Turbine Rotor Research Articles

High Data Rate MWD Mud Pulse Telemetry – From Mysteries to Discovery

Our new approach to MWD mud pulse telemetry offers significant increases over conventional data rates. Using waveguide acoustics, we show that common drilling communications channels support carrier frequencies exceeding several hundred Hertz. Such signals are prone to attenuation over large drillpipe distances. Low power, self-spinning “turbosirens” are designed, providing high torque and rotation rate performance at all flow rates without electric or hydraulic motor drives. The sirens rotate, drawing only on the kinetic energy of the mud, like flapping flags oscillating in wind. Our turbosirens are minimally affected by LCM jamming. Turbine and siren rotor components ride freely along longitudinal trenches built into rotating shafts. Both magically float into the oncoming mud as it slows down, thus, widening all gap spaces and freeing any trapped debris even as both travel opposite to the mud flow. In addition, “turbosirens in series” signal superposition, drawing on constructive wave interference, offers strong pressure signals at high frequencies without mechanical complexity. Rapid modulations are possible, also without motor drive, relying on rapidly acting electro-magneto rheological brakes powered by turbosirens. To take advantage of hardware capabilities, “Intelligent i FSK” telemetry, or Frequency Shift Keying creates clean signals without the ambiguous wave reflections found with PSK and randomized time shifts. Frequency pairs are not selected arbitrarily, but chosen from “neighboring pressure peaks and valleys” in frequency space as determined from bottomhole assembly waveguide Fourier analysis. Finally, surface signal processing and reflection removal are facilitated with time delay and differential equation algorithms. For deep wells where multiple drill pipe reflections are unlikely, analytical solutions for both are obtained assuming single reflections which do not involve windowing challenges and complicated digital filter design. Software and hardware developments patented, published and validated over the years, are integrated, refined and readied for controlled field tests.

A Study on Wind Collection Effect of Vertical Axis Windmills

In recent years, global warming caused by greenhouse gasses such as carbon dioxide has become a concern. This has resulted in increased focus on environmentally friendly power systems. Consequently, renewable energy power generation methods, such as wind and solar power generation, have attracted attention. Wind power generation is expected to significantly increase in the future. However, in many inland areas in Japan, the average wind speed remains 6 m/s or less. In this study, we proposed the introduction of winglets and wind collectors (used in aircraft wings) into straight-wing vertical-axis wind turbines to improve their power generation efficiency. Field tests were conducted to confirm the effectiveness of the proposed method. Using winglets and wind collectors, the wind turbine rotation speed was increased at low wind speeds, which facilitated the generation of power. Moreover, it was confirmed that a wind turbine equipped with the proposed winglets and wind collectors could capture wind without its dispersal as it passed through the turbine.

Development of Savonius Type Wind Turbine Model as A Source of Renewable Electrical Energy

Abstract Wind turbines can be used as a renewable energy resource, especially in remote areas and outer islands where there is no electricity. Based on the calculations that have been carried out, it is found that the dimensions of the wind turbine model used in this research are a turbine height of 1 meter with a diameter of 0.5 meters. Meanwhile, the dimensions of the shaft used are 20mm. Model testing has been carried out in Juanda Surabaya, it is known that the generator power produced increases along with increasing wind speed which is also influenced by the rotation of the wind turbine. In the results of this research, the largest generator power was produced at a wind speed of 4.8 ms−1, which produced a generator power of 12.6 watts. Meanwhile, the lowest power is 0 watts because a wind speed of 0.4 m/s is not able to rotate the wind turbine. From the data collection results, it was also found that the SCC could only charge the battery if the minimum voltage reached 13 volts. So the new SCC can charge the battery at a wind speed of 3.7 m/s with a voltage output of 13.1 volts and a current strength of 0.5 amperes. This research will use a Savonius wind turbine with 2 rotor blades with dimensions of 1 meter high and 0.5 meter diameter. The research results show that power is obtained at a generator voltage starting from 13.1 volts which produces a current strength of 0.7 amperes. It is at this voltage that the new Solar/Wind Charge Control can charge the battery.

Retraction Note: A review on comparative study of Savonius wind turbine rotor performance parameters.

Retraction Note: A review on comparative study of Savonius wind turbine rotor performance parameters.

