Gas Turbine Research Articles

Innovative biomass cogeneration system for a zero energy school building

This study presents a detailed analysis of a Co-generation system specifically designed to fulfill energy (Electricity – Cooling – Heating) requirements of a Zero energy building (ZEB) school in Dubai. The proposed system integrates an electric compression chiller, which plays a crucial role in efficiently managing both heating and cooling demands within the educational facility. To generate clean electricity, the system utilizes a combination of advanced technologies, including a steam Rankine cycle turbine, an organic Rankine cycle turbine, and a gas turbine. The main goal of this research is to supply the definition of a ZEB by providing energy consumed by Zero Energy school building (ZESB) with a biomass system. To optimize energy consumption within the building, the innovative Building Energy Optimization Tool (BEopt) is employed, providing insights into energy efficiency improvements. Optimization of the biomass-based energy production system are executed applied EES software (Engineering Equation Solver) alongside the response surface methodology, ensuring a robust analytical framework for performance evaluation. The suggested co-generation consisted of modified Brayton cycle units (biogas fuel), steam Rankine cycle, organic Rankine cycle, and compression chiller for electricity generation, cooling, and heating. Annual energy consumption metrics for the school indicate a total electricity usage of 43,539.48 kWh, with a heating load of 0.94 kWh and a cooling load of 1,115.68 kWh. Through strategic optimization of energy consumption patterns, the system achieves a notable reduction in carbon dioxide emissions, amounting to 24,548.97 kg per year. The optimized energy system operates with an overall efficiency of 31.79% and incurs operational costs estimated at $88.02 per hour. In terms of output generation, the biomass energy system is projected to yield approximately 151,746,087 kWh of electricity, 194,610,878 kWh of heating bar, and 158,962,204 kWh of cooling bar annually. Comparative analysis demonstrates that this innovative biomass-based energy system can effectively meet the school’s energy demands throughout the year while contributing to sustainability goals and reducing environmental impact. A comparison of the school’s consumption and the system’s production showed that 151,702,547.5 kWh of electricity, 194,609,762.3 kWh of heating, and 158,774,864.1 kWh of cooling could be saved in one year to offset costs of co-generation systems. This research underscores the potential for integrating diversified renewable energy technologies in educational settings, thereby promoting sustainable practices within the context of Dubai’s commitment to supplying ZEB consumption in its ZEBs by 2050.

Aviation gas turbine engine bearings faults diagnosis method based on multi-parameter fusion criterion judgment and AO-PNN

Aviation gas turbine engine bearings faults diagnosis method based on multi-parameter fusion criterion judgment and AO-PNN

Problem driven innovation design strategies research for product manufacturing process

As a prerequisite and foundation for production and manufacturing, the design of product manufacturing process plays a crucial role in improving production efficiency, controlling resource consumption, shortening production cycles, and reducing processing costs. With the rapid development of advanced manufacturing technologies, product manufacturing process design is increasingly characterized by ambiguity, multi-solution possibilities, and cross-disciplinary integration, posing higher demands on enterprises’ capabilities in process design and innovation. To identify and innovatively address these issues within complex product manufacturing process, this study proposes a problem-driven innovation design strategy model for product manufacturing process. In the problem identification phase, opportunities are identified and categorized based on the product context and manufacturing process, followed by problem identification and the construction of problem elements using problem analysis methods. After identifying the problems, the type of innovation required is determined, and corresponding methods are applied to generate a set of solutions with innovation potential. These solutions are then evaluated and validated to determine the optimal innovation design for the product manufacturing process. If a solution fails validation, the problem is re-identified or re-solved, and the above steps are repeated until a validated final solution is achieved. Finally, the feasibility of the proposed strategy is demonstrated through a case study on the innovation design of the wax pattern manufacturing process for gas turbine blades.

Numerical Investigation on Effect of Thermal Barrier Coatings on Gas Turbine Combustor

