Energetic, exergetic, exergoeconomic, environmental (4E) and sustainability performances of an unmanned aerial vehicle micro turbojet engine

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ozgur Balli ◽  
Alper Dalkıran ◽  
Tahir Hikmet Karakoç

Purpose This study aims to investigate the aviation, energetic, exergetic, environmental, sustainability and exergoeconomic performances of a micro turbojet engine used in unmanned aerial vehicles at four different modes. Design/methodology/approach The engine data were collected from engine test cell. The engine performance calculations were performed for four different operation modes. Findings According to the results, maximum energy and exergy efficiency were acquired as 19.19% and 18.079% at Mode 4. Total cost rate was calculated as 6.757 $/h at Mode-1, which varied to 10.131 $/h at Mode-4. Exergy cost of engine power was observed as 0.249 $/MJ at Mode-1, which decreased to 0.088 $/MJ at Mode-4 after a careful exergoeconomic analysis. Originality/value The novelty of this work is the capability to serve as a guide for similar systems with a detailed approach in the thermodynamic, thermoeconomic and environmental assessments by prioritizing efficiency, fuel consumption and cost formation. This investigation intends to establish a design of the opportunities and benefits that the thermodynamic approach provides to turbojet engine systems.

2018 ◽  
Vol 90 (5) ◽  
pp. 779-787 ◽  
Author(s):  
Emre Kiyak ◽  
Gulay Unal ◽  
Nilgun Fazilet Ozer

Purpose This paper aims to discuss engine health monitoring for unmanned aerial vehicles. It is intended to make consistent predictions about the future status of the engine performance parameters by using their current states. Design/methodology/approach The aim is to minimize risks before they turn into problems. In accordance with these objectives, temporal and financial savings are planned to be achieved by contributing processes such as extending the engine life, preventing early disassembly-reassembly and mechanical wears and reducing the maintenance costs. Based on this point of view, a data-based software is developed in MATLAB (Matrix Laboratory) program for the so-called process. Findings The software is operated for the performance parameters of the turbojet engine that is used in a small unmanned aerial vehicle of Tusas Engine Industry. The obtained results are compared with the real data of the engine. As a result of this comparison, a fault that may occur in the engine can be detected before being determined. Originality/value It is clearly demonstrated that the engine operation in adverse conditions can be prevented. This situation means that the software developed operates successfully.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kahraman Coban ◽  
Selcuk Ekici ◽  
Can Ozgur Colpan ◽  
Tahir Hikmet Karakoç

Purpose This paper aims to investigate the cycle performance of a small size turbojet engine used in unmanned aerial vehicles at 0–5,000 m altitude and 0–0.8 Mach flight speeds with real component maps. Design/methodology/approach The engine performance calculations were performed for both on-design and off-design conditions through an in-house code generated for simulating the performance of turbojet engines at different flight regimes. These calculations rely on input parameters in which fuel composition are obtained through laboratory elemental analysis. Findings Exemplarily, according to comparative results between in-house developed performance code and commercially available software, there is 0.25% of the difference in thrust value at on-design conditions. Practical implications Once the on-design performance parameters and fluid properties were determined, the off-design operation calculations were performed based on the compressor and turbine maps and scaling methodology. This method enables predicting component maps and fitting them to real conditions. Originality/value A method to be used easily by researchers on turbojet engine performance calculations which best fits to real conditions.


2020 ◽  
Vol 14 (1) ◽  
pp. 108-125 ◽  
Author(s):  
Salman Haider ◽  
Javed Ahmad Bhat

