical properties of the weather of altitude play…

41

Abstract

Purpose

The altitude and weather conditions affect directly fuel consumption and engine efficiency of the aircraft engines. The thermo-physical properties of the weather of altitude play a significant role in this process. Unfortunately, engine performance based on altitude conditions also causes waste heat and environmental pollution due to engine entropy generation. However, environmental impact assessment is needed to improve environmental sustainability. This study aimed to analyse the energy and environmental performance of a piston engine based on altitude conditions.

Design/methodology/approach

This study is based on the entropy approach, and it aims to assess the environmental impact of the engine. Exergy analysis with together two new indices to evaluate the environmental effects caused by the engine under altitude conditions was used.

Findings

The analysis reveals that the exergy efficiency of the piston engine is 23.9% on average for the three referenced altitudes, while the exergy efficiency difference between altitude boundary conditions is 11%. In addition, the entropy production of the engine is on average 10.55 kW/K. In this case, the environmental pollution potential resulting from the entropy production of the engine is on average 3.29 times higher due to reversible conditions, while the improvement rate was found to be 58%.

Originality/value

This analysis shows that engine efficiency increases as altitude increases. Similarly, it can also be said that the environmental impacts are reduced and the improvement of the engine has opportunities for operational processes. Besides, in the study, some suggestions for motor performance impact analysis were presented.

Details

Aircraft Engineering and Aerospace Technology, vol. 96 no. 7
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 12 July 2021

Mehmet Ziya Sogut

This study aims to examine exergy efficiency of engines and entropy performances at the flight process. In addition, the improvements that can be achieved in the system with the…

116

Abstract

Purpose

This study aims to examine exergy efficiency of engines and entropy performances at the flight process. In addition, the improvements that can be achieved in the system with the effective parametric controls of the engine have been evaluated in terms of both efficiency and entropy in the system.

Design/methodology/approach

According to the flight characteristics of the engine, the altitude-dependent irreversibilities and their environmental effects were discussed with two developed indicators, energy performance indicator (EPI) and sustainability indicator (SI).

Findings

According to the results of both indicators, the energy efficiency potential of the engine during the flight process was found to be 15.02%, while the fuel-based efficiency potential was 18.84%.

Research limitations/implications

It is limited by the flight process of a Turboprop engine.

Practical implications

The management tools and criteria of entropy are very difficult model studies. The study offers an evaluable approach based on two basic criteria developed for engines.

Social implications

In monitoring and review of entropy management related to fossil fuel technologies, key indicators developed can be used as benchmarks for managing emission sources

Originality/value

The two basic indicators developed can be used as monitoring measurement tools of sustainable energy and environmental performances for engines and applications.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 8
Type: Research Article
ISSN: 1748-8842

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Book part
Publication date: 24 June 2024

Buğcan Güvenol and Mehmet Emre Güler

Throughout history, battlefield sites have continued to develop within the scope of tourism activities, primarily through the support of both official and nonofficial…

Abstract

Throughout history, battlefield sites have continued to develop within the scope of tourism activities, primarily through the support of both official and nonofficial institutions. The nature of these institutions may vary depending on their country or type. In this section, examples of institutions are examined in a general framework according to countries and the activities undertaken by these institutions to support battlefield tourism. Examples can be further multiplied, but it should be kept in mind that the ministries of the countries, especially those related to tourism, or the local administrations where the battlefield is located, will support this type of tourism rather than the examples given. In conclusion, institutions generally contribute to battlefield sites by organizing commemorative events, tours, and educational programs, safeguarding areas through restoration efforts, and disseminating information about these sites. All these activities carried out by these institutions not only contribute to battlefield tourism but also serve to raise awareness among individuals about battlefield sites.

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Article
Publication date: 22 October 2021

Mehmet Kadri Akyüz

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…

403

Abstract

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.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 3
Type: Research Article
ISSN: 1748-8842

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Book part
Publication date: 24 June 2024

Kaan Kasaroğlu and Simge Kömürcü Sarıbaş

Wars all over the world have changed the course of history, affected communities and ways of life, and caused much pain, sadness, and destruction. Today, these areas are seen as…

Abstract

Wars all over the world have changed the course of history, affected communities and ways of life, and caused much pain, sadness, and destruction. Today, these areas are seen as tourist attractions and are visited by many people with different motivations every year. In these travels, which are described as battlefield tourism, intermediary institutions serve as a bridge between the consumer and the producer, in other words, between the tourist and the touristic product. In this section, first the factors that have led people to travel throughout history are discussed, and then the history, purposes, activities, and importance and contributions of intermediary institutions within the tourism industry are explained. Afterward, battlefield tourism, a relatively new concept, was mentioned, and the importance of intermediary institutions in travels to battlefields was explained. Finally, intermediary institutions that organize tours to various major battlefields in the world are listed, and brief descriptive information is given about the wars in question and the tours organized to these areas.