Abstract—Thermal barrier coatings (TBCs) are critical for enhancing the performance and durability of gas turbine combustors by insulating metal components from extreme combustion temperatures. This project aims to conduct a comprehensive numerical investigation to evaluate the effects of TBCs on the thermal and fluid dynamics within gas turbine combustors. By using computational fluid dynamics (CFD) and heat transfer simulations, the study will analyze how different TBC materials, thicknesses, and configurations impact the overall combustion performance, including temperature distribution, thermal stresses, and efficiency. The study will simulate various operating conditions to investigate the behavior of coated and uncoated turbine surfaces. Key objectives include determining the reduction in surface temperatures of turbine blades, evaluating thermal gradient control, and assessing the influence of TBCs on component life and fuel efficiency. The results provide insights into optimizing TBC applications to enhance gas turbine performance and durability. The obtained results provided insights into the optimal application of TBCs and various materials as TBC, highlighting their potential to extend component lifespan and enhance gas turbine efficiency. This investigation will contribute to the ongoing efforts in improving gas turbine technology, with implications for aerospace and power generation sectors, ultimately leading to more sustainable and efficient energy solutions. Keywords—Thermal Barrier Coatings, Gas Turbine Combustor, Computational Fluid Dynamics, Heat Transfer, Thermal Management, Combustor Efficiency.

Simplified Data-Driven Models for Gas Turbine Diagnostics

The maintenance of gas turbines relies a lot on gas path diagnostics (GPD), which includes two approaches. The first approach employs a physics-based model (thermodynamic model) to convert measurement shifts (deviations) induced by deterioration into fault parameters, which drastically simplify diagnostics. The second approach relies on data-driven models, makes diagnosis in the space of measurement deviations, and involves pattern recognition techniques. Although a thermodynamic model is an essential element of GPD, it has limitations. This model is a complex software critical to computer resources, and the computation sometimes does not converge. Therefore, it is difficult to use the model in online applications. Since the 1990s, we have developed many thermodynamic models for different engines. Since the 2000s, simplified data-driven models were investigated. This paper proposes to substitute a thermodynamic model for novel simplified data-driven models that have the same functionality, i.e., take into consideration the influence of both operating conditions and engine faults. The proposed models are formed and compared with the underlying thermodynamic model. To obtain a solid conclusion about these models, they are verified in twelve test cases formed by three test-case engines, two model types, and two approximation functions. Although the accuracy of the simplified models varies from 1.15% to 0.0082%, it was found acceptable even for the worst case. Thus, these simple-but-accurate models with the functionality of a physics-based model represent a good replacement for the latter. It is expected that the models will stimulate the further development of advanced diagnostic systems.

Effects of SO2 on the long-term corrosion behaviour of K452 superalloy

The corrosion behaviour of a nickel-based superalloy K452 in a simulated gas turbine blade service environment (Air+2 vol.% SO2) at 900 °C up to 2000 h was investigated by both microstructural characterization and the Molecular Dynamics (MD) calculations. The mass gain of K452 alloy is increased from 4.12 mg/cm² to 6.64 mg/cm² by the induce of SO2. The formation of numerous voids and pits in the corrosion layer is caused by the presence of SO2. After long-term corrosion, an outer layer with Ni enriches form since the outward diffusion of Ni from the substrate to the outer corrosion layer is promoted by the enhanced chemical potential gradient. The repeated oxidation and sulphidation of Ni-rich sulphides in the outer layer is the main reason for long-term corrosion degradation of the alloy.

Investigating the effect of struts arrangement on the mechanical characterization of the gas turbine power section

Purpose Gas turbines are recognized as important equipment in industries, and struts in a gas turbine are important components that keep rotary and stationary components concentric together. The arrangement of struts affects the air-flow, temperature distribution and mechanical characteristics of a gas turbine. There is limited research on the mechanical effects of struts arrangement on turbine behavior. The purpose of this study is to investigate the effect of strut arrangement on the mechanical characteristics of gas turbines in order to achieve a better turbine design, resulting in lower in-service stress and longer working lifetimes. Design/methodology/approach In this research, experimental data, three-dimensional modeling and finite-element analysis have been used. In this way, the five common arrangements of struts were studied. The natural frequency, stress distribution and buckling load of struts in each arrangement were investigated, and the effect of struts on critical points of the gas turbine was evaluated. Findings The analysis of the results revealed that tangential strut arrangements have a higher natural frequency than radial arrangements by up to 35.5%. Stress distribution and the position of maximum stress are dependent on the strut arrangement. Maximum stress could be reduced by over 44.5% depending on the arrangement of the struts. Also, radial strut arrangements have a buckling load 12.6 times higher than tangential arrangements due to using struts with shorter lengths. Originality/value The arrangement of struts has an important effect on the air-flow, temperature distribution and mechanical characteristics of a gas turbine. Most research has focused on the effect of struts on the air-flow and temperature of gas turbine diffusers, and there is limited research on the mechanical effects of struts arrangement on the gas turbines. In this research, the effect of strut arrangement on the mechanical characteristics of gas turbines including natural frequency, stress distribution, buckling load and critical points was investigated.

