Włodzimierz Balicki

Effect of the atmosphere on the performances of aviation turbine engines

Abstract The paper presents how the parameters defining the state of the atmosphere: pressure, temperature, humidity, are affecting performance of the aircraft turbine engines and their durability. Also negative impact of dust pollution level is considered as an important source of engine deterioration. Article highlights limitation of the aircraft takeoff weight (TOW) and requirements for length of the runways depending on weather condition changes. These problems stem from the growing “demand” of gas turbine engines for an air. The highest thrust engines have air mass flow more than 1000 kg/s. Engine inlet ice formation is presented as a result of weather conditions and inlet duct design features.

Safety performance indicators assessment for small aircraft airframe systems

Safety performance indicators are the parameters used for monitoring and assessing safety performance. Such factors are determined based on available safety databases, collected on government level (in Poland Civil Aviation Authority) or by aircraft operators. Aircraft system failure during different flight phases can cause an accident or an incident. Polish Civil Aviation Authority between other data bases manages two important ones called: European Coordination Centre for Aviation Incident Reporting Systems (ECCAIRS) and Aircraft Continuing Airworthiness Monitoring (ACAM).General Aviation (GA) operates mainly aircraft with MTOM<5700 kg powered by the single piston engine. At present, reliability of GA aircraft systems in Poland is unknown. Increasing size of this fleet in Poland requires taking necessary measures in order to establish safety risks and safety performance targets for GA fleet. The authors have performed processing of the data included in available databases analysing airframe failures based on criteria like: phases of flight, ATA chapters concerning aircraft systems and the category of occurrence. The goal of this article is to present method of the current reliability of GA aircraft systems assessment. The results of this analysis can support the decisions of supervisory authorities in the areas where security threats are most important also can help production organizations in identification of the aircraft systems, which required design changes.

Aircraft engines : analysis of reported systems failures in Polish aviation during years 2008-2015

Aircraft engine failure during different aircraft flight phases can cause accidents or incidents. ICAO Annex 19 requires from each state establishing the state safety program (SSP) and from the subordinate aviation organizations safety management system (SMS). Point 5.2.1 of Annex 19 instructs to establish safety database, which should be used for effective analysis of actual and potential safety deficiencies. Such analysis should lead to determining necessary measures in order to improve safety. Polish Civil Aviation Authority among other databases manages an important one called European Coordination Centre for Aviation Incident Reporting Systems (ECCAIRS). The authors have done a laborious processing of the data contained in that database analysing engine failures based on criteria like phases of flight, ATA chapters concerning powerplant and category of the occurrence. Separately, under consideration were taken engines installed on aircraft with an MTOM <5700 kg (mainly General Aviation) and for aircraft with MTOM > 5700 kg (commercial aviation). The article presents a proposed method of predicting the number of events, the alert levels for the next years and for ATA chapters’ determination, assuming a normal distribution (Gaussian). It is one of the first attempts to use the actual data contained in the database of events in Poland. The results of this analysis can support the decisions of supervisory authorities in the areas where security threats are most important.

Development of Gasturbine with Detonation Chamber

Extensive and complex studies of the application of continuously rotating detonation (CRD) to gasturbine are presented. Special installation of high pressure preheated air supply system was constructed which allows to supply air at rate of a few kg/s, preheated to more than 100 °C and at initial pressure up to 2.5 bar. Supply system for Jet-A fuel which could be preheated to 170 °C was also constructed. Additionally gaseous hydrogen supply system was added to the installation. Measuring system for control air flow and measurements of detonation parameters were installed and data acquisition and control system implemented. Extensive research of conditions in which CRD could be established and supported in open flow detonation chambers, throttled chambers and finally in detonation chambers attached to the GTD-350 gasturbine engine where conducted. Conditions for which stable detonation was achieved are presented. It was found that for conditions when the GTD-350 engine was supplied by gaseous hydrogen or by dual-fuel, Jet-A and gaseous hydrogen, thermal efficiency of the engine could be improved even by 5–7% as compared to the efficiency of the base engine.

Report on the implementation of the POIG project „turbine engine with a detonation combustion chamber”

This article contains a description of the work carried out under the UDA-POIG 01.03.01-14-071/09-10 project titled “A turbine engine with a detonation chamber”. The work carried out during the project involved 14 construction, research and calculation tasks. Various research stands designed to analyse the process of mixture formation, initiation of detonation and research of rotating detonation in combustion chambers were constructed. Test stand for examining a turboshaft engine with detonation combustion chamber was built. Those test stands allowed powering the combustion chambers and the engine with both liquid and gaseous fuels, simultaneously or separately. At the same time, REFLOPS software, which could calculate the propagation of a detonation wave was created, and used in the design of further versions of combustion chambers. Data from the experiments was used to verify the calculations and models created in the mentioned software. GTD-350 engine was used as the base; the structure of which (combustion chamber situated outside the turbine-compressor unit) facilitated modifying the shape of the detonation combustion chamber. During the research, great emphasis was placed on the safety of researchers. Working with hydrogen in high temperatures and JET-A1 fuel, which was additionally heated, and the usage of the oxy-acetylene detonators forced extreme caution, and full compliance with developed procedures. The project was divided into 14 tasks that were often conducted simultaneously in a 20-person team implementing the project. The work was completed by performing comparative studies between conventional engine with deflagration combustion chamber, and modified engine with a detonation combustion chamber. During the completion of the project, it was the first working demonstrator engine with detonation combustion chamber in the world.

