First part of the article describes how we can by change of gating system achieve better homogeneity of product made by investment casting. Turbine engine flap was made by investment casting technology – lost wax casting. The casting process was realised in vacuum. The initial conditions (with critical occurrence of porosity) was simulated in ProCAST software. Numerical simulation can clarify during analysis of melt turbulent flow in gate system responsible for creation of entrained oxide films. After initial results and conclusions, the new gating system was created with subsequent turbulence analysis. The new design of gating system support direct flow of metal and a decrease of porosity values in observed areas was achieved. Samples taken from a casting produced with use of newly designed gating system was processed and prepared for metallography. The second part of article deals with identification of structural components in used alloy - Inconel 718. The Ni – base superalloys, which are combined unique physical and mechanical properties, are used in aircraft industry for production of aero engine most stressed parts, as are turbine blades.

The time period of a jet engines full acceleration (from idle run rotating speed to full thrust) is a very important operational parameter. Minimization of this period is an important problem to be solved during the design of the fuel supply and control system. There are many methods of acceleration process control, especially in the case of engines with complicated design configurations. This work presents the problem of acceleration of a simple, single spool turbine jet engine with a so-called stable geometry, in which only one input (control) signal exists - fuel flow rate. Two methods of acceleration control consisting of limitation of the maximum allowable temperature of working medium in front of and behind the turbine in transient states were analyzed. In order to avoid difficulties associated with the direct measurement of actual temperatures, the so-called nonlinear engine observer was applied. With the use of the computer simulation method it was proven that the control algorithm with the limited maximum temperature in front of the turbine makes it possible the shortening of the acceleration time period significantly in comparison with a similar algorithm, that realizes the limitation of temperature behind the turbine.

Results of mathematical modelling and computer simulation of transient processes in the turbine jet engine SO-3 have been presented. The transient processes result from two different fault conditions. In the first case, the transient process has been induced with a rapid fuel shut-off. In the second case, the transient process follows some failure to the shaft that connects the turbine rotor to that of the compressor. The failure occurred in the area of the middle engine bearing support.

The present-day methods of supervising the operational use of jet engines are based, among other things, on computerised procedures of monitoring and recording various failure modes, including the surge. This dangerous mode of operation of a turbojet engine occurs quite commonly while operating it. In some cases, it could result even in the engine destruction. What has been presented in this study is the way of applying a non-linear observer of a one-spool single-flow turbojet to generate a computer algorithm to detect the surging. An exemplary application of such an algorithm to monitor the surging that occurs in the K-15 engine has also been shown.

The effect of processes of accumulating mass and enthalpy of the working medium on the dynamics of transient processes thereof is often discussed in scientific publications on the mathematical modelling of turbine engines (treated as systems that undergo control and automatic adjustment). The paper is intended to make a comparison between findings gained from simulation carried out with two alternative models of an aircraft turbine engine (of the S0-3 type). The first model takes account of the dynamics of the processes of accumulating mass and energy of the working medium within the combustion-chamber volume and that of the convergent nozzle. The second, simplified model, neglects the dynamics of the processes of accumulating mass and energy of the working medium, since it has been assumed that it is the dynamics of the kinetic-energy accumulation in the rotor mass that predominates in various representations of transient processes. To conduct simulation-based experiments, each of the alternative models of an engine was connected to a special simulation unit, which simulated operation of fuel supply and control systems. Two rounds of experiments were carried out. The first one was intended to facilitate observations of transient processes effected with quick shifting of a control lever from the idle position to that of full thrust, and back. In the second round observed were processes resulting from changes in the critical jet area. The second, alternative model was used to investigate the effect of ever-greater hypothetical volumes of the nozzle on how the transient processes proceeded. It has been found that in the case of the S0-3 engine, low nozzle capacity remains of only slight effect on how the transient processes proceed. Hence, simplified modelling methodology is fully justified.

There were done simulations of fuels consumption in the system of electrical energy and heat production based on modernised GTD-350 turbine engine with the use of OGLST programme. In intention the system based on GTD-350 engine could be multifuel system which utilise post-fying vegetable oil, micronised biomass, sludge, RDF and fossil fuels as backup fuels. These fuels have broad spectrum of LHV fuel value from 6 (106 J·kg-1) (e.g. for sludge) to 46 (106 J·kg-1) (for a fuel equivalent with similar LHV as propan) and were simulations scope. Simulation results showed non linear dependence in the form of power function between unitary fuel mass consumption of simulated engine GTD-350 needed to production of 1 kWh electrical energy and LHV fuel value (106 J·kg-1). In this dependence a constant 14.648 found in simulations was multiplied by LHV raised to power –0.875. The R2 determination coefficient between data and determined function was 0.9985. Unitary fuel mass consumption varied from 2.911 (kg·10–3·W–1·h–1) for 6 (106 J·kg-1) LHV to 0.502 (kg·10–3·W–1·h–1) for 46 (106 J·kg-1) LHV. There was assumed 7,000 (h) work time per year and calculated fuels consumption for this time. Results varied from 4,311.19 (103 kg) for a fuel with 6 (106 J·kg-1) LHV to 743.46 (103 kg) for a fuel with 46 (106 J·kg-1) LHV. The system could use fuels mix and could be placed in containers and moved between biomass wastes storages placed in many different places located on rural areas or local communities.

The paper presents a concept of a new turbine engine with the use of rotating isochoric combustion chambers. In contrast to previously analyzed authors’ engine concepts, here rotating combustion chambers were used as a valve timing system. As a result, several practical challenges could be overcome. An effective ceramic sealing system could be applied to the rotating combustion chambers. It can assure full tightness regardless of thermal conditions and related deformations. The segment sealing elements working with ceramic counter-surface can work as self-alignment because of the centrifugal force acting on them. The isochoric combustion process, gas expansion, and moment generation were analyzed using the CFD tool (computational fluid dynamics). The investigated engine concept is characterized by big energy efficiency and simple construction. Finally, further improvements in engine performance are discussed.