Creating a quasi-linear model of an elastic damper support of the gas turbine engine rotor

Creating a quasi-linear model of an elastic damper support of the gas turbine engine rotor

Method for searching defects in gas turbine engine blades under visible light using the U-NET model

Method for searching defects in gas turbine engine blades under visible light using the U-NET model

Thermo-Economic and Environmental Analysis of a SOFC-Based Novel Power Generation System Formed with Gas Turbine and Modified Organic Flash Rankine Cycle

Thermo-Economic and Environmental Analysis of a SOFC-Based Novel Power Generation System Formed with Gas Turbine and Modified Organic Flash Rankine Cycle

Fracture characteristics of rare-earth phosphate and silicate environmental barrier coatings under molten CMAS corrosion

The fracture characteristics of rare-earth phosphate (LuPO4) and silicate (Lu2SiO5) environmental barrier coating (EBC) materials under molten calcium–magnesium aluminosilicate (CMAS) corrosion are analyzed. EBCs are crucial for protecting SiC-based ceramic matrix composite components in the hot section of gas turbine engines. Recently the rare-earth phosphates as EBC materials have shown better performance than third-generation rare-earth silicates under CMAS corrosion. However, the fracture of EBCs under CMAS corrosion during service remains a significant concern. This work investigates the fracture characteristics of LuPO4 and Lu2SiO5 using a combined experimental and computational approach. The computational model uses experimental micrographs and material properties obtained from fabricated EBC samples for fracture simulations. The simulation results are compared with experimental fracture toughness data and validated using statistical tests (p < 0.01). The results show significant degradation in fracture strength of EBC materials caused by CMAS penetration. EBC materials lost more than 40% of their initial fracture strength even at low penetration levels of 3% by volume. Simulation results show that LuPO4 degraded more than Lu2SiO5. However, experimental observations from CMAS reaction tests demonstrate that LuPO4 may exhibit higher fracture resistance than Lu2SiO5 under similar CMAS corrosion conditions due to the formation of dense and thick passivation reaction layer. The insights gained from this study could be used to design EBCs with improved fracture resistance under CMAS corrosion.

An approach to building an emergency reserve within the framework of comprehensive maintenance contract for industrial gas turbine engines: The case of the Bovanenkovskoye field

Subject. The article discusses the emergency reserve fund of spare parts for the AL-31ST group of industrial gas turbine engines during their operation at the Bovanenkovskoye field of PAO Gazprom. Objectives. The purpose is to consider an approach to the formation of an emergency reserve fund of spare parts for engines during their operation at the Bovanenkovskoye field within the framework of comprehensive maintenance agreement with extended warranty obligations. Methods. The study employs analytical methods of ABC and FMR analysis to determine the range of spare parts, simulation modeling of engine operation to assess the impact of uncompensated single failure on the amount of forced downtime of gas pumping equipment and the effectiveness of comprehensive contract with extended warranty obligations. Results. The paper shows that a single failure of an unpaid spare part does not impair the effectiveness of the complex contract in question as compared to the traditional method of concluding contracts for industrial gas turbine engines maintenance. Conclusions. The ABC and FMR analysis enabled to reduce the required amount of financial resources when forming a warehouse of spare parts constituting the emergency reserve. Modeling helped establish that a single failure uncompensated by a spare part from the warehouse increases the amount of forced downtime of gas pumping equipment. At the same time, the effectiveness of comprehensive maintenance contract with extended warranty decreases, however, it remains attractive, compared to traditional methods of contracting.

Study on low-cycle fatigue life of nickel-based superalloy GH4586 at various temperatures

Abstract The nickel-based superalloy GH4586 has been more widely used as the main material for the preparation of aerospace turbine components. However, with the development of reusable rocket engine technology, a more profound understanding of the low-cycle fatigue performance of the material under cyclic loading is required. In this study, the same specification of GH4586 used in the turbine disk of an engine is used to prepare test specimens, the fatigue performance at different strain levels of 0.5, 0.7, 0.9 and 1% is investigated, and fatigue tests are carried out at six temperatures from room temperature to 1,173 K. The fatigue σ–N curves of the material are obtained. In this study, the cyclic hardening/softening transformation mechanism of GH4586 alloy and its influence on the life of turbine components are systematically revealed through low-cycle fatigue tests with multiple temperature points (room temperature to 1,173 K) and multiple strain amplitudes (0.5–1%). The study shows that optimizing the strain amplitude below 900 K can improve the component life by more than 20%, which provides a quantitative basis for the strain–temperature coupling design of reusable rocket engine turbine.

