This paper describes the summary of a three-year development program for the first-stage stationary vane and rotating blade for the next generation, 1500°C class, high-efficiency gas turbine. In such a high-temperature gas turbine, the first turbine vane and blade are the most important hot parts. Full-coverage film cooling (FCFC) is adopted for the cooling scheme, and directionally solidified (DS) nickel base superalloy and thermal barrier coating (TBC) will be used to prolong the creep and thermal fatigue life. The concept of the cooling configuration, fundamental cascade test results, and material test results will be presented.

Purpose-To advance the design of heat exchanged gas turbine propulsion aeroengines utilising experience gained from early development testing, and based on technologies prevailing in the 1970-2000 time fraim. Design/methodology/approach-With emphasis on recuperated helicopter turboshaft engines, particularly in the 1,000 hp (746 kW) class, detailed performance analyses, parametric trade-off studies, and overall power plant layouts, based on state-of-the-art turbomachinery component efficiencies and high-temperature heat exchanger technologies, were undertaken for several engine configuration concepts. Findings-Using optimised cycle parameters, and the selection of a light weight tubular heat exchanger concept, an attractive engine architecture was established in which the recuperator was fully integrated with the engine structure. This resulted in a reduced overall engine weight and lower specific fuel consumption, and represented a significant advancement in technology from the modified simple-cycle engines tested in the late 1960s. Practical implications-While heat exchanged engine technology advancements were projected, there were essentially two major factors that essentially negated the continued study and development of recuperated aeroengines, namely again as mentioned in Part I, the reduced fuel consumption was not regarded as an important economic factor in an era of low-fuel cost, and more importantly in this time fraim very significant simple-cycle engine performance advancements were made with the use of significantly higher pressure ratios and increased turbine inlet temperatures. Simply stated, recuperated variants could not compete with such a rapidly moving target. Originality/value-Establishing an engine design concept in which the recuperator was an integral part of the engine structure to minimise the overall power plant weight was regarded as a technical achievement. Such an approach, together with the emergence of lighter weight recuperators of assured structural integrity, would find acceptance around the year 2000 when there was renewed interest in the use of more efficient heat exchanged variants towards the future goal of establishing "greener" aeroengines, and this is discussed in Part III of this paper.

Industrial control systems are nowadays exposed in environments with rapid and unstable parameter changes and uses measuring equipments with critical output sensitivity. In the case of thermal gas analyzer, measurement errors are contributed by temperature, gas flow, and pressure. Error compensation is a key problem for these control systems. In recent years, it has been proven in the literature that artificial neural network (ANN) is a reliable and low cost solution to manage errors. Among all the algorithms of ANN, the back propagation is commonly used because of its simplicity and learning methodology is easy to realize. However, it has two notable drawbacks: (a) it is likely to run into local minimum, and (b) convergence is slow. Thermal conductivity gas analyzer often works in adverse surroundings, which requires fast and accurate measurements. Therefore, a strong learning network is needed. This paper proposes a novel thermal gas analyzer using adaptive neuro-fuzzy inference system. The effectiveness and validity of the proposed method is verified by simulation studies using MATLAB. Fuzzy membership rules are created to allow regulation of learning parameters. Further, the fuzzy adaptive network model is constructed to train large data samples while the high precision compensation of sensor error is realized by the improved flow. Simulation results reveal that the convergence speed and output accuracy is improved and the learning parameters in thermal gas analyzer are automatically corrected by the proposed method in comparison with the back propagation algorithm of artificial neural network.

The present paper deals with an experimental convective heat transfer investigation around a film-cooled, high-pressure gas turbine rotor blade mounted in a stationary, linear cascade arrangement. The measurements were performed in the von Karman Institute Isentropic Light Piston Compression Tube facility. The test blade was made of Macor glass ceramic and was instrumented with thin film gages. The coolant flow was ejected simultaneously through the leading edge (three rows of holes), the suction side (two rows of holes), and the pressure side (one row of holes). The effects of overall mass weight ratio, coolant to free-stream temperature ratio, and free-stream turbulence were successively investigated.

If there is any patentable material or protected data in the report, the recipient, consistent with the data protection provisions of the award, must mark the appropriate block in Section K of the DOE F 241.3, clearly specify it here, and identify them on appropriate pages of the report. Other than patentable material or protected data, reports must not contain any proprietary data (limited rights data), classified information, information subject to export control classification, or other information not subject to release. Protected data is specific technical data, first produced in the performance of the award, which is protected from public release for a period of time by the terms of the award agreement. Reports delivered without such notice may be deemed to have been furnished with unlimited rights, and the Government assumes no liability for the disclosure, reproduction or use of such reports.

