Sources of renewable energy have been increasingly used all over the world. This kind of energy is highly desirable because of its unlimited availability. Unfortunately, renewable energy production very much depends on weather conditions. Consequently, it is necessary to store the produced excess energy in order to use it when needed. There is a technology able to produce a hydrogen/methane fuel from excess renewable energy, which may be stored. This technology is called the Power-to-Gas technology (P2G). Since the efficiency of this technological process depends on the hydrogen fraction in the renewable energy fuel, there is a need to increase this fraction. Concurrently, the gas microturbine technology is increasingly widely used in various industries (aviation, energy, automotive, military, etc). The P2G technology and the gas microturbine technology are likely to be integrated in the near future and, as mentioned above, the hydrogen fraction in the methane-hydrogen fuel will tend to increase. In order to power a gas microturbine with the methane-hydrogen fuel, it will be necessary to modify the combustor to avoid an excessive temperature increase and flashbacks. In this paper it is proposed to apply an autonomous internal exhaust gas recirculation system to resolve the hydrogen combustion problems indicated above. The operating principle and the proposed design of the recirculation system and the latter’s impact on the combustor’s operating parameters and emissivity (NOx and CO) are presented.

The gas microturbines gain significance in various industry sectors. One of their most crucial advantages is the capability of utilizing variety of fuels. At the same time, the emissions regulations become increasingly strict. This is why there is a need to look for a new technological solution to limit the emissions of selected substances, like carbon monoxide (CO) and nitrogen oxides (NOx). The internal recirculation of the flue gases is well known to limit the temperature peak and for the homogenization of the temperature field gradient in different combustion chambers. This paper presents a numerical investigation of a novel internal flue gas recirculation system applied to gas microturbine combustors. The ability to perform an internal exhaust gases recirculation by adding a combustor internal pipe system was verified numerically. This paper exposed the numerical investigation methods and obtained results. The study presents the concept and results performed on three cases of internal exhaust gases recirculation systems applied to a reference combustor. The work permitted to demonstrate numerically that it is possible to perform an autonomous exhaust gases recirculation inside gas microturbine combustor at a maximum global rate of 0.51%, and that the recirculation system has an impact on the combustion processes without specially modifying the combustor work parameters.

Aviation has, over the years, become an inseparable element of human life. Airplanes are very commonly used for various tasks, such as transport of passengers and goods, military attack and defence, rescue, recreation and so on. In spite of the many advantages of aviation, one cannot ignore its disadvantages. The most important disadvantages of aviation are the emissions that cause atmospheric pollution and noise. Additionally, one should remember about the decreasing stocks of non-renewable fuels. These drawbacks affect human health and the natural environment. Therefore, a good alternative to conventional drive units in aircraft may turn out to be electric drive units in the near future. The aim of this article is to check the extent to which today’s knowledge and technology allow the use of electric drive units instead of conventional aircraft drive units. This article presents the concept of electric aircraft, from the electric drive unit to its power supply system. The feasibility of designing an electric jet drive unit for a passenger aircraft was analysed based on the performances of PZL 104 Wilga 35 and Boeing B787 Dreamliner.

Today we live in a diminishing world due to effective ways of transport, especially aviation. One of the most recent and important issues of our life and scientific research has become the negative climate change – partially due to aviation emission. The “More Electrical Aircraft” has been a term recently created. The ideology of this concept is to power onboard aircraft devices by electrical energy as much as possible. Applying new kind of electrical onboard energy sources (excluding these coming from traditional engines), there is a potential possibility to reduce fuel consumption. Such new electrical energy sources need to respond to some criteria, the most important one of which is that the energy density of the new electrical energy source must be as close as possible, or even greater than the energy density of the traditional fuel aircraft, taking into consideration the efficiency of traditional onboard energy generators. The achievement of this criterion makes the applicability of these new electrical energy sources justifiable. Covering the upper part of the aircraft fuselage oriented to solar radiations by flexible photovoltaic modules creates the possibility to obtain a new onboard electrical energy source. The new energy source is characterised by the fact that its energy production depends on the solar exposition time. Taking into account mass of the photovoltaic installation (in this study for B787) and power generated by these modules, the interrupted flight time needed to achieve the energy density criterion, explained above, has been estimated. Taking into account the current technological possibilities and strongly optimised flight conditions, this time is about 29 hours. Commercial aircraft do not exhibit such long flight duration, which makes the application of accessible flexible photovoltaic modules to passenger aircraft unsuitable.