Effect of heterogenization on the microstructure evolution and high temperature deformation behaviour of a nickel base superalloy

Medium alloyed nickel-based superalloy DMR SN 742 is widely used as high-pressure compressor (HPC) and turbine (HPT) rotors in various aeroengines. Establishing innovative processing schemes is essential to improve the workability of this difficult-to-deform material. A combination of heterogenization and high temperature deformation has been employed in this study to address this issue. Heterogenization is intended to coarsen the gamma prime (γ′) phase present in the material while the deformation is intended to refine the size of gamma matrix. A combination of the aforementioned processes is expected to assist in producing fine grained equiaxed duplex microstructure comprising of gamma prime (γ′) and gamma (γ) that exhibits better workability. In order to identify and establish suitable heterogenization scheme for DMR SN 742, sub-solvus and super-solvus heterogenization was carried out by imposing a controlled cooling rate of 10 °C/hr after high temperature exposure. Detailed microstructural evaluation carried out on material subjected to heterogenization revealed multimodal distribution of γ′ precipitate within the parent gamma matrix. The coarsening of γ′ precipitates was observed to be significantly higher for super-solvus heterogenization when compared to sub-solvus heterogenization. Further, the high temperature deformation behaviour of sub and super solvus heterogenized material was investigated by carrying out isothermal hot compression test at 1000 °C with a constant true strain rate of 10−3 and 10−1/s. Heterogenized material was found to exhibit better workability when compared to the as-received material. Further, super solvus heterogenized material exhibited a relatively less flow stress, higher flow softening and higher discontinuous dynamic recrystallized grain fraction. A combination of super solvus heterogenization followed by deformation at 1000 °C with a strain rate of 10−1/sec can be used to coarsen the γ′ precipitate (primary: 1.2± 0.4 μm, secondary: 0.66 ± 0.19μm) and refine the size of gamma matrix (1–1.5μm) in nickel based superalloy DMR SN 742.

Failure and Risk Analysis of Aeroengine Turbine Rotor Blade Fractured Due to Arch Binding

Failure and Risk Analysis of Aeroengine Turbine Rotor Blade Fractured Due to Arch Binding

Precision compensation method for large-scale measurements based on full-space refractive index field reconstruction with vibratory mirror background oriented schlieren (VMBOS)

With the development of the large-scale equipment manufacturing industry, such as aircraft component assembly, wind turbine rotor blade measurement and large ship assembly the demand for optical measurement accuracy in large-dimensional spaces within industrial environments has become increasingly stringent. However, due to the presence of internal interference sources, light will no longer propagate in a straight line, thereby introducing measurement errors that cannot be ignored. To compensate for the measurement error, the refractive index field distribution within the large-dimensional measurement space must be reconstructed. Therefore, this paper proposed a vibratory mirror background oriented schlieren (VMBOS) based on vibratory scanning. This method scans the measurement space through the rotation of vibratory mirror to obtain light deflection angles at different directions. Subsequently, the refractive index field of the large-dimensional space is reconstructed by using the tomographic reconstruction algorithm. Then the optical path of the light in the optical measurement can be corrected through the Hamiltonian ray tracing algorithm, thereby achieving compensation for the measurement error. Finally, the VMBOS method has been verified through both simulation and experimental methods. The experimental results demonstrated that the method proposed in this paper can be applied to optical path correction and error compensation in large scale spaces.

Electromagnetic–thermal–mechanical coupling analysis of bent rotor straightening via electromagnetic induction heating

Abstract Rotors of steam turbines in power plants can be locally deformed by undesired situations, such as rubbing between the rotors and stationary parts. A straightening process is required to correct bending without causing additional damage because a rotor bending displacement of approximately 0.15 mm can stop turbine unit operation. In this study, a numerical framework was established to simulate the straightening process using electromagnetic induction heating, which is straightforward and economical among the methods for straightening bent rotors. The straightening process involves complex coupling of electromagnetic, thermal, and mechanical phenomena. For efficiency, sequential coupling was used in the simulations, dividing the multiphysics phenomena into electromagnetic–thermal and thermal–mechanical fields. The temperature distributions resulting from electromagnetic induction heating were calculated through two-way coupling of the electromagnetic–thermal analysis. The thermal deformations of the rotors were obtained by solving the coupled equations for the thermal field obtained from the electromagnetic–thermal analysis and the mechanical field. Using the established numerical framework, the thermal–mechanical behaviors and straightening mechanisms of bent rotors were investigated. Furthermore, the effects of process parameters, including the direction of gravity and heating and cooling conditions, on the straightening performance were determined. Appropriate parameters were identified to achieve the desired straightening performance with final bending displacements of less than 0.1 mm for bent rotors with initial bending displacements of 0.15–0.3 mm. For a rotor made of A182 F11 Class 2, the best straightening performance was obtained by heating the rotor to a maximum temperature of 650 °C for 20 h under insulation, followed by natural cooling. The simulation results revealed that the straightening performance can be improved when the rotor is rapidly heated to a high maximum temperature and cooled immediately, as long as the temperature conditions do not cause phase transformation or unintended plastic deformation of the bent rotors.