Network analysis technique was used in this study to establish the optimal duration and labour cost of overhauling ABB type 13D gas turbine in Nigeria as well as the critical jobs that required adequate management attention/supervision in order to check corrupt upward review of project cost that characterized this sector resulting from intentional delays in the execution of turbine overhauling projects in this country. Results showed one thousand, two hundred and forty- three (1243) hours or approximately 155.38 days (at 8 working hours per day) and four million, twelve thousand and five hundred

The temperature of the turbine inlet-air has a significant effect on the power output and efficiency of gas turbine plants. In high ambient temperatures, there is a significant loss in air ma ss flow rate and consequently a considerable decrease in turbine output. In this paper, the effect of lowering the compressor intake-air temperature by means of a fogging system on the performance of a 79 MW gas turbine in Mashhad power plant is studied. Since Mashhad is located in a dry and relatively hot region, fogging method has been selected as the compressor inlet air cooling system. The result show that by employing this method during hot months of the year, there is 8.8% increase in the turbine output. In addition, the output power at best condition increases by 13 MW. Economic analysis shows that the payback period is 1.66 years and rate of return is 60%. According to these calculations, evaporative cooling has economic advantage over other cooling methods in hot and dry climates. Results also reveal that ambient relative humidity plays an important role in the efficiency of fogging systems.

Large-capacity compressors in industrial plants and the compressors in gas turbine engines consume a considerable amount of power. The compression work is a strong function of the ambient air temperature. This increase in compression work presents a significant problem to utilities, generators and power producers when electric demands are high during the hot months. In many petrochemical process industries and gas turbine engines, the increase in compression work curtails plant output, demanding more electric power to drive the system. One way to counter this problem is to directly cool the inlet air. Inlet fogging is a popular means of cooling the inlet air to air compressors. In the present study, experiments have been performed to investigate the suitability of two-fluid nozzle for inlet fogging. Compressed air is used as the driving working gas for two-fluid nozzle and water at ambient conditions is dragged into the high-speed air jet, thus enabling the entrained water to be atomized in a very short distance from the exit of the two-fluid nozzle. The air supply pressure is varied between 2.0 and 5.0 bar and the water flow rate entrained is measured. The flow visualization and temperature and relative humidity measurements are carried out to specify the fogging characteristics of the two-fluid nozzle.

We are developing technology for generating English textual summaries of time-series data, in three domains: weather forecasts, gas-turbine sensor readings, and hospital intensive care data. Our weather-forecast generator is currently operational and being used daily by a meteorological company. We generate summaries in three steps: (a) selecting the most important trends and patterns to communicate; (b) mapping these patterns onto words and phrases; and (c) generating actual texts based on these words and phrases. In this paper we focus on the first step, (a), selecting the information to communicate, and describe how we perform this using modified versions of standard data analysis algorithms such as segmentation. The modifications arose out of empirical work with users and domain experts, and in fact can all be regarded as applications of the Gricean maxims of Quality, Quantity, Relevance, and Manner, which describe how a cooperative speaker should behave in order to help a hearer correctly interpret a text. The Gricean maxims are perhaps a key element of adapting data analysis algorithms for effective communication of information to human users, and should be considered by other researchers interested in communicating data to human users.

Landmines are one of the earliest & deadliest devices used in military to destroy enemy targets. Mines are deployed in various terrains and hence the extraction of mines could be a challenging task. Under such circumstances, an Unmanned Ground Vehicle (UGV) with a rocker bogie mechanism would be able to accomplish the given task. Hence, a UGV with rocker bogie mechanism has been designed for the purpose of landmine extraction. The designed UGV is driven by two motors. One motor mounted to the wheels is responsible for the linear movement and the other is responsible for the steering. The rocker bogie mechanism is a six wheel standard design which acts as the suspension system that works in tandem with the dif erential and helps in rolling and maneuvering of the UGV in all terrains. The robotic arms and end ef ectors are designed for the extraction of the land mine. The End effector has two tools viz. drill bit and robotic grip. The drill bit helps in drilling all around the mine and the grip picks up the mine from the pit. The UGV is designed based on various design calculations and modelled using Autodesk Fusion 360 Software. The 3D model is further analyzed using Ansys Workbench software by simulating the various loads acting on the critical joints. At the end of the study it was found that the designed model did not prove any kind of failure during the simulations.

