Blade Material Research Articles

Commercial Small-Scale Horizontal and Vertical Wind Turbines: A Comprehensive Review of Geometry, Materials, Costs and Performance

The effective exploitation of renewable energy sources is one of the most effective solutions to counter the energy, environmental and economic problems associated with the use of fossil fuels. Small-scale wind turbines (converting wind energy into electric energy with a power output lower than 50 kW) have received tremendous attention over the past few decades thanks to their reduced environmental impact, high efficiency, low maintenance cost, high reliability, wide wind operation range, self-starting capability at low wind speed, limited installation space, reduced dependence on grid-connected power and long transmission lines, low capital costs, as well as the possibility to be installed in some urban settings. However, there are significant challenges and drawbacks associated with this technology from many different perspectives, including the significant discrepancy between theoretical performance data provided by the manufacturers and real field operation, that need to be investigated in greater depth in order to enable a more widespread deployment of small-scale wind turbines. In this review, a complete and updated list of more than 200 commercially available small-scale horizontal and vertical wind turbine models is provided and analysed, detailing the corresponding characteristics in terms of the number and material of blades, start-up wind speed, cut-in wind speed, cut-out wind speed, survival wind speed, maximum power, noise level, rotor diameter, turbine length, tower height, and specific capital cost. In addition, several scientific papers focusing on the experimental assessment of field performance of commercially available small-scale horizontal and vertical wind turbines have been reviewed and the corresponding measured data have been compared with the rated performance derived from the manufacturers’ datasheets in order to underline the discrepancies. This review represents an opportunity for the scientific community to have a clear and up-to-date picture of small-scale horizontal as well as vertical wind turbines on the market today, with a precise summary of their geometric, performance, and economic characteristics, which can enable a more accurate and informed choice of the wind turbine to be used depending on the application. It also describes the differences between theoretical and in-situ performance, emphasizing the need for further experimental research and highlighting the direction in which future studies should be directed for more efficient design and use of building-integrated small-scale wind turbines.

Molecular dynamics simulation of tensile properties of Nickel-based superalloy with temperature and Co

Ni(Nickel)-based superalloys are used as indispensable materials for turbine blades in aero-engines because of their excellent creep, fatigue and corrosion resistance. Co(Cobalt), as one of the new key elements in Ni-based superalloys, has attracted extensive attention in Ni-based superalloys field. However, the effect mechanism of Co on Ni-based superalloys is still controversial. To solve this problem, tensile properties and microstructure of Ni-based superalloys doped with or without Co (5 %) have been investigated through molecular dynamics simulation, and the joint impact of temperature and Co on the superalloy mechanical properties has also been analyzed. The findings indicate that 5 % Co doping reduces the yield stress, yield strain, and elastic modulus of the structure, while increasing the flow stress at 300 K–600 K; however, the advantage decreases at 900 K and disappears completely at 1200 K. This can be explained that Co doping leads to more slippage of stacking faults in the elastic stage and hinders the loop formation of dislocations at 300 K–600 K, while more Stair-rod dislocations occur in the plastic stage. These effects disappear at 900 K–1200 K.

Analysis of Shafting System Vibration Characteristics for Mixed-Flow Hydropower Units Considering Sand Wear on Turbine Blades

Addressing the issue of increased shaft-system vibration in high-altitude mixed-flow hydropower generating units due to sand wear on turbine blades, a three-dimensional model of a specific mixed-flow water turbine was constructed. CFD numerical simulations were employed to analyze the fluid exciting force acting on the turbine runner under varying degrees of blade wear. An approximate analytical model was then established for the variation of fluid exciting force in the turbine runner system using the Fourier harmonic analysis method. A multi-degree-of-freedom mathematical model of flexural and inclined coupling vibration of a hydropower unit’s shafting, considering blade wear, was constructed. The nonlinear dynamic model was numerically calculated by the Runge–Kutta method. The vibration responses of the shafting of hydropower units under different wear degrees were obtained by means of a time-domain diagram, frequency-domain diagram, axis-locus diagram, phase-locus diagram, and Poincare mapping. Based on the formula for calculating the wear amount of the blade material, the runner amplitude degradation trajectory model was established, and the pseudo-failure time of turbine blades was determined according to the allowable value of amplitude.

The Petiole of the Miriti Palm: A sustainable material for wind turbine blades?