Purpose Because of growing energy consumption and increasing absolute CO2 emissions, the recent calibrations about the environmental sustainability across the globe have mandated to achieve the minimal energy consumption through employing energy-efficient technology. This study aims to estimate linkage between simple measure of energy efficiency indicator that is reciprocal of energy intensity and total factor productivity (TFP) in case of Indian paper industry for 21 major states. In addition, the study incorporates the other control variables like labour productivity, capital utilization and structure of paper industry to scrutinize their likely impact on energy efficiency performance of the industry. Design/methodology/approach To derive the plausible estimates of TFP, the study applies the much celebrated Levinsohn and Petrin (2003) methodology. Using the regional level data for the period 2001-2013, the study employs instrumental variable-generalized method of moments (GMM-IV) technique to examine the nature of relationship among the variables involved in the analysis. Findings An elementary examination of energy intensity shows that not all states are equally energy intensive. States like Goa, Rajasthan, Jharkhand and Tamil Nadu are less energy intensive, whereas Uttar Pradesh, Kerala, Chhattisgarh, Assam and Punjab are most energy-intensive states on the basis of their state averages over the whole study period. The results estimated through GMM-IV show that increasing level of TFP is associated with lower level of energy per unit of output. Along this better skills and capacity utilization are also found to have positive impact on energy efficiency performance of industry. However, the potential heterogeneity within the structure of industry itself is found responsible for its higher energy intensity. Practical implications States should ensure and undertake substantial investment projects in the research and development of energy-efficient technology and that targeted allocations could be reinforced for more fruitful results. Factors aiming at improving the labour productivity should be given extra emphasis together with capital deepening and widening, needed for energy conservation and environmental sustainability. Given the dependence of structure of paper industry on the multitude of factors like regional inequality, economic growth, industrial structure and the resource endowment together with the issues of fragmented sizes, poor infrastructure and availability and affordability of raw materials etc., states should actively promote the coordination and cooperation among themselves to reap the benefits of technological advancements through technological spill overs. In addition, owing to their respective state autonomies, state governments should set their own energy saving targets by taking into account the respective potentials and opportunities for the different industries. Despite the requirement of energy-efficient innovations, however, the cons of technological advancements and the legal frameworks on the employment structure and distributional status should be taken care of before their adoption and execution. Originality/value To the best of our knowledge, this is the first study that empirically examines the linkage between energy efficiency and TFP in case of Indian paper industry. The application of improved methods like Levinsohn and Petrin (2003) to derive the TFP measure and the use of GMM-IV to account for potential econometric problems like that of endogeneity will again add to the novelty of study.


2018 ◽  
Vol 18 (1) ◽  
pp. 20-42 ◽  
Author(s):  
Amal Abuzeinab ◽  
Mohammed Arif ◽  
Mohd. Asim Qadri ◽  
Dennis Kulonda

Purpose Green business models (GBMs) in the construction sector represent the logic of green value creation and capture. Hence, the call to examine GBMs is growing ever louder. The aim of this paper is to identify benefits of GBMs by adopting five essential elements of the GBM from the literature: green value proposition; target group; key activities; key resources (KR); and financial logic. Design/methodology/approach In all, 19 semi-structured interviews are conducted with construction sector practitioners and academics in the UK. Thematic analysis is used to obtain benefits of GBMs. Further, the interpretive ranking process (IRP) is used to examine which elements of the GBM have a dominant role in providing benefits to construction businesses. Findings The benefits are grouped into three themes: credibility/reputation benefits; financial benefits; and long-term viability benefits. The IRP model shows that the element of KR is the most important when evaluated against these three benefit themes. Practical implications Linking GBM elements and benefits will help companies in the construction sector to analyse the business case of embracing environmental sustainability. Originality/value This research is one of the few empirical academic works investigating the benefits of GBMs in the construction sector. The IRP method is a novel contribution to GBMs and construction research.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gamze Orhan

Purpose Deregulation of domestic markets and the liberalization of international markets have dramatically changed air transportation. One of the important results of this change is the environmental effects of air transportation. This study aims to examine the implications of air transportation on environmental sustainability in the context of airline business strategies in liberalized and globalized air transport industry. Design/methodology/approach The paper discusses the relationship between liberalization, airline strategies and environmental sustainability of air transportation using the related literature. Then, to show some environmental impacts on the axis of the relationship discussed, emission rates for the aircraft landing and take-off phase were calculated on a global basis based on the aircraft traffic. Findings The discussion in the paper shows that the liberalization policies and the strategies of airlines supported by these policies, in essence, contradict the environmental sustainability of air transport. Considering the flight share projections of EUROCONTROL for different aircraft types on a global basis and the World Bank’s global flight traffic forecast for the years 2016 and 2025, it has been demonstrated that the number of aircraft departures will increase by 30%, whilst the number of aircraft emissions will increase by 41.5%. Practical implications Airlines are one of the main actors that will play a role in reducing the environmental impacts of air transportation. Therefore, this study is important in giving an idea to both policymakers and airline managers on how airline companies’ strategies should be shaped to realize both corporate sustainability and environmentally sustainable air transportation. Originality/value There are many studies in the literature regarding the environmental effects of air transport. However, there are not many studies linking environmental impacts with airline strategies that directly affect air transport demand. This study is different in that it gives environmental sustainability by associating it with its root causes.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Francisco Rincon-Roldan ◽  
Alvaro Lopez-Cabrales