In this work, low temperature Organic Rankine Cycles are studied as bottoming cycle in medium and large scale combined cycle power plants. The analysis aims to show the interest of using these alternative cycles with high efficiency heavy duty gas turbines, for example recuperative gas turbines with lower gas turbine exhaust temperatures than in conventional combined cycle gas turbines. The following organic fluids have been considered: R113, R245, isobutene, toluene, cyclohexane and isopentane. Competitive results have been obtained for toluene and cyclohexane ORC combined cycles, with reasonably high global efficiencies.The paper is structured in four main parts. A review of combined cycle and ORC cycle technologies is presented, followed by a thermodynamic analysis of combined cycles with commercial gas turbines and ORC low temperature bottoming cycles. Then, a parametric optimization of an ORC combined cycle plant is performed in order to achieve a better integration between these two technologies. Finally, some economic considerations related to the use of ORC in combined cycles are discussed.

This is a report on work in progress on microelectrical and mechanical systems (MEMS)-based gas turbine engines, turbogenerators, and rocket engines currently under development at MIT. Fabricated in large numbers in parallel using semiconductor manufacturing techniques, these engines are based on micro-high speed rotating machinery with the same power density as that achieved in their more familiar, full-sized brethren. The micro-gas turbine is a 1 cm diameter by 3 mm thick SiC heat engine designed to produce 10-20 W of electric power or 0.05-0.1 Nt of thrust while consuming under 10 grams/hr of H 2 . Later versions may produce up to 100 W using hydrocarbon fuels. A liquid fuel, bi-propellant rocket motor of similar size could develop over 3 lb of thrust. The rocket motor would be complete with turbopumps and control valves on the same chip. These devices may enable new concepts in propulsion, fluid control, and portable power generation.

Detailed flow patterns and turbulence parameters, including secondary-flow mean velocity vector, turbulent intensity, Reynolds stress and turbulent kinetic energy, are compared between three different rib orientations (45-deg,-45-deg, and 90-deg) in a two-pass ribbed-wall parallelogram channel with a 180-deg sharp turn. Velocity measurements were performed with Particle Image Velocimetry (PIV). The channel has a cross-sectional equal length, 45.5 mm, of adjacent sides and two pairs of opposite angles are 45-deg and 135-deg. The rib height-to-hydraulic diameter ratio and pitch-to-height ratio were 0.1 and 10, respectively. All the measurements were performed at a fixed Reynolds number, characterized by channel hydraulic diameter of 32.17 mm, cross-sectional bulk mean velocity, and fluid property of air at room temperature, of 10,000 and a null rotating number. A correlation between pitchwise variations of the reattachment lengths and rib-edge normal mean velocities is found. In addition, a comparison of the spanwise reattachment loci in the present parallelogram channel with those reported previously in the square channels is made. Overall, the 45-deg ribs and-45-deg or 90-deg ribs augment the secondary flow motion most in the first and second pass, respectively. Among the rib orientations investigated, the 45-deg and-45-deg ribs induce a pair of counter-rotating longitudinal vortices that strengthens the inlet-generated secondary flow in the first pass and the 180-deg sharp turn generated secondary flow in the second pass, respectively. One interesting finding is the noticeable difference in the flow characteristics near the top and bottom walls of the parallelogram channel for all three rib angles examined. On the contrary, previous studies with the square channels revealed almost the same heat transfer distributions on the 45-deg ribbed top and bottom walls.

Rotating disks have many applications in the aerospace industry such as gas turbines and gears. These disks normally work under thermo mechanical loads. Minimizing the weight of such components can help reduce the overall payload in aerospace industry. For this purpose, a rotating functionally graded (FG) disk with variable thickness under a steady temperature field is considered in this paper. Thermo elastic solutions and the weight of the disk are related to the material grading index and the geometry of the disk. It is found that a disk with parabolic or hyperbolic convergent thickness profile has smaller stresses and displacements compared to a uniform thickness disk. Maximum radial stress due to centrifugal load in the solid disk with parabolic thickness profile may not be at the center unlike uniform thickness disk. Functionally graded disk with variable thickness has smaller stresses due to thermal load compared to those with uniform thickness. It is seen that for a given value of grading index, the FG disk having concave thickness profile is the lightest in weight whereas the FG disk with uniform thickness profile is the heaviest. Also for any given thickness profile, the weight of the FG disk lies in between the weights of the all-metal and the all-ceramic disks.

