Econometric modeling of cost per flying hour of civil helicopters

2021 ◽  
Vol 20 (11) ◽  
pp. 2168-2186
Author(s):  
Aleksandr S. MAL'TSEV

Subject. The article addresses factors of the growing cost of flying hour, which is an integral indicator of helicopter efficiency at the stage of its operation. Objectives. The purpose is to develop an econometric model of dependence of cost per flying hour on the main relative aircraft performance characteristics that determine the effectiveness of design and technological solutions for civil and multi-purpose helicopters, to make a decision at the preliminary design stage regarding the efficiency of designed product during the operational phase and the feasibility of R&D. Methods. The study rests on basic provisions of the theory of the firm, the theory of fundamental value of assets, international standards of the aviation equipment operation manual. Results. Based on econometric analysis, the main determinants of cost per flight hour are identified from the set of relative flight characteristics of the helicopter. The paper demonstrates that the number of products in operation, the cost of flight hour, the efficiency and transparency of logistics infrastructure in the provision of maintenance services represent a tool for managing the cost of product life cycle during its operation. Conclusions. The main factors having the greatest impact on the efficiency of after-sales service of products in the aviation industry are fuel efficiency, specific fuel consumption (fuel consumption per unit of power). The cost per flight hour is an integral indicator of the effectiveness of after-sales service and depends on relative flight characteristics of aircraft in operation.

2021 ◽  
Vol 13 (14) ◽  
pp. 8066
Author(s):  
Thowayeb H. Hassan ◽  
Abu Elnasr E. Sobaih ◽  
Amany E. Salem

The cost of fuel and its availability are among the most major concerns for aircrafts and the aviation industry overall. Environmental difficulties with chemical pollutant emissions emitted by aviation machines are also connected to fuel consumption. As a result, it is crucial to examine factors that affect the overall fuel usage and consumption in the airport-based aviation industry. Several variables were investigated related to the total fuel consumed, such as dry operating weight (DOW) (KG), zero-fuel weight (ZFW), take-off weight (TOW), air distance (AIR DIST) (KM), and ground distance (GDN DIST). Analysis of the correlation between total fuel consumed as well as the extra fuel and selected variables was conducted. The results showed that the most positively associated factors with the total used fuel were the air distance (r2 = 0.86, p < 0.01), ground distance (r2 = 0.78, p < 0.01), TOW (r2 = 0.68, p < 0.01), and flight time (r2 = 0.68, p < 0.01). There was also a strong positive association between the average fuel flow (FF) and actual TOW (r2 = 0.74, p < 0.01) as well as ZFW (r2 = 0.61, p < 0.01). The generalized linear model (GLM) was utilized to assess the predictions of total energy usage after evaluating important outliers, stability of the homogeneity of variance, and the normalization of the parameter estimation. The results of multiple linear regression revealed that the most significant predictors of the total consumed fuel were the actual ZFW (p < 0.01), actual TOW (p < 0.01), and actual average FF (p < 0.05). The results interestingly confirmed that wind speed has some consequences and effects on arrival fuel usage. The result reflects that thermal and hydrodynamic economies impact on the flying fuel economy. The research has various implications for both scholars and practitioners of aviation industry.


2020 ◽  
Author(s):  
Bruna Carolina Castro Pereira Araújo ◽  
Francisco Miguel Ribeiro Proença Brojo

The aviation industry is increasing leading to a harmful environmental impact. APU is liable for 20% of airport ground-based emissions, 50% of aircraft maintenance costs and more than 5% of the daily fuel consumption [1]. Aware of this growing problem and its consequences, research should be conducted targeting new, non-polluting energy sources capable of meeting or even exceeding the aircraft’s electrical needs. With this in mind, the main goal of this article was to analyze the feasibility of implementing a HT-PEMFC system as a more sustainable alternative for the gas turbine APU in  an Airbus A320. The fuel used was methane which requires a fuel processor to convert it into hydrogen before entering the fuel cell. The maximum output work of this methane-supplied system is estimated at 250 kW. Therefore, a fuel processor and a fuel cell mathematical models were required. The two models along with the thermodynamic analysis were performed in MATLAB. The aims of this project were to evaluate fuel processing of methane and its conversion into electric energy through a fuel cell; to perform the thermodynamic analysis of HT-PEMFC APU based on the first and second laws of thermodynamics; and estimate the total weight, emissions and fuel consumption of the HT- PEMFC APU. The results of this research were  very encouraging, as it shows that the breakeven weight of the HT-PEMFC, for a mass increment of 854 kg, was compensated by a fuel efficiency of ∼2.7 times the conventional APU. Keywords: APU, HT-PEMFC, Fuel cell


