Nowadays, gas turbines play a significant role in industry and power generation units. Therefore, any increase in their performance efficiency, is designers' major concern. Power generation system's principal considerations are performance, weight and reliability. Gas turbine engine is considered as a probable choice for such applications. This research develops and validates a Bond Graph model based on flow of energy and information of a gas turbine engine. Here, modelling of the gas turbine engine is achieved based on the pseudo Bond Graph approach. Subsequently, by coupling the Bond-Graph component models, a unified framework for model representation is presented. Also, to study the effect of changing external load on turbine's performance, an industrial two-shaft gas turbine is simulated under large transient loads based on the previously developed component models. Finally, the commercial gas turbine simulation program (GSP) is used to validate the simulation results. Transient response simulations indicate an acceptable error between the GSP and Bond Graph model outputs.

The thermal management system architectures proposed for hydrogen-powered propulsion technologies are critically reviewed and assessed. The objectives of this paper are to determine the system-level shortcomings and to recognise the remaining challenges and research questions that need to be sorted out in order to enable this disruptive technology to be utilised by propulsion system manufacturers. Initially, a scientometrics based co-word analysis is conducted to identify the milestones for the literature review as well as to illustrate the connections between relevant ideas by considering the patterns of co-occurrence of words. Then, a historical review of the proposed embodiments and concepts dating back to 1995 is followed. Next, feasible thermal management system architectures are classified into three distinct classes and its components are discussed. These architectures are further extended and adapted for the application of hydrogen-powered fuel cells in aviation. This climaxes with the assessment of the available evidence to verify the reasons why no hydrogen-powered propulsion thermal management system architecture has yet been approved for commercial production. Finally, the remaining research challenges are identified through a systematic examination of the critical areas in thermal management systems for application to hydrogen-powered air vehicles’ engine cooling. The proposed solutions are discussed from weight, cost, complexity, and impact points of view by a system-level assessment of the critical areas in the field.

Following the technological advances in recent decades, advanced electronic systems linked to the gas turbine industry are increasingly considered by the designers of this field. For this purpose, new airborne systems in conjunction with jet engines are developed, which are incorporated in many challenging design problems such as control law and configuration design. Thus, a comprehensive modeling structure is needed that can bolster the integrity of the system development such as the bond graph approach, which is known as an efficient method for modeling complicated mechatronic systems. In this paper, modeling and simulation of a jet engine dynamic performance and aircraft motion are achieved based on the bond graph approach. At first, the electric starter bond graph model is constructed and physical relationships governing each engine component are obtained. In the aftermath, the modulated energy fields are developed for the jet engine components. Subsequently, the bond graph model of the engine is numerically simulated and experimentally tested and verified for a small jet engine. Finally, bond graph modeling and simulation of integrated engine and aircraft system is presented. The test results indicate the acceptable accuracy of the modeling approach which can be applied for innovative diagnosis and control systems design.

Improving the performance of industrial gas turbines has always been at the focus of attention of researchers and manufacturers. Nowadays, the operating environment of gas turbines has been transformed significantly respect to the very fast growth of renewable electricity generation where gas turbines should provide a safe, reliable, fast, and flexible transient operation to support their renewable partners. So, having a reliable tools to predict the transient behavior of the gas turbine is becoming more and more important. Regarding the response time and flexibility, improving the turbine performance during the start-up phase is an important issue that should be taken into account by the turbine manufacturers. To analyze the turbine performance during the start-up phase and to implement novel ideas so as to improve its performance, modeling, and simulation of an industrial gas turbine during cold start-up phase is investigated this article using an integrated modular approach. During this phase, a complex mechatronic system comprised of an asynchronous AC motor (electric starter), static frequency converter drive, and gas turbine exists. The start-up phase happens in this manner: first, the clutch transfers the torque generated by the electric starter to the gas turbine so that the turbine reaches a specific speed (cranking stage). Next, the turbine spends some time at this speed (purging stage), after which the turbine speed decreases, sparking stage begins, and the turbine enters the warm start-up phase. It is, however, possible that the start-up process fails at an intermediate stage. Such unsuccessful start-ups can be caused by turbine vibrations, the increase in the gradients of exhaust gases, or issues with fuel spray nozzles. If, for any reason, the turbine cannot reach the self-sustained speed and the speed falls below a certain threshold, the clutch engages once again with the turbine shaft and the start-up process is repeated. Consequently, when modeling the start-up phase, we face discontinuities in performance and a system with variable structure owing to the existence of clutch. Modeling the start-up phase, which happens to exist in many different fields including electric and mechanical application, brings about problems in numerical solutions (such as algebraic loop). Accordingly, this study attempts to benefit from the bond graph approach (as a powerful physical modeling approach) to model such a mechatronic system. The results confirm the effectiveness of the proposed approach in detailed performance prediction of the gas turbine in start-up phase.

A hardware-in-the-loop (HIL) test for a control unit of an industrial gas turbine engine is performed to evaluate the designed controller. Although the dynamic performance of the studied gas turbine is strictly related to the variable inlet guide vain (VIGV) position, one of the main challenges is to develop an engine model considering VIGV variations. The model should also be capable of real time simulation. Accordingly, the gas turbine is numerically modeled using bond graph concepts. To demonstrate the operational reliability of the engine’s control strategy, the control algorithm is implemented on an industrial hardware as an embedded system. This is then put into a HIL test along with the engine model. The actual component (controller) and the virtual engine model are the hardware and software parts of the HIL test, respectively. In this experiment, the interaction between the real part and the rest of the system is compared with that of the completely numerical model in which the controller is a simulated software-based model as is the engine itself. Finally, the results indicate that the physical constraints of the engine are successfully satisfied through the implementation of control algorithms on the utilized hardware.

A marine propulsion system is composed of several subsystems that operate in a variety of energy fields. The propulsion power of a ship can be provided from a two-shaft gas turbine. In this article, the modeling of a two-shaft gas turbine and its associated subsystems including gears, flexible couplings and clutch is considered. These components are connected in the form of a virtual marine propulsion system, which is based on the bond-graph approach. When a clutch is used in a propulsion system, discontinuities occur in the describing model, which leads to some challenging problems when performing computer simulations. The two main difficulties are the numerical stiffness and the variable model structure. In this research, the bond-graph method is adapted as the modeling framework in order to allow a constant system structure model that minimizes the stiffness problem. Next, simulation results of a two-shaft gas turbine are presented in the off-design condition and verified with experimental tests. These results demonstrate the acceptable accuracy of computer simulations. Also, the effects of clutch performance on the dynamics of the marine propulsion system are discussed.

The next generation of aerial robots will be utilized extensively in real-world applications for different purposes: Delivery, entertainment, inspection, health and safety, photography, search and rescue operations, fire detection, and use in hazardous and unreachable environments. Thus, dynamic modeling and control of drones will play a vital role in the growth phase of this cutting-edge technology. This paper presents a systematic approach for control mode identification of JetQuads (gas turbine-powered quads) that should be satisfied simultaneously to achieve a safe and optimal operation of the JetQuad. Using bond graphs as a powerful mechatronic tool, a modular model of a JetQuad including the gas turbine, electric starter, and the main body was developed and validated against publicly available data. Two practical scenarios for thrust variation as a function of time were defined to investigate the compatibility and robustness of the JetQuad. The simulation results of these scenarios confirmed the necessity of designing a compatibility control loop, a stability control loop, and physical limitation control loops for the safe and errorless operation of the system. A control structure with its associated control algorithm is also proposed to deal with future challenges in JetQuad control problems.

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