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Tartu, Estonia

Kuut A.,Estonian University of Life Sciences | Ritslaid K.,Estonian Aviation Academy | Olt J.,Estonian University of Life Sciences
Agronomy Research | Year: 2011

In recent years the use of ethanol and mixtures thereof as a fuel in internal combustion engine has been studied at Estonian University of Life Sciences. In the course of the research there have occurred new problems and issues to solve. Ethanol fuels in this study include bioethanol produced in farm environment, hereinafter referred to as farmstead ethanol. Farmstead ethanol is simply bioethanol obtained by applying a simpler (cheaper) production method. Such a production process does not adhere to or comply with the requirements set out for potable spirit. The first part of the article provides an overview of the production and properties of ethanol fuel. The second part contains comparative test results, analysis and conclusion concerning the use of ethanol, farmstead ethanol and gasoline (regular fuel) in Otto motor.

Nommik A.,Estonian Aviation Academy | Nommik A.,Tallinn University of Technology | Kukemelk S.,Nordic Aviation Group | Kukemelk S.,Tallinn University of Technology
Aviation | Year: 2016

the gravity model is a method that is used by transportation researchers, airline network planners and analysts to explain how traffic is distributed between city pairs in correlation to the distance or travelling time between them, which as a result indicates the behaviour of travellers or the performance of the transport connection. How ever, the applicability of the model depends on the reliability of the results, which poses a major issue for researches. The major difficulty is to obtain comparable qualitative insights into the key parameters that are selected. This paper presents a possibility study for the use of the gravity model for regional route planning from the scientific point of view and suggests possibilities of gravity model calibration for airline network analysis including alternative methods for estimating the gravity potential of destinations and measurement of the influence of distance on the potential. The focus of the research is the ability to explain and forecast the development of regional air transportation routes in the commercial aviation network when there is a lack of recorded booking demand data. © 2016 Vilnius Gediminas Technical University (VGTU) Press.

Mrtens K.,Danmark A/S | Umborg J.,Estonian Aviation Academy
Aviation | Year: 2012

This report deals with the project-based learning used by the communication and navigation systems laboratory in teaching aviation engineers. © 2012 Vilnius Gediminas Technical University (VGTU) Press Technika.

Vanker S.,Tallinn University | Enneveer M.,Estonian Aviation Academy | Reppo M.,Tallinn University
18th International Congress on Sound and Vibration 2011, ICSV 2011 | Year: 2011

This paper aims at studying the case of Tallinn Airport in Estonia, with a focus on evaluating the airport noise and its impact on the neighbouring residential districts. Tallinn Airport is located within the city area, and therefore the inhabited areas are also exposed to aviation noise. A peculiarity of air traffic distribution in Tallinn is that only about 18% of take-offs and approaches take place above the city, west of the airport, and 82% above the not densely built-up land east of the airport. As the annual average traffic is relatively sparse in/from western directions, the area exposed to relevant noise input is smaller in the west than in the east. To maintain take-offs and landings from eastern directions as the preferred options is regarded as an appropriate mitigation measure concerning the increasing air traffic. The monitoring system at Tallinn Airport enable operating noise and aircraft noise to be analysed and predicted as a way to differentiate the landing fees for aircraft depending on noise and flight trajectory. By analyzing the survey, conducted in the nearby housing estates of the airport, it turned out that generally the residents do not complain about excessively loud and disturbing noise in their neighborhood.

Lauk P.,Tallinn University of Technology | Lauk P.,Estonian Aviation Academy | Unt K.-E.,Estonian Aviation Academy
Aviation | Year: 2015

The effect of miniflaps for increasing the L/D ratio and the lift coefficient has been studied on airliners as well as on UAV-s and wind turbines. For sailplanes the lift when Cl>1.0 is of main interest. As the maximum wing loading of racing sailplanes reaches 60-62kg/m2, it is necessary to achieve a high Cl max (1.7-1.8) in thermals. In this case the decrease in TAS caused by a high Cl max even compensates for the drop of the L/D ratio to a certain extent, as the climb speed will increase when the spiral flight radius diminishes in thermals. To bring the L/D to Cl>1.0, a 2% chord miniflap at a 30° deflection angle was attached to the trailing edge of a Jantar-Standard 3 type sailplane wing (airfoil NN-8). In flight tests it was found that the miniflap increased the sailplane's Cl max to 1.35-1.66, i.e. by 23% (Re 1.0-0.92×106). At the same time the L/D ratio Cl increased by over 1.0. Especially good L/D improvement was noted with Cl at 1.13-1.19. In thermal Cl of 1.57-1.65 the roll control was good. At lower Cl<1.0 values, the miniflap reduced the L/D ratio in comparison with a normal configuration. © 2015 Vilnius Gediminas Technical University (VGTU) Press.

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