The Miriti Palm (Mauritia flexuosa) grows abundantly in the Amazon Region of Brazil. The petiole (PMP) that supports the leaves, has a density of about one-half of Balsa wood (BW), which is used in the manufacture of wind turbine blades. A further possible advantage of PMP is that harvesting does not kill the palm tree, in contrast to the harvesting of BW. Because the mechanical properties of PMP have not been measured, we determined the shear and tensile properties of 16 samples of PMP and BW to allow a preliminary assessment of PMP as a possible material for blades. The absolute shear and tensile strengths for BW are higher, but specific properties (normalized by the density) are similar and can favour PMP. Direct substitution of BW by PMP would reduce the weight of a typical large blade by around 2%.

Experimental investigation of multi-step airfoils in low Reynolds numbers applications

This study provides a detailed analysis of the aerodynamic performance of various airfoil configurations, focusing on lift coefficient, stall characteristics, and maximum lift-to-drag ratio. The investigation includes the NACA23012C profile and configurations with different step geometries, ranging from one-step to five-step designs. Experimental measurements were conducted using a well-equipped aerodynamic laboratory, Institute of Aviation Engineering and Technology (IAET), Giza, Egypt. The lab features a wind tunnel, propeller test rig, and data acquisition system. The experiments were conducted meticulously to ensure accuracy and reproducibility, with a standardized method employed for uncertainty analysis. The results reveal distinct aerodynamic behaviors among the different configurations, highlighting the significant impact of design variations on aerodynamic performance. Notably, the three-step configuration consistently exhibited high performance, with a competitive or superior lift coefficient across a range of Reynolds numbers, showing an improvement of up to 35.1 %. Similarly, the four-step configuration demonstrated substantial increases in lift-to-drag ratios, reaching up to 53.2 %, while the five-step configuration exhibited varying trends with a minimum drag coefficient. The study also investigated stall characteristics and sensitivity to Reynolds numbers, revealing the complex trade-offs inherent in airfoil design. The findings provide valuable insights into optimizing airfoil performance under different operational conditions. Additionally, the adoption of two and three stepped airfoils resulted in significant reductions in blade material and associated costs for turbine blades.

Multi-objective optimization of glass/carbon hybrid composites for small wind turbine blades using extreme mixture design response surface methodology

Small wind turbines (SWTs) are a prominent renewable energy technology for decentralized power generation. Blade material and its profile are vital parameters for the aerodynamic performance of SWTs. Traditionally E-glass fiber-reinforced composites (FRCs) are the widely accepted material for developing SWT blades. However, its application is limited by moderate tensile and fatigue properties. Alternatively, other FRC materials such as carbon, basalt and natural fiber composites are proposed as future materials for SWT blades. However, individual materials are observed to satisfy the requirements partially. Therefore, the hybridization of these materials, particularly Glass/Carbon composites is foreseen as a prospective solution for developing cost-competitive and high-strength SWT blades. There are various studies performed to obtain optimized glass/carbon hybrid composites. However, overall material properties required for SWT blades such as low cost, lightweight, moderate flexural strength and higher tensile and fatigue strengths have not been considered simultaneously during the optimization process. This work presents multi-objective optimization of Glass/Carbon hybrid composites using extreme mixture design response surface methodology (RSM) for SWT applications. The weight percentages of glass and carbon fibers are optimized to achieve desired material properties for SWT blades. The experiments are planned using extreme mixture design RSM and the regression models for desired material properties are developed with a 95% confidence level. RSM-based desirability function is employed to perform multi-objective optimization. Maximum composite desirability of 93.5% is achieved with optimal proportions of 37.9% and 27.1% for glass and carbon fibers respectively. An adequate tensile, flexural and fatigue strengths of 486.02, 435.41 and 316.27 MPa respectively are obtained for optimized glass/carbon hybrid composite at an optimum cost of 2228.76 Rs Kg−1 and density of 3.39 g cm−3. The regression models and optimization results are validated through a confirmation experiment with an error of less than 6.1%.

Performance Enhancement in Submersible Pump Impellers: Design and Optimization Approaches

Abstract: Submersible pumps are essential components in various industries, including water supply, wastewater management, and oil extraction. Their efficiency and reliability are crucial for ensuring consistent fluid transport. At the core of submersible pumps lies the impeller, which directly influences pump performance. This paper examines advanced design and optimization approaches to enhance the performance of submersible pump impellers. By analyzing key factors such as blade geometry, material selection, and impeller design parameters, we explore methods to improve hydraulic performance, energy efficiency, and operational stability. Experimental validation confirms the effectiveness of these approaches in achieving superior pump efficiency and longevity. This study contributes to the advancement of submersible pump technology and sets a foundation for future research in the field.