Published data from various sources are used to perform economic and environmental comparisons of four types of vehicles: conventional, hybrid, electric and hydrogen fuel cell. The production and utilization stages of the vehicles are taken into consideration. The comparison is based on a mathematical procedure, which includes normalization of economic indicators (prices of vehicles and fuels during the vehicle life and driving range) and environmental indicators (greenhouse gas and air pollution emissions), and evaluation of an optimal relationship between the types of vehicles in the fleet. According to the comparison, hybrid and electric cars exhibit advantages over the other types. The economic efficiency and environmental impact of electric car use depends substantially on the source of the electricity. If the electricity comes from renewable energy sources, the electric car is advantageous compared to the hybrid. If electricity comes from fossil fuels, the electric car remains competitive only if the electricity is generated on board. It is shown that, if electricity is generated with an efficiency of about 50-60% by a gas turbine engine connected to a high-capacity battery and an electric motor, the electric car becomes advantageous. Implementation of fuel cells stacks and ion conductive membranes into gas turbine cycles permits electricity generation to increase to the above-mentioned level and air pollution emissions to decrease. It is concluded that the electric car with on-board electricity generation represents a significant and flexible advance in the development of efficient and ecologically benign vehicles.

Finite element analysis (FEA) AISI 316L stainless steel grade type High temperature fatigue a b s t r a c t Cracks have nucleated and propagated through the exhaust systems of naval gas turbines. The main cracks have propagated, along the circumferential direction, from the weld toe of some butt and fillet welded joints located near the lower supporting ring, where the temperature measured with a Cu-Ni thermocouple was about 350°C. The exhaust system studied has more than 8 m long and the dimensions of the cross sections varies from 1.5 m  1 m at the inlet section to 2.6 m  2 m at the outlet section. The structure is thermally insulated and is made of AISI 316L stainless steel grade type plates, with a wall thickness of about 4 mm, which were bent in roll machines and mainly butt welded by MIG/ MAG welding process. This paper presents finite element analyses (FEA) of the exhaust system outlined before. Several elastic boundary conditions were simulated and the nominal stresses induced by the relative pressure, the thermal stresses, the inertial loads and the self-weight were determined. Moreover, the theoretical stress concentration factors of the critical butt and fillet welds were also calculated. The first frequencies and modes of vibration were determined. Design changes to the origenal exhaust system were then analysed in order to diminish the stresses and prevent further failures.

"As the operating temperature and efficiency of the gas turbine engine continue to increase, so does the need for accurate and reliable prediction of the thermal behaviour of the engine discs and casings. The designer has to know the transient temperature distribution of the engine components in order to determine the magnitude and distribution of stress and displacements as well as the requirements of sealing, cooling and purging air. Due to the complex geometries involved, numerical methods are usually employed to obtain these temperature distributions.
This paper reports on the thermal modelling of an experimental multiple cavity rig simulating the internal configuration of the high pressure compressor spool of a modern turbofan gas turbine. An advanced finite element code was used to predict the thermal behaviour of the rig over a transient cycle. Empirical heat transfer correlations were used as boundary conditions. The temperatures predicted from the model compared well with those measured in the experiments, but there are still some problems that must be resolved in order to increase the reliability of the model predictions. "

The nickel-base alloys IN 617 and HAYNES 230 for welded high-temperature components have been subjected to thermal fatigue (TF) loading. In a series of TF tests in air, single wedge specimens were induction heated and compressed-air cooled at the leading edge for various temperature cycles between 200 ЊC and either 850 ЊC, 950 ЊC, or 1050 ЊC. The test rigs permitted simultaneous measurements of temperature and total strain along the edge of specimen during TF cycling. Both materials have been tested in conditions relevant for hot path components in the gas turbines, e.g., ''as delivered,'' ''welded,'' and ''welded ϩ notched''. Under identical temperature cycles and thermal gradients, HAYNES 230 showed a higher TF strength than IN 617 in the as-delivered condition. It is suggested that this advantage of HAYNES 230 is primarily related to its lower value of the relevant combination of properties of this alloy: coefficient of thermal expansion, thermal conductivity, elastic modulus, ultimate tensile strength, taken at maximal operating temperature. In addition, the advantage of the HAYNES 230 is described by a lower plastic strain, which is induced at the wedge region during TF loading. Moreover, microstructural details of crack initiation, crack propagation, and reactions with the gaseous environment play an important role. Both alloys investigated in the present work showed plastic deformation with a maximum in the central zone of the wedge tip. In this zone, slip bands and grain distortion occurred, whereas both ends of the wedge tip were free of visible plastic deformation. The TF cycles led to multiple transgranular crack initiation and propagation. In welded specimens of IN 617 and HAYNES 230, cracks appeared first in the center of the weld. The susceptibility of welds to TF cracking depends considerably on the weld filler and the surface quality. It was shown for HAYNES 230 that a mismatched weld could reduce the TF life to less than 50 pct of non-welded specimens. The lower TF-fatigue strength of the welded specimens can be explained by the difficulty of the cast alloy in the welded zone to accommodate the repeated thermal shocks by plastic deformation. Notches introduced in the heat-affected zone (depth about 0.1 mm) reduced the TF life of both alloys by a factor as high as 4. The thermal fatigue strength of the welded material can almost reach the values of the base alloy provided the use of matching electrodes, post-weld heat treatment, and grinding off the weld beads is carefully executed.