Author(s):  
Александр Васильевич Лось

When creating modifications of transport category airplanes, fuel efficiency appears in the structure of their parameters.This indicator is very important, since operating costs largely depend on the amount of fuel consumed per unit of work.The problem of evaluating the fuel efficiency of modifications of transport aircraft with multi-engine power plants is considered. It is noted that multi-engine power plants, used mainly on medium and heavy aircraft, contribute to solving a number of problematic issues:– expanding the ability to operate in hot climates and highlands;– improving operational safety in the event of failure of one or two engines in case of deterioration of take-off/landing conditions, runway conditions, icing conditions and other emergency situations requiring increased thrust-to-weight ratio;– expanding the network of airfields used by reducing the sites of continued or interrupted take-off;– the absence of the need to use on the created modification more powerful engines, domestic or foreign, which do not have forced (emergency) operating modes.– However, the use of forced-mode engines in such power plants leads to a deterioration in fuel efficiency of up to 20 percent.For the preliminary design stage of modifications, a model is proposed for the formation of a fuel efficiency parameter while simultaneously replacing the main engines and changes in the wing geometry, which allows reducing fuel consumption for the flight, and thereby compensating for its losses when using emergency modes.This approach was implemented in the process of development of the An-188 operational tactical military transport aircraft, in which the replacement of 4 theater with 4 turbojet engines was coordinated with the necessary changes in the wing geometry, which allowed the military-technical complex to ensure fuel consumption in horizontal flight mode with maximum payload 154 g/t∙km per unit of useful work, i.e., lower than that of competitors-analogues.


Author(s):  
N.S. Mustafa ◽  
N.H.A. Ngadiman ◽  
M.A. Abas ◽  
M.Y. Noordin

Fuel price crisis has caused people to demand a car that is having a low fuel consumption without compromising the engine performance. Designing a naturally aspirated engine which can enhance engine performance and fuel efficiency requires optimisation processes on air intake system components. Hence, this study intends to carry out the optimisation process on the air intake system and airbox geometry. The parameters that have high influence on the design of an airbox geometry was determined by using AVL Boost software which simulated the automobile engine. The optimisation of the parameters was done by using Design Expert which adopted the Box-Behnken analysis technique. The result that was obtained from the study are optimised diameter of inlet/snorkel, volume of airbox, diameter of throttle body and length of intake runner are 81.07 mm, 1.04 L, 44.63 mm and 425 mm, respectively. By using these parameters values, the maximum engine performance and minimum fuel consumption are 93.3732 Nm and 21.3695×10-4 kg/s, respectively. This study has fully accomplished its aim to determine the significant parameters that influenced the performance of airbox and optimised the parameters so that a high engine performance and fuel efficiency can be produced. The success of this study can contribute to a better design of an airbox.


2021 ◽  
Vol 13 (8) ◽  
pp. 4528
Author(s):  
Olga Lingaitienė ◽  
Juozas Merkevičius ◽  
Vida Davidavičienė

The World Bank, United Nations, the Organization for Economic Cooperation and Development, and others are in line with the governments of countries that are strongly interested in the sustainable development of countries, regions, and enterprises. One of the aspects that affects the indicators and prospects of sustainable development is the efficiency of energy source use. Nationwide reductions in the greenhouse gas emissions of motor vehicles could have a direct effect on ambient temperature and reducing the effects of global warming, which can affect future environmental, societal, and economic development. Significant reductions in fuel consumption can be achieved by increasing the efficiency of use, and the performance, of current cargo vehicles. This aspect is directly related to cargo delivery systems and supply chain efficiency and effectiveness. The article solves the problem of increasing the effectiveness of cargo delivery and proposes a model that would minimize transportation costs that are directly related to fuel consumption, shortening transportation time. The model addresses the problem of a lack of models evaluating the efficiency of cargo to Lithuania that is using several different modes of transportation. For the solution to this problem, the article examines the complexity of the rational use of land and water vehicles depending on the type of cargo transported, the technical capabilities of the vehicles (loading, speed, environmental pollution, fuel consumption, etc.), and the type (cars, railways, ships). The novelty of the findings is based on the availability to select the most appropriate vehicles, on a case-by-case basis, from the available options, depending on their environmental performance and energy efficiency. This model, later in this article, is used for calculations of Lithuanian companies for selecting the most rational vehicle by identifying the most appropriate route, as well as assessing the dynamics of the economic and physical indicators. The model allows for creating dependencies between the main indicators characterizing the transport process—the cost, the time of transport, and the safety, taking into account the dynamics of economic and physical indicators, that lead to a very important issue—reducing the amount of energy required to provide products and services.