Fatigue Damage Assessment of Turbine Runner Blades Considering Sediment Wear

The wear phenomenon that occurs on the blades during operation has a significant impact on the fatigue life of the blades. To address the issue of fatigue life assessment for turbine runner blades subjected to increased dynamic stress due to sediment wear, taking a specific high-head hydropower unit’s mixed-flow turbine as the research subject, a hydraulic model of the turbine was established. The wear zones of the runner blades are determined based on the distribution of the flow field’s velocity and the sediment volume fraction. According to the wear rate formula for runner blade material, the amount of wear on the blades is determined, and the dynamic stress data for the dangerous areas of the blades under different degrees of wear are calculated using a unidirectional fluid–structure coupling method. The load spectrum of the time–stress history data for the dangerous area at different levels of wear was compiled using the rain-flow counting statistical method. The operating time ratios for the flood season and the non-flood season are combined. Based on the fatigue cumulative damage theory, the total fatigue damage at the maximum stress part of the runner blade was calculated for different stages of wear, providing a reference for the life calculation of mixed-flow hydraulic turbines.

Modeling of particle erosion of high-pressure turbine based on dynamic mesh method

In this work, we investigate erosion characteristics of a high-pressure turbine by using Oka erosion model coupled with the dynamic mesh method, which allows for the dynamic change of blade profile. The variation of blade profile, material removal and performance degradation during erosion are quantified for the original blade, and the results are compared with those of an optimized blade previously obtained through multi-objective optimization of aerodynamic and erosion resistance performances. It is found that compared with the original blade, the optimized blade is of higher efficiency and lower erosion, suggesting that the previous multi-objective optimization, albeit ignoring the dynamic change of blade profile, still works for the dynamic erosion process. For either blade, the efficiency decreases slowly at first and drops sharply after a period of erosion, because as the erosion proceeds, the regions occupied by the vortex rapidly expand, leading to the blockage of blade passage. The transient erosion characteristics and particle trajectories indicate that the erosion is initially located near the middle and rear of blade on pressure side and the leading edge on suction side; as the erosion progresses, the erosion mainly occurs near the leading edge on pressure side but almost disappears on suction side.

Study of phase equilibrium of refractory high-entropy alloys using the atomic size difference concept for turbine blade applications

Abstract In the pursuit of advancing turbine blade materials, refractory high-entropy alloys (RHEAs) have emerged as promising candidates, offering superior performance at elevated temperatures compared to conventional superalloys. With the plateauing of melting temperatures in Ni-based superalloys, the demand for innovative material systems capable of substantial performance enhancements in turbines has increased. The expansive compositional space of high-entropy alloys (HEAs) presents a rich yet underexplored realm, particularly concerning the intricate phase equilibria pivotal for alloy stability at high temperatures. This research purpose is to elucidate the phase formation dynamics within the W–Re–Ni–Co–Mo HEA system across varying atomic percentages of each constituent element. Employing two-dimensional mapping methodology for correlating atomic size difference and enthalpy mix parameters, enabling the differentiation between intermetallic (IM) phase and single-phase formations in the non-equimolar W–Re–Ni–Co–Mo system across numerous atomic percentages of each element. Major findings indicate distinct phase formations based on elemental compositions, with elevated nickel and rhenium percentages favouring single-phase solid solution (SPSS) structures, while diminished concentrations yield alternative configurations such as (IM + SPSS). Similarly, variations in tungsten and molybdenum concentrations influence phase stability. The ability to assess phases for diverse atomic percentages of elements in the W–Re–Ni–Co–Mo system will facilitate to analyse HEA systems for high-temperature turbine blades.

Enhancing energy conservation in power generation in a coal fired thermal power plant through comprehensive energy audit

Current work presents salient insights from energy audit of a 1050 MW thermal power plant by BEE Certified Energy Auditors. It provides insights into grassroot level data instead of relying only on theoretical calculations, unlike previously published literature.Arresting the air leakages in air-preheater has given total saving of 10.72 million kWh/year, saved 398,978.97 kJ/year, thus saving of 25,322.80 MT of coal/year. Upgradation of insulation resulted in total saving of 6632.208 Million kJ/year, i.e. saving of 510 MT/year of coal. Replacing cooling tower blades material proposed saving of 15,242.4 kWh/year. Installation of Variable Speed Drives for pumps provided saving of 274,836 kWh/year. Replacement of old inefficient pumps with energy efficient pumps has saving potential of 739,632 kWh/year. Pressure reduction in compressors has given saving of 344,794 kWh/year.Thus, in total, this energy audit helped to conserve 12.098 Million kWh & 25,832.80 MT coal/year and consequently, 104,243 tCO2/year. Such savings not only help the plant management/decision makers on the monetary front but also identify the avenues for improvement and channelize the resources such time and investment, prudently. Consequently, it has been established that energy audit is a pragmatic tool to achieve energy conservation at grassroot level.