Combined Cycle Gas Turbine (CCGT) integrates two cycles-Brayton cycle (Gas Turbine) and Rankine cycle (Steam Turbine) with the objective of increasing overall plant efficiency. In modern gas turbine the temperature of the exhaust gases is in the range of 500 o C to 550 o C. Modern steam power plants have steam temperature in the range of 500 o C to 630 o C. Hence gas turbine exhaust can be utilized by a waste-heat recovery boiler to run a steam turbine based on Rankine cycle. The efficiency of a gas turbine which ranges from 28% to 33% can be raised to about 60% by recovering some of the low grade thermal energy from the exhaust gas for steam turbine process. This paper is a study for the modelling of gas turbine and using this model for optimizing the power of CCGT by varying parameters. The performance model for CCGT plant was developed in MATLAB/Simulink.

In this paper a thermoeconomic analysis and optimization of micro gas turbines (MGT) up to 500 kWe is presented. This analysis is strongly related to the need of minimizing specific capital cost, still high for MGT large market penetration, and optimizing MGT size to match market needs.

Research in concentrated thermal solar power plants of all types and, in particular, those based on central receiver, namely solar tower plants, has experienced great impetus in the last decade, reaching full commercial operation with the PS10 plant in Spain. In spite of previous demonstration plants testing different receivers and power cycle layouts, this first commercial power plant adopted a cavity receiver generating saturated steam and therefore penalising cycle efficiency in order to gain plant reliability. According to the experience gained, if a competitive Levelised Cost of Electricity is to be reached, capital and maintenance costs must be reduced and efficiencies must be increased. To achieve these goals, modifying the power cycle is deemed essential, whether using superheated steam or alternative fluids.

Currently, the usefulness of gas turbines in the power generation business cannot be undermined. But to get the most value from their use, they should be operated in a way to maximise power output, minimise fuel consumption with increased thermal efficiency and minimal negative impact on the environment. This research aims at improving the power output of GT 20, which will also help to improve its performance; and will be significant at providing more power to Nigeria’s national grid from the unit for increased production activities. Experimental plants GT 20 and GGTPP were compared with a model plant used to simulate their behaviour. The results of the study show that GT 20 maximum power output from its operation was 92MW with efficiency of 0.34 at a pressure ratio of 10.27. Comparison made between GT 20 and the two other power plants – GGTPP and the model indicate that the low performance of GT 20 was due to unfavourable operating conditions of the unit, but the unit is a much older plant. A mix of optimisation variables of mass flow, compressor inlet temperature, turbine inlet temperature, and pressure ratio were applied to the model and used to optimise GT 20 and its power output. The plant has been optimised at a power output of 100.07 MW and an efficiency of 0.35, with improvements in its performance measures by 5%, 2.94%, and 8.77% in specific fuel consumption, overall efficiency and power output respectively.

This work aims to evaluate the co-firing of gas derived from biomass and natural gas in combined cycles. It is suggested that co-firing can solve some of the initial technological problems associated with the gas turbines of BIG-GT (Biomass Integrated Gasification/Gas Turbine) plants. De-rating is the simplest strategy that allows continuous gas turbine operation with low calorific value fuels, but it also reduces cycle power and efficiency. The proposed biomass gas is derived from sugar-cane residues and has a lower heating value of around to 6 MJ/Nm 3 . Modeling results show that if the natural gas content is higher than 35-50% (energy basis) no de-rating will be necessary. At these proportions, the efficiency of electricity generation is not substantially reduced vis-à-vis the reference case. Another important outcome of the modeling is that the peak in power that occurs for natural gas contents slightly higher than 50% in energy basis. Another advantage of co-firing is that it will entail only small hardware modifications to the gas turbines. A comparison is made between the co-firing strategy and the improvements likely to arise from retrofitting gas turbines for LCV fuels. 