Part-load performance of a pure H 2 /O 2 gas turbine cooled by steam from a bottoming-cycle

Hydrogen energy is one of the most attractive renewable resources for mitigating environmental problems and achieving a zero-emission future. Hydrogen-fueled gas turbine power generation is one of the most promising technologies to utilize hydrogen energy. Due to the peak shaving tasks, hydrogen-fueled gas turbines often deviate from the design operating point. Therefore, in this paper, an analysis of the part load performance of a cooled three-spool pure hydrogen-fueled gas turbine for the R-Graz cycle is implemented. Both the mainstream working medium and coolant are steam. Considering the complex physical properties of steam, a novel equation for the evaluation of the mixing loss caused by film cooling is proposed to improve the accuracy of the assessment. Within the load range of 50% to 100%, the results indicate that the isentropic efficiency is dependent on the uncooled polytropic expansion and cooling process. Coolant consumption analysis under part load conditions reveals that the power turbine consumes more than half the coolant, while the high-pressure turbine uses less than 20%. The coolant consumption proportion of the three rotors basically does not change with the load. At last, the coolant cooling technology is considered to improve the total isentropic efficiency and reduce the coolant consumption.

Impact of Parameters on Gas Turbine Performance Using Energy Analysis

Gas turbine power plant performance was investigated using parametric analysis. Thermodynamic relationships were used to develop models that simulated the gas turbine performance under varying operating conditions. The gas turbine located at the Transcorp Power, Ughelli, Nigeria, was used for simulation employing MATLAB R2017b codes. The model demonstrated that the gas turbine performance is significantly influenced by operational parameters, for example, relative humidity (RH), compression ratio (CR), ambient temperature (AT) and turbine inlet temperature. The results showed that for every 0.7% increase in AT, compressor power consumption increased by 2.5%, and for every 25% increase in RH, compressor power requirement and heat supply increased by 55%. The efficiency analysis reveals that as RH increases from 40% to 50%, cycle efficiency decreases by 0.022%. Net power output increases as RH increases. Specific fuel consumption (SFC) increased as AT and compression ratio increased; a 2.25% increase in AT resulted in a 0.25% increase in SFC. A 1.85% increase in AT resulted in a 0.23% decrease in net power and a 0.68% decrease in net power output. According to the findings, increasing the CR and the temperature of the turbine inlet improves overall efficiency while decreasing AT. The thermal efficiency decreased with an increase in AT, whereas it increased as turbine inlet temperature increased. The CR, AT, and turbine inlet temperature are all major factors in the overall performance of a gas turbine. As a result, controlling the thermodynamic parameters is economically feasible for cycle performance and advantageous for gas turbine operations.

Transient Power Stabilization in Marine Microgrids: Improved Droop Control and Feedforward Strategies for Heterogeneous Gas Turbines with Hybrid Energy Storage

To address the complexity of power allocation in parallel operation systems combining single-shaft and split-shaft gas turbine generators, this paper proposes a coordinated power allocation strategy based on enhanced voltage droop control for marine power systems integrated with hybrid energy storage comprising flywheel and battery subsystems. Furthermore, to mitigate significant power sharing deviations during transient/pulsed load conditions in shipboard application, a feedforward compensation strategy is developed. Simulation results demonstrate that the improved droop control maintains power sharing deviations below 3.5% across steady-state operations and gradual load variations, ensuring system stability and balanced power distribution. However, abrupt load changes induce over 20% deviations, compromising parallel operation reliability. The proposed feedforward compensation strategy effectively restricts deviations within 4% under specified transient and pulsed load scenarios, satisfying both parallel operation criteria and grid power quality requirements. Validation is performed on a parallel system comprising two distinct gas turbine configurations.

Flame and flow characteristics of lean premixed turbulent NH3/H2/N2 - air flames with increasing Karlovitz numbers

