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In this study, the performance analysis of the split flow turbofan engine with afterburners has been examined using the parametric cycle analysis method. The purpose of this study is to examine how engine performance is impacted by design parameters and flight ambient values and to develop a software in this context.

Software has been developed using the open-source PYTHON programming language to perform performance analysis. Mach number, compressor/fan pressure ratio, bypass ratio and density were used as parameters. The effects of these variables on engine performance parameters were investigated.

Parametric cycle analysis has been calculated for different flight conditions in the range of 0–2 M and 0–15,000 m altitude for turbofan engines. With this study, basic data were obtained to optimize according to targeted flight conditions.

As a result of the performance analysis, the association between the flight conditions and design parameters of engine were determined. A software has been developed that can be used in the design of supersonic gas turbine engines for fast and easy simulation of the design parameters.

The variables used in the literature have been analyzed, and the results of the studies have been incorporated into the developed software, which can be used in innovative engine design. Software is capable to be developed further with the integration of new algorithms and models.

With the condition monitoring system on airplanes, failures can be predicted before they occur. Performance deterioration of aircraft engines is monitored by parameters such as fuel flow, exhaust gas temperature, engine fan speeds, vibration, oil pressure and oil temperature. The vibration parameter allows us to easily detect any existing or possible faults. The purpose of this paper is to develop a new model to estimate the low pressure turbine (LPT) vibration parameter of an aircraft engine by using the data of an aircraft’s actual flight from flight data recorder (FDR).

First, statistical regression analysis is used to determine the parameters related to LPT. Then, the selected parameters were applied as an input to the developed Levenberg–Marquardt feedforward neural network and the output LPT vibration parameter was estimated with a small error. Analyses were performed on MATLAB and SPSS Statistics 22 package program. Finally, the confidence interval method is used to check the accuracy of the estimated results of artificial neural networks (ANNs).

This study shows that the health conditions of an aircraft engine can be evaluated in terms of this paper by using confidence interval prediction of ANN-estimated LPT vibration parameters without dismantling and expert knowledge.

With this study, it has been shown that faults that may occur during flight can be easily detected using the data of a flight without expert evaluation.

The health condition of the turbofan engine was evaluated using the confidence interval prediction of ANN-estimated LPT vibration parameters.

This paper seeks to evaluate the potential of heat exchanged aeroengines for future Unmanned Aerial Vehicle (UAV), helicopter, and aircraft propulsion, with emphasis placed on reduced emissions, lower fuel burn, and less noise.

Aeroengine performance analyses were carried out covering a wide range of parameters for more complex thermodynamic cycles. This led to the identification of major component features and the establishing of preconceptual aeroengine layout concepts for various types of recuperated and ICR variants.

Novel aeroengine architectures were identified for heat exchanged turboshaft, turboprop, and turbofan variants covering a wide range of applications. While conceptual in nature, the results of the analyses and design studies generally concluded that heat exchanged engines represent a viable solution to meet demanding defence and commercial aeropropulsion needs in the 2015‐2020 timeframe, but they would require extensive development.

As highlighted in Parts I and II, early development work was focused on the use of recuperation, but this is only practical with compressor pressure ratios up to about 10. For today's aeroengines with pressure ratios up to about 50, improvement in SFC can only be realised by incorporating intercooling and recuperation. The new aeroengine concepts presented are clearly in an embryonic stage, but these should enable gas turbine and heat exchanger specialists to advance the technology by conducting more in‐depth analytical and design studies to establish higher efficiency and “greener” gas turbine aviation propulsion systems.

It is recognised that meeting future environmental and economic requirements will have a profound effect on aeroengine design and operation, and near‐term efforts will be focused on improving conventional simple‐cycle engines. This paper has addressed the longer‐term potential of heat exchanged aeroengines and has discussed novel design concepts. A deployment strategy, aimed at gaining confidence with emphasis placed on assuring engine reliability, has been suggested, with the initial development and flight worthiness test of a small recuperated turboprop engine for UAVs, followed by a larger recuperated turboshaft engine for a military helicopter, and then advancement to a larger and far more complex ICR turbofan engine.

A two‐dimensional high‐bypass ratio turbofan performance model was developed in order to predict accurately gas turbine transient performance. In the present model, the fan of high bypass engines has strong radial profiles of all thermodynamic variables. It is common to average these profiles so that the fan can be represented by one or two one‐dimensional characteristics. The present paper describes how the radial profiles can be used to make an estimation of turbofan transient performance. The results are somewhat different to those produced using two one‐dimensional compressor performance maps.

The purpose of this paper is to present a multi‐objective and multi‐point optimization method to support the preliminary design of an unmixed turbofan mounted on a sample UAV/UCAV aircraft.

An in‐house multi‐objective evolutionary algorithm, a flight simulator and a validated engine simulator are implemented and joined together using object‐oriented programming.

Optimal values are found of the pressure ratio and corrected mass flow of both the engine fan and compressor as they operate in on/off design conditions (multipoint approach), as well as the engine by‐pass ratio, that contextually minimize time and engine fuel consumption required to cover a fixed trajectory (mission profile). Furthermore, the optimal distribution of the thermodynamic quantities along the trajectory is determined.