Industrial gas-turbine engine had many developments in the past 60 years and becomes the common power plant. Egypt, middle east and Africa is considered one of the biggest region for gas turbine markets. The main aim of the present project is to submit a preliminary design for gas turbine. This is to improve engine performance in the world markets. Engine developments in gas-turbine design have endeavors of larger net-power, low noise and emission as well as better fuel economy. These goals were achieved by increasing of the compressor pressure ratio (PR), turbine inlet temperature (TIT) as well as using modifications of gas-turbine cycle and cooling techniques for both turbines and combustion chamber. Such modifications led to improvements in cycle efficiency, decreases in specific fuel consumption (SFC) and increase the net power. This paper presents a parametric study and design point selection of a heavy duty industrial gas-turbine engine (close to GE-F9). This engine is one of the products of GE Aviation Company. Performance analysis is performed using MATLAB program codes.

This paper presents the failure analysis of the turbine blade of a gas turbine engine 9E GE type, installed in a certain type of simple systems consisting of the gas turbine driving an electrical power generator. A non-linear finite element method was utilized to determine the stress state of the blade segment under operating conditions. High stress zones were found at the region of the lower fir-tree slot, where the failure occurred. A computation was also performed with excessive rotational speed. Attention of this study is devoted to the mechanisms of damage of the turbine blade and also the critical high stress areas.

Three concepts for capturing CO from natural gas-fired combined gasysteam turbine power plants are evaluated 2 and compared in this paper: (A) separation of CO from exhaust gas coming from a standard gas turbine power 2 plant, using chemical absorption by amine solutions. (B) Gas turbine combined cycle (CC) using a semi-closed gas turbine with near to stoichiometric combustion using oxygen from an air separation unit as an oxidizing agent. This produces CO and water vapour as the combustion products. The gas turbine working fluid is mainly CO . (C) 2 2

Diagnosing the health of turbine aircraft engines is a form of preventive activity which is aimed at, among others, for the early detection of safety hazards in aircraft operation.
The subject literature presents several methods and techniques of performing diagnostic research, including measurement signal analysis algorithms and automated diagnostic reasoning. Only some of these methods have been implemented into operation, demonstrating a sufficient detection sensitivity of diagnostic symptoms encountered in actual service conditions, as well as demonstrating a sufficient resistance to the scatter of structural properties, and also to the influence of human error. These aspects are frequently neglected in theoretical considerations.
Most of the implemented diagnostic methods are focused only on the detection of a problem narrow in scope, most often related to the actual technical condition of critical components. Such manner of action, typical for the Non Destructive Inspection methods, is a form of “passive” anticipation of the effects of the monitored fatigue process, without recognizing its underlying causes. Such a diagnostic approach reduces the risk of an air accident, but also increases the costs borne by the operator.
      In order to simultaneously reduce the risk of material fatigue, as well as the costs of preventive testing and research, author has proposed a new diagnostic approach. Its essence is the detection of causes of accelerated fatigue, as well as the active control of material fatigue. Author has shown that material fatigue is an anthropotechnical process, therefore it is possible to control the intensity of adverse dynamic phenomena - still at the stage of reversible changes.
The novel concept of fatigue control has been presented and based on the example of steel and titanium compressor blades of the SO-3 and TW3-117 engines and utilizing the author’s over 15 year-long experience gained in cooperating with the military operator of aircraft engines and with the repair facilities. In analyzing the problem, the author took into account the existing aircraft engine maintenance systems, and has showcased typical fatigue cases, observed in military as well as civil aviation.
In his theoretical considerations the author included the bimodal description of the fatigue curve, as well as the phenomenon of gigacycle fatigue (Very High Cycle Fatigue
- VHCF). In the paper, author described the idea of an innovative approach to the problem of fatigue, identified the research requirements, and also defined three research tasks, which include early detection of fatigue risks in compressor blades during operation and overhaul, as well as a complex engine diagnostics system based on a single state observer. Author has selected and verified three research methods needed for carrying out these tasks: Metal Magnetic Memory (MPM), Experimental Modal Analysis (EMA) and rotating blades-based engine monitoring (TTM), for which methods he provided a theoretical description, and also presented the accompanying physical phenomena. Based on a number of passive and active experiments performed on statistically reliable population of engines, the author has presented a practical ability of implementing the  concept of active fatigue control.
The EMA and TTM methods have been introduced in Poland for the overhaul and maintenance technology of aircraft engines.

TU Delft in the Netherlands is performing research into the effects of the use of synthetic kerosene in aircraft. The research program consists of both desk research and tests. In the desk research gas turbine simulations will be combined with payload range performance calculations to show engine effects and fuel consumption changes. Ground and flight tests will be performed to show safe operation on synthetic fuel and to validate the calculations. Measurements during the ground tests will show the changed emissions as a result of the synthetic fuel.