Details

Battlefield Tourism
Type: Book
ISBN: 978-1-83909-991-5

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Article
Publication date: 15 February 2023

Mehmet Necati Cizrelioğullari, Tapdig Veyran Imanov, Tugrul Gunay and Aliyev Shaiq Amir

Temperature anomalies in the upper troposphere have become a reality as a result of global warming, which has a noticeable impact on aircraft performance. The purpose of this…

157

Abstract

Purpose

Temperature anomalies in the upper troposphere have become a reality as a result of global warming, which has a noticeable impact on aircraft performance. The purpose of this study is to investigate the total air temperature (TAT) anomaly observed during the cruise level and its impact on engine parameter variations.

Design/methodology/approach

Empirical methodology is used in this study, and it is based on measurements and observations of anomalous phenomena on the tropopause. The primary data were taken from the Boeing 747-8F's enhanced flight data recorder, which refers to the quantitative method, while the qualitative method is based on a literature review and interviews. The GEnx Integrated Vehicle Health Management system was used for the study's evaluation of engine performance to support the complete range of operational priorities throughout the entire engine lifecycle.

Findings

The study's findings indicate that TAT and SAT anomalies, which occur between 270- and 320-feet flight level, have a substantial impact on aircraft performance at cruise altitude and, as a result, on engine parameters, specifically an increase in fuel consumption and engine exhaust gas temperature values. The TAT and Ram Rise anomalies were the focus of the atmospheric deviations, which were assessed as major departures from the International Civil Aviation Organizations–defined International Standard Atmosphere, which is obvious on a positive tendency and so goes against the norms.

Research limitations/implications

Necessary fixed flight parameters gathered from the aircraft's enhanced airborne flight recorder (EAFR) via Aeronautical Radio Incorporated (ARINC) 664 Part 7 at a certain velocity and altitude interfacing with the diagnostic program direct parameter display (DPD), allow for analysis of aircraft performance in a real-time frame. Thus, processed data transmits to the ground maintenance infrastructure for future evaluation and for proper maintenance solutions.

Originality/value

A real-time analysis of aircraft performance is possible using the diagnostic program DPD in conjunction with necessary fixed flight parameters obtained from the aircraft's EAFR via ARINC 664 Part 7 at a specific speed and altitude. Thus, processed data is transmitted to the ground infrastructure for maintenance to be evaluated in the future and to find the best maintenance fixes.

Details

Aircraft Engineering and Aerospace Technology, vol. 96 no. 8
Type: Research Article
ISSN: 1748-8842

Keywords

Available. Content available
Book part
Publication date: 30 July 2018

Abstract

Details

Marketing Management in Turkey
Type: Book
ISBN: 978-1-78714-558-0

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Article
Publication date: 7 March 2023

Sedat Metlek

The purpose of this study is to develop and test a new deep learning model to predict aircraft fuel consumption. For this purpose, real data obtained from different landings and…

467

Abstract

Purpose

The purpose of this study is to develop and test a new deep learning model to predict aircraft fuel consumption. For this purpose, real data obtained from different landings and take-offs were used. As a result, a new hybrid convolutional neural network (CNN)-bi-directional long short term memory (BiLSTM) model was developed as intended.

Design/methodology/approach

The data used are divided into training and testing according to the k-fold 5 value. In this study, 13 different parameters were used together as input parameters. Fuel consumption was used as the output parameter. Thus, the effect of many input parameters on fuel flow was modeled simultaneously using the deep learning method in this study. In addition, the developed hybrid model was compared with the existing deep learning models long short term memory (LSTM) and BiLSTM.

Findings

In this study, when tested with LSTM, one of the existing deep learning models, values of 0.9162, 6.476, and 5.76 were obtained for R2, root mean square error (RMSE), and mean absolute percentage error (MAPE), respectively. For the BiLSTM model when tested, values of 0.9471, 5.847 and 4.62 were obtained for R2, RMSE and MAPE, respectively. In the proposed hybrid model when tested, values of 0.9743, 2.539 and 1.62 were obtained for R2, RMSE and MAPE, respectively. The results obtained according to the LSTM and BiLSTM models are much closer to the actual fuel consumption values. The error of the models used was verified against the actual fuel flow reports, and an average absolute percent error value of less than 2% was obtained.

Originality/value

In this study, a new hybrid CNN-BiLSTM model is proposed. The proposed model is trained and tested with real flight data for fuel consumption estimation. As a result of the test, it is seen that it gives much better results than the LSTM and BiLSTM methods found in the literature. For this reason, it can be used in many different engine types and applications in different fields, especially the turboprop engine used in the study. Because it can be applied to different engines than the engine type used in the study, it can be easily integrated into many simulation models.

Details

Aircraft Engineering and Aerospace Technology, vol. 95 no. 5
Type: Research Article
ISSN: 1748-8842

Keywords

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