ASSESSMENT OF THE AIRFRAME SYSTEMS AFFECTING SAFETY RISKS CAUSED BY LARGE AIRCRAFT

Hazard is a safety condition that could cause or be a part of unsafe aircraft operation. It also has an impact on aviation safety related to aircraft systems as well as services. Safety risk is a part of so-called safety management and is the predicted probability and severity of the outcomes of a hazard. Aircraft utilized by airlines and cargo operators which have MTOM >5700 kg are defined by authors as a large aircraft and have to be treated in their systems reliability analysis separately from small aircraft. Despite the fact that both types of aircraft categories events are included in the same databases European Coordination Centre for Aviation Incident Reporting Systems (ECCAIRS) and Aircraft Continuing Airworthiness Monitoring (ACAM), due to different predominant systems failures could not be considered in the same way. The authors have performed processing of the data contained in available databases analysing large aircraft airframe systems faults, which were assigned to the specific ATA chapters. The most frequently occurring defects of the aircraft systems were identified. The goal of this article is to present a method of the current reliability of large aircraft systems assessment. Based on it, the authors are proposing a way of safety risk estimation and prediction of the safety levels for the next two years. The results of this analysis may support the decisions of supervisory authorities in the areas where security threats are most important. They can also help aircraft operators with identification of the aircraft systems, which require special attention.

Balancing Energy Processes in Turbine Engines

Abstract The article discusses the issue of balancing energy processes in turbine engines in operation in aeronautic and marine propulsion systems with the aim to analyse and evaluate basic operating parameters. The first part presents the problem of enormous amounts of energy needed for driving fans and compressors of the largest contemporary turbofan engines commonly used in long-distance aviation. The amounts of the transmitted power and the effect of flow parameters and constructional properties of the engines on their performance and real efficiency are evaluated. The second part of the article, devoted to marine applications of turbine engines, presents the energy balance of the kinetic system of torque transmission from main engine turbines to screw propellers in the combined system of COGAG type. The physical model of energy conversion processes executed in this system is presented, along with the physical model of gasodynamic processes taking place in a separate driving turbine of a reversing engine. These models have made the basis for formulating balance equations, which then were used for analysing static and dynamic properties of the analysed type of propulsion, in particular in the aspect of mechanical loss evaluation in its kinematic system.

SOME PROBLEMS RESULTING FROM POWERING OF TURBINE ENGINES BY LIQUIFIED PETROLEUM GAS (LPG)

There has been observed for several years a number of attempts to introduce for everyday use small power units which utilize turbine engine as propulsion unit (the U.S., Japan, and Europe). Efficiency increase of such devices is achieved by improving of turbine engine design as well as utilizing of exhaust gas thermal energy to heat the compressed air supplied to combustion chamber and, for example to heat usable water. Significant orientation of turbine engine improvements lead to the modernization of combustion processes by applying of gaseous fuels (such as compressed natural gas) or implementation of high-temperature catalytic combustion. The purpose of these changes reduction of hydrocarbons, carbon monoxide and nitrogen oxides emissions. In Propulsion Department of Aviation Institute a scientific project has been realized, in which the object of study was aircraft turbine engine powered by a liquid propane-butane mixture. The paper presents some results of engine tests carried out, especially concerning feeding system, special fuel system applied LPG pumping systems with the use of sliding-vane pump and by means of pressure reservoir and combustion process of LPG atomized with the use of original GTD-350 vortex injector, adapted for aviation kerosene Jet-A.

Aviation : environmental threats

Based on the available information and authors self-assessments, this article presents turbine engine exhaust gases effect on the environment, especially near to the aircraft and helicopters during their engines idle setting and take-offs. The concentration level of pollutants in gas turbine exhaust and its relation to the temperature and time of the combustion process is discussed. The article presents diffusion of the aircraft turbine engine exhaust in the airport area, focusing on aircraft take-off manoeuvre. The authors would like to draw attention of the aviation professionals to the fact that amount of exhaust from the turbine engine is so significant that may adversely change the ambient air near to the aircraft. Consequently, smaller amount of oxygen with increased level of carbon monoxide during engine start –up and idle can be a threat to the maintenance staff health. Also high emission level of the nitrogen oxides, especially during take-off and climb is indifferent for the environment. The paper gives an example of real fuel consumption and toxic gases emissions in the so-called landing and takeoff cycle (LTO) and during long-range flight. Turbine engines noise distribution and its intensity because of complex aerodynamic and thermodynamic processes is presented.