2021 ◽  
Vol 1 ◽  
pp. 131-140
Author(s):  
Federica Cappelletti ◽  
Marta Rossi ◽  
Michele Germani ◽  
Mohammad Shadman Hanif

AbstractDe-manufacturing and re-manufacturing are fundamental technical solutions to efficiently recover value from post-use products. Disassembly in one of the most complex activities in de-manufacturing because i) the more manual it is the higher is its cost, ii) disassembly times are variable due to uncertainty of conditions of products reaching their EoL, and iii) because it is necessary to know which components to disassemble to balance the cost of disassembly. The paper proposes a methodology that finds ways of applications: it can be applied at the design stage to detect space for product design improvements, and it also represents a baseline from organizations approaching de-manufacturing for the first time. The methodology consists of four main steps, in which firstly targets components are identified, according to their environmental impact; secondly their disassembly sequence is qualitatively evaluated, and successively it is quantitatively determined via disassembly times, predicting also the status of the component at their End of Life. The aim of the methodology is reached at the fourth phase when alternative, eco-friendlier End of Life strategies are proposed, verified, and chosen.


2021 ◽  
Vol 13 (12) ◽  
pp. 6965
Author(s):  
In-Gyum Kim ◽  
Hye-Min Kim ◽  
Dae-Geun Lee ◽  
Byunghwan Lim ◽  
Hee-Choon Lee

Meteorological information at an arrival airport is one of the primary variables used to determine refueling of discretionary fuel. This study evaluated the economic value of terminal aerodrome forecasts (TAF), which has not been previously quantitatively analyzed in Korea. The analysis data included 374,716 international flights that arrived at Incheon airport during 2017–2019. A cost–loss model was used for the analysis, which is a methodology to evaluate forecast value by considering the cost and loss that users can expect, considering the decision-making result based on forecast utilization. The value was divided in terms of improving fuel efficiency and reducing CO2 emissions. The results of the analysis indicate that the annual average TAF value for Incheon Airport was approximately 2.2 M–20.1 M USD under two hypothetical rules of refueling of discretionary fuel. This value is up to 26.2% higher than the total budget of 16.3 M USD set for the production of aviation meteorological forecasts by the Korea Meteorological Administration (KMA). Further, it is up to 10 times greater than the 2 M USD spent on aviation meteorological information fees collected by the KMA in 2018.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4491
Author(s):  
Changchun Xu ◽  
Haengmuk Cho

Due to the recent global increase in fuel prices, to reduce emissions from ground transportation and improve urban air quality, it is necessary to improve fuel efficiency and reduce emissions. Water, methanol, and a mixture of the two were added at the pre-intercooler position to keep the same charge and cooling of the original rich mixture, reduce BSFC and increase ITE, and promote combustion. The methanol/water mixing volume ratios of different fuel injection strategies were compared to find the best balance between fuel consumption, performance, and emission trends. By simulating the combustion mechanism of methanol, water, and diesel mixed through the Chemkin system, the ignition delay, temperature change, and the generation rate of the hydroxyl group (−OH) in the reaction process were analyzed. Furthermore, the performance and emission of the engine were analyzed in combination with the actual experiment process. This paper studied the application of different concentration ratios of the water–methanol–diesel mixture in engines. Five concentration ratios of water–methanol blending were injected into the engine at different injection ratios at the pre-intercooler position, such as 100% methanol, 90% methanol/10% water, 60% methanol/40% water, 30% methanol/70% water, 100% water was used. With different volume ratios of premixes, the combustion rate and combustion efficiency were affected by droplet extinguishment, flashing, or explosion, resulting in changes in combustion temperature and affecting engine performance and emissions. In this article, the injection carryout at the pre-intercooler position of the intake port indicated thermal efficiency increase and a brake specific fuel consumption rate decrease with the increase of water–methanol concentration, and reduce CO, UHC, and nitrogen oxide emissions. In particular, when 60% methanol and 40% water were added, it was found that the ignition delay was the shortest and the cylinder pressure was the largest, but the heat release rate was indeed the lowest.


Healthcare ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 888
Author(s):  
Leopoldo Sdino ◽  
Andrea Brambilla ◽  
Marta Dell’Ovo ◽  
Benedetta Sdino ◽  
Stefano Capolongo

The need for 24/7 operation, and the increasing requests of high-quality healthcare services contribute to framing healthcare facilities as a complex topic, also due to the changing and challenging environment and huge impact on the community. Due to its complexity, it is difficult to properly estimate the construction cost in a preliminary phase where easy-to-use parameters are often necessary. Therefore, this paper aims to provide an overview of the issue with reference to the Italian context and proposes an estimation framework for analyzing hospital facilities’ construction cost. First, contributions from literature reviews and 14 case studies were analyzed to identify specific cost components. Then, a questionnaire was administered to construction companies and experts in the field to obtain data coming from practical and real cases. The results obtained from all of the contributions are an overview of the construction cost components. Starting from the data collected and analyzed, a preliminary estimation tool is proposed to identify the minimum and maximum variation in the cost when programming the construction of a hospital, starting from the feasibility phase or the early design stage. The framework involves different factors, such as the number of beds, complexity, typology, localization, technology degree and the type of maintenance and management techniques. This study explores the several elements that compose the cost of a hospital facility and highlights future developments including maintenance and management costs during hospital facilities’ lifecycle.


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