The research deals with a preliminary design of an engine, therefore no detailed engine geometry can be found.

The paper shows how a multiobjective and multipoint approach to the design of an engine can affect the choice of the engine architecture. In particular, major practical implications regard how the mission profile can affect the choice of the design point: in fact, there is no longer a definitive design point but the design of a UAV/UCAV should be addressed as a function of the mission profile.

The paper presents a multiobjective and multipoint approach to engine optimization as a function of the mission profile.

The purpose of this paper is to examine the effects of heat capacity and density of biofuels on aircraft engine performance indicated by thrust and fuel consumption.

The influence of heat capacity and density was examined by simulating biofuels in a two-spool high-bypass turbofan engine running at cruise condition using a Cranfield in-house engine performance computer tool (PYTHIA). The effect of heat capacity and density on engine performance was evaluated through a comparison between kerosene and biofuels. Two types of biofuels were considered: Jatropha Bio-synthetic Paraffinic Kerosene (JSPK) and Camelina Bio-synthetic Paraffinic Kerosene (CSPK).

Results show an increase in engine thrust and a reduction in fuel consumption as the percentage of biofuel in the kerosene/biofuel mixture increases. Besides a low heating value, an effect of heat capacity on increasing engine thrust and an effect of density on reducing engine fuel consumption are observed.

The utilisation of biofuel in aircraft engines may result in reducing over-dependency on crude oil.

This paper observes secondary factors (heat capacity and density) that may influence aircraft engine performance which should be taken into consideration when selecting new fuel for new engine designs.

It is essential to develop more environment-friendly energy systems to prevent climate change and minimize environmental impact. Within this scope, many studies are performed on performance and environmental assessments of many types of energy systems. This paper, different from previous studies, aims to prove exergy performance of a low-emission combustor of an aero-engine.

It is a well-known fact that, with respect to previous exergy analysis, highest exergy destruction occurs in the combustor component of the engine. For this reason, it is required to evaluate a low-emission aero-engine combustor thermodynamically to understand the state of the art according to the authors’ best of knowledge. In this framework, combustor has been operated at numerous conditions (variable engine load) and evaluated.

As a conclusion of the study, the impact of emission reduction on performance improvement of the aero-engine combustors exergetically is presented. It is stated that exergy efficiency of the low-emission aero-engine combustor is found to be 64.69, 61.95 and 71.97 per cent under various operating conditions.

Results obtained in this paper may be beneficial for researchers who are interested in combustion and propulsion technology and thermal sciences.

Different from former studies, the impact of operating conditions on performance of a combustor is examined from the viewpoint of thermodynamics.

IT is nearly fifteen years since the introduction into civil operations of the Dart turboprop in the Vickers Viscount and the Ghost turbojet in the dc Havilland Comet. For many years it was thought that the turboprop would remain dominant in the short and medium haul classes, but the continued demand for higher cruising speeds and the passenger appeal of the jet have been largely responsible for the turboprop aircraft being superseded by the new generation of turbofan aircraft.

Pratt & Whitney Aircraft's F100 augmented turbofan is the most advanced military engine in service today. It powers two of the U.S. Air Force's front‐line fighters: the twin‐engine McDonnell Douglas F‐15 and the newly introduced single‐engine General Dynamics F‐16. The F100 is a 25,000‐pound‐thrust class engine. Yet it weighs only 3,020 pounds. No other military aircraft engine can match its remarkable 8‐to‐1 thrust‐to‐weight ratio. But the F100's unparalleled performance was marred by an unexpected problem: early production models were susceptible to a curious phenomenon called stagnation. When an F100 stagnates, it won't respond to its throttle. Thrust drops sharply, and the engine's turbine stages may overheat. The only way out of stagnation is to shut down the engine and restart it. Recently, P&WA engineers — working with technical investigators from the U.S. Air Force and McDonnell Douglas — unlocked the mystery of stagnation. Their success represents a significant advance in the technology of high‐performance turbofan engines.

The purpose of this paper is to present an acoustics-based method for measuring turbofan nozzle exhaust thrust, while assessing the potential of scaling the methods for in-flight measurements.

Although many methods proposed for achieving in-flight thrust measurements involve complicated, sensitive and expense instruments, an acoustics-based approach is discussed that greatly simplifies the technology development pathway to in-flight applications.

Results are provided for a minimum set of sensors applied in the exhaust of a research turbofan engine at Virginia Tech, showing the difference in acoustics-measured thrust and nozzle thrust found by integrating thermocouple and Kiel probe measurements to be less than 6 per cent at the maximum fan speed examined.

Measuring accurate thrust values in flight will prove immediately valuable for installed thrust validation and engine health monitoring. Acoustics-based methodologies are attractive because of the robustness and low cost of sensors and sources. The value of in-flight thrust measurements, along with the benefits of acoustic approaches, makes the current topic of great interest for further development.

This paper presents unique applications of a time-of-flight acoustic thrust sensor, while providing an original assessment of technological challenges involved with the progression of the technique for in-flight measurements.