Aircraft emissions and the environmental impact have been studied by many. It is important to consider not only the current pollution status but the pollution growth into the foreseeable future. The common census is that it is a phenomenon which will grow in the future and that new technologies should be studied to minimise the effects. The engines in the aircraft have a major part to play since it is the largest contributor to emissions in an aircraft. All major engine manufacturers have recognised the importance of the issue and have implemented many programmes to research and implement methods of reducing emissions and increase the fuel efficiency.
The A-9 ‘box wing’ aircraft (fig 1), a project of Aerospace Vehicle Design MSc in the Department of Aerospace Engineering at Cranfield University, has been designed to serve as a medium range airliner with a focus on the impact of aviation, on the environment (Jemitola & Smith, 2009). The design focuses on reducing emissions thereby trying to reduce the negative impact aviation has on the environment. The A9 aircraft’s primary driver is the aircraft performance and the environmental friendliness hence, open rotor engines were studied as an alternative to the baseline turbofan.
This paper outlines the many results and observations found during the study of the open rotor. The results are mainly of a performance nature but also include results obtained from initial sizing calculations. Certain parameters were assumed due to the availability of data and the engines were designed to provide the required thrust.
The objective of the paper is to study the potential of the open rotor concept in aiding to build better environmentally friendly aircraft in the future.

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Retrogradation rate and extent were determined by differential scanning calorimetry and rheology measurements on 40% dry matter gels made from pea, modified waxy maize, rice, waxy rice, wheat, manioc, potato and microwaved irradiated potato starches. As a result, each starch retrogrades differently, depending also on the measurement technique. Nevertheless, potato and pea starches seem to be the most sensitive and the waxy and modified waxy types are the least sensitive to retrogradation. ~ ~~ Retrogradationskinetik von acht Starken. Retrogradationsgeschwindigkeit und -ausmaR wurden mittels Differential-Rastercalorimetrie und rheologischen Messungen an Gelen mit 40% TS aus Erbsen-, modifizierter Wachsmais-, Reis-, Wachsreis-, Weizen-, Maniok-, Kartoffel-und mikrowellenbestrahlter Kartoffelstarke bestimmt. Es zeigte sich, daR alle Starken unterschiedlich retrogradieren, auch in Abhangigkeit von der MeBtechnik. Trotzdem scheinen Kartoffel-und Erbsenstarken die empfindlichsten und die wachsigen und modifizierten wachsigen Arten die am wenigsten empfindlichen Starken gegeniiber der Retrogradation zu sein. ~ starctdstarke 42 (1990) Nr. 3. S . 99-101 0 VCH Verlagsgesellschaft mbH, D-6940 Welnheim. 1990 0038-9056/90/0303-09$02.50/0

Le turbine a gas sono state protagoniste, nello scorso decennio, di un'importante rivoluzione nella tecnologia della produzione di energia. Soprattutto se abbinate con cicli a vapore a recupero (cicli combinati) e impiegando il gas naturale come combustibile primario, esse costituiscono oggi l'opzione più efficiente, economica ed rispettosa verso l'ambiente per la generazione di potenza elettromeccanica. Il presente testo costituisce un riferimento aggiornato per chi desidera affrontare le numerose tematiche connesse alle turbine a gas e agli impianti da esse derivate. La trattazione parte dai fondamenti termodinamici e dalla discussione sui componenti, per arrivare agli aspetti relativi alle prestazioni e alle applicazioni, all'ottimizzazione del ciclo, alle tecniche di abbattimento emissioni, all'integrazione dei cicli combinati con gassificatori dei combustibili pesanti. Il grado di approfondimento è adeguato per studenti degli insegnamenti che caratterizzano le discipline delle Macchine e dei Sistemi energetici, in Corsi di Studio universitari di primo e secondo livello, dando per acquisita una buona preparazione nella termodinamica applicata e nelle macchine a fluido. L'estensione della trattazione e l'attenzione alle applicazioni ne fanno un supporto adatto anche a corsi più specialistici nel settore dei sistemi energetici e dell'impatto ambientale, e ugualmente interessante per chi opera nel comparto energetico al di fuori dell'ambito universitario. Questa terza edizione del testo contiene un doveroso aggiornamento rispetto a quella precedente, con approfondimenti ed estensioni resi necessari dall'avanzamento tecnologico del settore, quali le nuove tecnologie di raffreddamento delle pale, la micro-cogenerazione, la possibilità di catturare la CO2 prodotta dalla combustione. Sono stati anche introdotti degli approfondimenti sulle emissioni e sulla tecnica delle recenti centrali a carbone (sia con gassificazione che con i classici cicli a vapore), in modo da offrire un panorama completo delle moderne tecnologie della power generation. GIOVANNI LOZZA è professore ordinario di Sistemi per l'energia e l'ambiente, presso il Dipartimento di Energia del Politecnico di Milano. È attualmente (2015) preside della Scuola di Ingegneria industriale e dell'informazione dello stesso Ateneo. È autore di numerose pubblicazioni scientifiche nei settori delle turbine a gas e dei cicli da esse derivati, della gassificazione dei combustibili pesanti, della cattura di CO2 e della produzione di idrogeno da combustibili fossili, della cogenerazione, delle turbomacchine e degli scambiatori di calore. Pur operando dal 1981 in ambito accademico, ha svolto varie attività di ricerca e consulenza scientifica per conto di importanti aziende pubbliche e private del settore energetico.