Premixed flames of partially cracked ammonia (NH3) hold significant promise for the decarbonization of internal combustion engines and gas turbines, since they can burn at a similar laminar flame speed to methane but have notably high blow-out resistance. Understanding turbulent premixed flames with partially cracked NH3 is highly relevant from both academic and application perspectives. This study aims to enhance our understanding of such premixed NH3/H2/N2-air flames subjected to increasing turbulence. For this purpose, a specific fuel mixture, consisting of 40vol% NH3, 45vol% H2, and 15vol% N2, is selected to match the laminar flame characteristics of methane at the same equivalence ratio. Turbulent jet flames are stabilized in a piloted burner with increasing bulk velocities from 30 to 180 m/s and Karlovitz numbers from approximately 75 to 2,140. One-dimensional (1D) simulations of freely propagating flames and strained counter-flow flames are performed, emphasizing temperature and species axial profiles and flame response to strain rate. Further, turbulent flow and flame structures are characterized using simultaneous particle image velocimetry (PIV) and laser-induced fluorescence of OH radicals (OH-LIF) measurements. Flame surface density and curvature distributions are evaluated, revealing the dominant role of turbulence over differential diffusion in shaping the flame surface topology. It is also found that the OH intensity gradient serves as a marker for local reactivity and thermo-diffusive instabilities, being higher at positive curvatures than at negative ones. Flat flames dominate the surface topology but show significant discrepancies in as they appear both upstream and downstream of leading edges. The thickness of the OH layer is not broadened by turbulence, even at Ka = 2,140, suggesting that eddies cannot penetrate into the main reaction zone marked by OH radicals, which are formed at higher temperatures than the preheat layer.

Hot Corrosion Behavior and Damage Mechanism on Yield Property of Nickel-Based Superalloy

Ni-based superalloys with enhanced environmental resistance at high temperatures are crucial for advanced gas turbine engines. The new polycrystalline nickel-based superalloy has excellent mechanical properties, but as a low-Cr, high-alloying superalloy, its environmental resistance has never been investigated. The hot corrosion behavior of the nickel-based superalloy under molten salt conditions and its effect on its tensile properties were investigated in this paper. The results showed the following: The diffusion of the Cr, Al, and Ni elements governs the majority of the corrosion process, resulting in the production of an environmentally damaged organization with internal sulfidation and surface oxidation. The Wagner model predicts the inability to form a dense Al oxide scale on the surface because the crucial generation condition of external Al oxides is not met. In addition, the growth stress in the damage scales is the main cause of cracking and spalling in the isothermal corrosion process. Due to the increased local stress concentration brought on by this environmental degradation, the sulfide scale acts as a fracture source, guiding the matrix cracking and influencing the tensile properties of the alloy.

Experimental Characterization of Superheated Ammonia Spray From a Single-Hole Spray M Injector

Abstract The growing recognition of ammonia as a carbon-free alternative fuel for both transportation and power generation is underscored by numerous studies. While the use of gaseous ammonia injection has been extensively considered, research on the direct injection of liquid ammonia remains relatively scarce, especially in the case of internal combustion engines (ICE). The application of liquid ammonia in gas turbines offers economic and size-related advantages over gaseous ammonia injection. But the liquid ammonia's instantaneous spray flash-boiling and its high latent heat of vaporization induce the necessity of employing preheated swirling air to enhance flame stability, mitigating the strong cooling effect induced. The preference for direct injection of liquid ammonia is driven by its efficacy in controlling in-cylinder air–fuel ratios and optimizing thermal efficiency. This study presents macroscopic and near-field Schlieren measurements of a one-hole Engine Combustion Network (ECN) Spray M, representative of direct liquid injector for engine, with ammonia for different degrees of superheating. Spray angles and penetration length are provided as a function of the superheat degree with also a focus near the injector nozzle. Additionally, in-spray temperature measurements are presented, providing the first valuable information for modeling purposes.

Size-resolved measurements of the light absorption properties of soot aerosols from a gas turbine engine

The optical properties of soot are crucial in estimating its climate impact through direct radiative forcing. Soot light absorption is typically quantified by the mass absorption cross-section (MACλ) or the absorption function E(mλ), which are wavelength dependent. Light absorbed by soot can be predicted from its MACλ using mass-concentration measurements, or from its E(mλ) using material density and an optical model accounting for soot-aggregate morphology. Recent work has shown that the soot MACλ shows a size dependency, due to a size-dependent degree of graphitization. We therefore hypothesized here that a similar size dependency may be observed for E(mλ), which we quantify here. To test this hypothesis, we present a novel approach to obtain size-resolved MACλ and E(mλ) of soot from a gas turbine engine by combining pulsed laser-induced incandescence signals with total mass-concentration measurements. E(mλ) was found to vary with soot-particle size, with values ranging between 0.23 to 0.31 for the smallest (≈ 0.13 fg) and largest (≈ 3 fg) particles measured. To our knowledge, these measurements are the first to demonstrate that E(mλ) not only varies between soot samples, but also within a population of soot particles, which impacts the interpretation of optical diagnostics and prediction of the radiative properties of soot.