PurposeThe aim of this study was to analyse the influence of different employment relationships (ERs) on the sustainability results of cooperatives. The authors approached the type of ER comparing the inducements offered by the firm with the contributions that the manager expects from employees. In this way, the authors study how the orientation toward the employment relationship influences the economic, social and environmental sustainability of the firm.Design/methodology/approachThis article presents a theoretical and empirical research model about the relationship between ERs and sustainability. The necessary information was obtained through a questionnaire that was completed by the human resource (HR) managers and chief executive officers (CEOs) of 124 cooperative companies, and structural equation modelling was applied to evaluate the relationships between the proposed constructs, using the partial least squares technique (PLS-SEM).FindingsThe obtained results suggest that mutual investment and overinvestment ERs favour economic, social and environmental sustainability, whereas quasi spot contract and underinvestment ERs have a negative influence on all three types of sustainability. Therefore, it is confirmed that the type of ER adopted can condition the sustainability of the company, either favouring or worsening it.Originality/valueThis work contributes to covering the lack of studies about which ERs impact the sustainability of organisations, and it provides information on the role of ERs in the search for a more sustainable organisation, demonstrating that the type of employment relationship developed by the firm has a relevant impact on its sustainability.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Pat Auger ◽  
Timothy M. Devinney ◽  
Grahame Dowling

PurposeOne of the hallmarks of strategizing is having a clearly articulated vision and mission for the organization. It has been suggested that this provides a compass bearing for the organization's strategy, helps in motivation, commitment and retention of employees, serves as a guide to internal sensemaking and decision-making, has a potential performance effect, helps establish the identity of the organization and positions its desired reputation. The compass bearing role is important because it guides the selection of the goals and strategic orientation of the organization which in turn shapes its overall strategy and much of its internal decision making. The inspirational role is important because it helps to motivate and engage employees and other stakeholders.Design/methodology/approachThis study provides a more rigorous indication as to whether employees can, in the first instance, recognize and distinguish their corporate and environmental strategy from that of their competitors within their own industry and random other companies from other industries. This first issue addresses, to a degree, if and why, such strategic communiqués are effective inside a range of different organizations. Secondly, the authors examine whether there are any specific individual level effects that could explain variations in these responses. Finally, the authors examine the extent to which the recognition rates the authors observe, relate to how employees are rewarded through appraisals, promotions and salary increases. This helps in the authors’ understanding of the role of hard incentives versus soft motivations. The authors’ approach to assessing employee knowledge of their organization's strategy is unique. Rather than survey employees about their knowledge, the authors use a matching study and a discrete choice measurement model to assess if they can recognize their organization's strategy from those of their competitors and some other randomly selected organizations. This approach allows us to mitigate social desirability and common method biases and directly estimate the underlying behavioral model being used to assess their organization's strategy.FindingsOverall, the authors found that few employees could correctly identify their corporate strategy statements. In the case of corporate strategy statements, the authors find that, on average, only 29 percent of employees could correctly match their company to its publicly espoused corporate strategy. When the authors look at the environmental sustainability strategy of the firm, this is worse overall, with individuals doing no better than random on average. When the authors look at company training and communication practices across the realm of different strategies, the authors see a number of factors leading to the general results. First, most of the authors’ respondents could not recall a significant effort being given to communication and training by their employer. Indeed, most communication/training is simply related to having documentation/brochures available. Second, respondents indicated that more effort is put into communicating corporate strategy to employees in a more systematic manner than communication about environmental/corporate social responsible (CSR) strategy. Third, the authors see that individuals are evaluated more on and give more weight to, evaluations relating to their ability to meet individual/group financial and market performance metrics (targets) and work as a team than their involvement in environmental and social responsibility programs. Finally, the employees studied seemed to be more confident in understanding the corporate strategy. When asked to put their corporate strategy into words – a task the authors asked respondents to do after the matching phase of the study – 40% of participants did so for the corporate strategy but only 14% did so for the environmental strategy and seven percent for the CSR strategy.Practical implicationsThe primary implication of the study is that the values-mission-strategy logic of strategic motivation seems to have limited validity and with respect to the view that employees are a vector of corporate strategy. It is hard to argue that employees can be a vector for something they cannot recall or even distinguish between.Originality/valueThe study is unique in terms of (1) asking the very simple question of whether employees internalize their company's strategies and (2) in the methodological approach to examine employee knowledge and informativeness.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mehmet Pekkaya ◽  
Nuh Keleş