Nanotechnology's potential in advancing renewable energy solutions

Nanotechnology has emerged as a promising frontier in the quest for sustainable energy solutions, offering transformative opportunities to address pressing challenges in renewable energy generation, storage, and conversion. This review explores the potential of nanotechnology in advancing renewable energy solutions, encompassing a wide range of applications spanning solar energy, wind energy, energy storage, and fuel cells. By leveraging the unique properties of nanomaterials, such as high surface area-to-volume ratio, tunable optical and electronic properties, and enhanced catalytic activity, researchers and engineers can develop innovative materials and devices with unprecedented performance and efficiency. Nanotechnology-enabled advancements in solar photovoltaics include the development of next-generation solar cells incorporating nanostructured materials, such as quantum dots, nanowires, and perovskite-based solar cells, to enhance light absorption, charge transport, and overall power conversion efficiency. In the realm of energy storage, nanomaterials hold promise for improving the performance and longevity of batteries, supercapacitors, and other energy storage devices through enhanced electrode materials, electrolytes, and nanostructured architectures. Furthermore, nanotechnology-driven innovations in wind energy, such as lightweight and durable nanocomposite materials for turbine blades, and advancements in fuel cell technologies, including catalyst nanoparticles for efficient hydrogen production and conversion, exemplify the diverse applications and transformative potential of nanotechnology in renewable energy. Through a comprehensive analysis of recent research and development efforts, this abstract underscores the critical role of nanotechnology in accelerating the transition to a sustainable and renewable energy future. Keywords: Nanotechnology, Renewable Energy, Solar Energy, Wind Energy, Energy Storage, Nanomaterials.

Influence of Surface Roughness on Symmetric Airfoil Flow Properties and Reynolds Number

Collaborative Aircraft Design Optimization: Investigating Roughness Management of Wings to Reduce Drag and Improve Performance This study investigates the potential of roughness control of aircraft wings based on joint design optimization. By adding roughness points to specific wings, our goal is to reduce drag and improve the overall performance of the aircraft. A multi-modal design optimization (MDO) framework combining aerodynamics, modelling, and performance analysis was used in this study. We measure the effect of tissue on the boundary layer, the progression of laminar flow, and the potential for weight savings due to reduced friction. This study investigates how roughness control interacts with other design factors such as flow components or blade materials to achieve optimal performance. The ultimate goal is to create a collaborative design that uses tissue management to contribute to next-generation fuel efficiency and high performance. Keywords – CFD, Surface Roughness, Wind Tunnel, Aerodynamic Efficiency.

Characterisation of Polyurethane-urea as Leading-Edge Erosion Resistant Materials of Wind Turbine Blades

Surrounded by oceans, building offshore wind turbines is a great strategy for archipelago countries, like Indonesia, to harvest renewable energy from wind. However, because of high rainfall rate, water droplet erosion on wind turbine blades is inevitably to be one of the most challenging problems. It causes decreasing produced energy and increasing cost of maintenance and repairment. A novel coating material which has better mechanical properties is therefore required. As a preliminary step, this work aims to characterise thermal and mechanical properties of soft and hard polyurethane-urea (PUU). In this work, the materials are soft PUU30 which has a hardness of 30 shore A, and hard PUU95 which has a hardness of 95 shore A. Thermal properties are characterised by Differential Scanning Calorimetry (DSC), while mechanical properties are investigated by tensile test at various strain rates. The results show that PUU95 has a higher strain rate dependence on modulus, tensile strength, and strain at break, which need to be considered for application regarding the range of wind speeds.

Experimental investigation of cutting force of powder metallurgy valve guide rod hole

Aiming at the problem of fast wear of machining tools in the special powder metallurgy valve guide rod hole and gasket seat of a certain engine cylinder head, in order to solve the technical problems in the cutting force (CF) of this kind of powder metallurgy materials, different tools are used and the analysis is carried out under different cutting test conditions. The cutting force law and surface roughness change law of similar powder metallurgy materials are determined to determine the appropriate tool materials and processing parameters. The experimental results show that under the same processing conditions, ceramic tools will suffer less than cemented carbide tools and cutting force can obtain a smaller surface roughness. In addition, the mass production process of valve seat, the blade material is ceramic knife.