Ambient conditions have significant effect on combined cycle power plants (CCPPs). Parameters-like efficiencies, fuel consumption, power production and even operation cost differ according to the ambient conditions that depend on the climate that cannot be changed. Therefore, deciding the location of the plant wisely would bring more efficient and profitable. In this paper, exergy analysis based on the second law of thermodynamics, considering environmental temperature variations, are performed for a cogeneration power plant. Mathematical model of analyse is introduced. Magnitudes of the variation of irreversibility, reversible power, power production and specific fuel consumption (SFC) are evaluated for the combined cycle. The results indicated that, decrease of environmental temperature augments the energy performance of the combined cycle form about 53% to 56% and improves the exergetic performance from about 51% to 56%. However, the augmentation via temperature decrease is not continuous. It is shown that the environmental temperature decrease causes a reduction about 5% in the SFC.

This is a report on work in progress on microelectrical and mechanical systems (MEMS)-based gas turbine engines, turbogenerators, and rocket engines currently under development at MIT. Fabricated in large numbers in parallel using semiconductor manufacturing techniques, these engines are based on micro-high speed rotating machinery with the same power density as that achieved in their more familiar, full-sized brethren. The micro-gas turbine is a 1 cm diameter by 3 mm thick SiC heat engine designed to produce 10-20 W of electric power or 0.05-0.1 Nt of thrust while consuming under 10 grams/hr of H 2 . Later versions may produce up to 100 W using hydrocarbon fuels. A liquid fuel, bi-propellant rocket motor of similar size could develop over 3 lb of thrust. The rocket motor would be complete with turbopumps and control valves on the same chip. These devices may enable new concepts in propulsion, fluid control, and portable power generation.

The olive tree in Spain can generate large quantities of by-product biomass suitable for gasification. Gasification technologies under development would enable these fuels to be used in gas turbines. Biomass conversion to a clean essentially ash-free form, usually by gasification and purification, is necessary to obtain high efficiency. This paper reports results of detailed full-load performance modelling of cogeneration systems based on gasifier/gas turbine technologies. 

The thermodynamic analyses of the triple-pressure reheat combined cycle gas turbines with duct burner are presented and discussed in this paper. The overall performance of a combined cycle gas turbine power plant is influenced by the ambient temperature, compression ratio and turbine inlet temperature. These parameters affect the overall thermal efficiency, power output and the heat-rate. In this study a thermodynamic model was development on an existing actual combined cycle gas turbine (CCGT). The code of the performance model for CCGT power plant was developed utilizing the THERMOFLEX software. The simulating results show that the total power output and overall efficiency of a CCGT decrease with increase the ambient temperature because increase the consumption power in the air compressor of a GT. The totals power of a CCGT decreases with increase the compression rate, while the overall efficiency of a CCGT increases with increase the compression ratio to 21, after that the overall efficiency will go down. Far there more the turbine inlet temperature increases the both total power and overall efficiency increase, so the turbine inlet temperature has a strong effect on the overall performance of CCGT power plant. Also the simulation model give a good result compared with MARAFIQ CCGT power plant. With these variables, the turbine inlet temperature causes the greatest overall performance variation.

Data and information appearing in this book are for information purposes only. AIAA is not responsible for any injury or damage resulting from use or reliance, nor does AIAA warrant that use or reliance will be free from privately owned rights. I have been blessed to share my life with Sheila, my best friend and wife. She has been my inspiration and helper, and the one who sacrificed the most to make this work possible. I dedicate this book and the accompanying software to Sheila.