PurposeConsidering the contribution of freight villages (FVs) to the economy and sector, transportation cost advantage, environmental externalities, labor costs, employment, etc. criteria evaluation is important in selecting FV location. Environmental sustainability and social dimensions are becoming important criteria for companies in logistics. The purpose of the study is to determine/model the criteria interaction and also determine the criteria priorities in the FV location selection process. Meanwhile, the study aims to evaluate these criteria and present information to researchers and decision makers.Design/methodology/approachSix main criteria and 29 sub-criteria are selected from related literature. Decision making trial and evaluation laboratory (DEMATEL) method is used for determining/modeling the criteria interaction and sketching interaction diagram, and the Analytical Hierarchy Process (AHP) method is used for determining the criteria priorities. One/two-way pairwise compared main/sub-criteria views are obtained from 48 experts for calculations.Findings“Trade potential”, “transportation networks” and “economic factors” have the highest priorities, respectively, out of six main criteria, and they have the most powerful interactions that put these criteria to the center of decision process. Sub-criteria of “foreign trade potential”, “proximity to the port”, “market opportunities” and “proximity to the railway” out of 29 have a total 36.42% priority, more than one-third of the importance.Originality/valueCriteria are evaluated in FV location selection for FV sustainability using criteria interaction diagrams, affecting/being affected by the level of each criterion and their priorities. This study shows a hybrid derivation from DEMATEL-AHP usage methods together. High-volumed and qualified/experienced expert group judgments in Turkey are evaluated.


Author(s):  
Mohammad Javad Bazregari ◽  
Mahdi Gholinejad ◽  
Yashar Peydayesh ◽  
Nima Norouzi ◽  
Maryam Fani

This research presents a system to use natural gas to meet electricity, freshwater and cooling needs for a residential building in Bandar Abbas. The system includes a gas turbine, absorption chiller and multi-effect desalination (MED) plant. The energy produced in the gas turbine is used to generate electricity, and the excess energy is used to produce cooling and freshwater. Finally, an exergoeconomic evaluation of the system is performed. The effects of ambient temperature on the output power as well as the exergy current have been investigated. The COP of the absorption cycle has been investigated, and the results show that at an operating temperature of 150∘C compared to 90∘C, the efficiency rate increases to 20%. The highest exergoeconomic cost rate is related to absorption chiller, and the lowest is related to heat recovery steam generation. The results show that if the ambient temperature increases, the production capacity decreases. Increasing the fuel flow rate increases the power. Evaluation of two different solutions to reduce the ambient temperature and increase the fuel flow shows that increasing the fuel flow is a better solution, considering the exergy cost of the absorption chiller, which is 10 times higher than that of the gas turbine.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Anjan Chamuah ◽  
Rajbeer Singh

Purpose The purpose of the paper is to describe the evolving regulatory structures of the civilian unmanned aerial vehicle (UAV) in India and Japan, not yet fully developed to regulate the deployment of the UAV. India and Japan are at the forefront to overhaul the respective regulatory framework to address issues of accountability, responsibility and risks associated with the deployment of UAV technologies. Design/methodology/approach In-depth interviews are conducted both in Japan and India to gather primary data based on the snowball sampling method. The paper addresses questions such as what is the current scenario of civilian UAV deployment in India and Japan. What are the regulation structures for Civil UAV deployment and operation and how they differ in India and Japan? What are the key regulatory challenges for Civil UAV deployment in India? How regulation structure enables or inhibits the users and operators of Civil UAVs in India? What are mutual learnings concerning UAV regulations? Findings Findings reveal that the Indian regulations address issues of responsibility by imparting values of privacy, safety, autonomy and security; Japanese regulation prefers values of trust, responsibility, safety and ownership with more freedom to experiment. Originality/value The study on civilian UAV regulatory framework is a new and innovative work embedded by the dimensions of responsibility and accountability from a responsible innovation perspective. The work is a new contribution to innovation literature looked at from regulatory structures. Field visits to both Japan and India enrich the study to a new elevation.


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