Effect of blade materials on the undershot water turbine performance

Undershot waterwheel at low flow with an average discharge of 0.12 m3/s and 613.2 W water horsepower are used to turn the waterwheel. The rotation results obtained with aluminum material is 24 RPM which has a density of 2.71 g/cm3 while the lowest rotation is owned by a galvanic of 20 RPM with a density of 7.49 g/cm3. From the experiment, it was found that the difference between the materials used was due to the different density. The efficiency of waterwheels with aluminum material has the highest value, namely 30%, while the lowest using acrylic material has an efficiency of 23%. For the highest generator efficiency using aluminum material with an efficiency of 4.2%, the second has an efficiency of 3.6% using Aluminum Composite Panel material. Aluminum has the highest efficiency because it has less density than galvanized. In addition, the thickness of aluminum is also very influential, where aluminum has a thickness of 1.14 mm while Galvanized has 0.98 mm.

Application of ultrasonic fatigue technology in very-high-cycle fatigue testing of aviation gas turbine engine blade materials: A review

Application of ultrasonic fatigue technology in very-high-cycle fatigue testing of aviation gas turbine engine blade materials: A review

Experimental Study and Creep-Fatigue Life Prediction of Turbine Blade Material DZ125 Considering the Nonholding Effect and Coupling Effect of Stress and High Temperature

Abstract In response to the problem of creep-fatigue interaction damage failure of aero-engine turbine blade material, based on the modified damage evolution model of Kachanov-Rabotnov and Chaboche, a creep-fatigue life prediction model for nickel-based superalloy DZ125 is constructed considering the nonholding effect and coupling effect of stress and high temperature with the nonlinear interaction and superposition of creep damage and fatigue damage according to the continuum damage mechanics theory. Simultaneously, the microfracture morphology of DZ125 was analyzed using a scanning electron microscope, revealing the micromechanism of creep-fatigue interaction. The research results manifest that the creep-fatigue life prediction model has a high life prediction ability within ±2.0 times the dispersion band of the prediction results. Concurrently, a large number of intertwined tearing edges, microcracks, and microvoids appear in the fracture morphology, and creep and fatigue interact with each other in the form of effective stress. The above research can provide theoretical support for predicting the lifespan of mechanical structures in a high-temperature environment.

Characterisation of the creep cavitation process on grain boundaries in a polycrystalline nickel-base alloy 247

ABSTRACT Hot gas components such as gas turbine blades are loaded with constant centrifugal stress at high temperatures and thus the formation of creep cavitation on grain boundaries is expedited. Conventionally cast polycrystalline Nickel-base superalloys used as blade materials are prone to creep cavitation as unfavourably orientated grain boundaries exist. This research presents a diffusion-based probabilistic creep model which describes the creep cavitation process on grain boundaries. It includes the three mechanisms: pore nucleation, growth, and coalescence. The calibration of the model has been carried out by analysing Alloy 247 as-received specimens and specimens with pre-strain. For the evaluation of the pore numbers and sizes, a deep learning model for pore detection was trained on light microscopic and scanning electron microscopy images. Electron backscatter diffraction images are analysed for further investigations regarding grain orientations and grain boundary angles to the loading direction. The calibrated model allows predictions of pore size distributions over time.

Co-processing of end-of-life wind turbine blades in portland cement production

The objective of this paper is to evaluate the feasibility of co-processing wind turbine blade (WTB) material in cement manufacturing to provide an end-of-life means to divert the solid waste of decommissioned WTBs from landfills. Many WTBs consist primarily of glass fiber reinforced thermoset polymers that are difficult to recover or recycle. Portland cement is produced world-wide in large quantities, requiring immense quantities of raw materials (mostly calcium oxide and silicon oxide) and kiln temperatures approaching 1,450 °C. This work contributes analyses of WTB material composition, and predicts the energy provided through the combustible components of the WTBs and raw material contributions provided by incorporating the incombustible components of the WTBs to produce cement. Approximately 40 to 50 % of the WTB material will contribute as fuel to cement production, and approximately 50 to 60 % of the WTB material is expected to be incombustible. One tonne of WTB material can displace approximately 0.4 to 0.5 tonne of coal, while also contributing approximately 0.1 tonne of calcium oxide and 0.3 tonne of silicon oxide as raw material to the cement production process. The glass fiber WTB tested had an average boron content of 4.5 % in the ash. The effects of this high boron content on the cement and its production process should be evaluated. Co-processing WTBs in cement plants will slightly reduce combustion-related CO2 emissions due to avoided calcination. It seems feasible to co-process glass-fiber reinforced WTBs in cement production as WTBs provide suitable raw materials and compatible fuel for this process.