Method for Helicopter Turboshaft Engines Controlling Energy Characteristics Through Regulating Free Turbine Rotor Speed and Fuel Consumption Based on Neural Networks

This research is devoted to the development of a method for helicopter turboshaft engine energy characteristics control by regulating the free turbine rotor speed and fuel consumption using neural network technologies. A mathematical model was created that links the main rotor and free turbine rotor speed parameters, based on which a relation with the engine output power was established. In this research, a differential equation was obtained that links fuel consumption, output power, and rotor speed, which makes it possible to monitor engine dynamics in various operating modes. A fuel consumption controller was developed based on a neuro-fuzzy network that processes input data, including the desired and current rotor speed, which allows real-time adjustments to improve the operational efficiency. In the research, based on the flight data analysis obtained during the Mi-8MTV helicopter with a TV3-117 turboshaft engine flight test, improved signal processing quality was obtained due to time sampling and adaptive quantisation methods (this is confirmed by assessing the homogeneity and representativeness of the training and test datasets). A comparative analysis of the developed and traditional controllers showed that the neuro-fuzzy network use reduces the transient fuel consumption process time by 8.92% while increasing the accuracy and F1 score by 18.28% and 21.32%, respectively.

COMPUTATIONAL AND EXPERIMENTAL IMPACT STUDY INITIAL PAIRING PARAMETER OF BANDAGE SHELVES PAIRS OF BANDED BLADES FOR STATIC STRESSES IN THE FEATHER OF THE SHOULDER BLADES

The paper discusses the results of an experimental study of the influence of the initial parameter of the conjugation of the bandage flanges on static stresses in the blade feather, as well as a comparison of the results obtained with the calculated data. The work was carried out for both uncooled and cooled turbine rotor blades. It was found that with an increase in the initial conjugation parameter, the static stresses in the root section of the blades increase in direct proportion. It was found that the static stresses in the feather for the left and right blades are almost the same with the same conjugation parameter, both for non-cooled blades and for cooled blades. There is a significant error between the experimental and calculated values, while the nature of the dependence of stresses on the initial parameter is similar – rectilinear.

Architecting a digital twin for wind turbine rotor blade aerodynamic monitoring

Digital twins play an ever-increasing role in maximising the value of measurement and synthetic data by providing real-time monitoring of physical systems, integrating predictive models and creating actionable insights. This paper presents the development and implementation of the Aerosense digital twin for aerodynamic monitoring of wind turbine rotor blades. Employing low-cost, easy-to-install microelectromechanical (MEMS) sensors, the Aerosense system collects aerodynamic and acoustic data from rotor blades. This data is analysed through a cloud-based system that enables real-time analytics and predictive modelling. Our methodological approach frames digital twin development as a systems engineering problem and utilises design patterns, design thinking, and a co-design framework from applied category theory to aid in the development process. The paper details the architecture, deployment, and validation of a ‘Digital Shadow’-type twin with simulation/prediction functionalities. The solution pattern is discussed in terms of its implementation challenges and broader applicability. By providing a practical solution to integrating all the digital twin components into a holistic system, we aim to help wind energy specialists learn how to transform a conceptual idea of a digital twin into a functional implementation for any application.

Performance enhancement of horizontal axis wind turbine with guide ring

This study investigates the impact of integrating a guide ring upstream of the rotor plane for performance increase of a horizontal axis wind turbine rotor. The guide ring is strategically positioned near the rotor hub to reduce the radial component of wind flow and retain more axial velocity through the rotor. The methodology involved physical testing of a rotor retrofitted with guide rings ranging from 15% to 20% of the rotor diameter. Comparative experimental results demonstrate an increase in peak performance for retrofitted rotors, when compared to a standard rotor. The rotor retrofitted with an 18% guide ring emerged as the most beneficial choice, exhibiting a 4.34% peak power output increase and a broader operational range than the standard rotor. Overall, the study contributes valuable insights into post-installation optimisation strategies for horizontal axis wind turbine rotors.

Infrared Thermography of Turbulence Patterns of Operational Wind Turbine Rotor Blades Supported With High‐Resolution Photography: KI‐VISIR Dataset

ABSTRACTWith increasing wind energy capacity and installation of wind turbines, new inspection techniques are being explored to examine wind turbine rotor blades, especially during operation. A common result of surface damage phenomena (such as leading edge erosion) is the premature transition of laminar to turbulent flow on the surface of rotor blades. In the KI‐VISIR (Künstliche Intelligenz Visuell und Infrarot Thermografie—Artificial Intelligence‐Visual and Infrared Thermography) project, infrared thermography is used as an inspection tool to capture so‐called thermal turbulence patterns (TTPs) that result from such surface contamination or damage. To complement the thermographic inspections, high‐resolution photography is performed to visualise, in detail, the sites where these turbulence patterns initiate. A convolutional neural network (CNN) was developed and used to detect and localise turbulence patterns. A unique dataset combining the thermograms and visual images of operational wind turbine rotor blades has been provided, along with the simplified annotations for the turbulence patterns. Additional tools are available to allow users to use the data requiring only basic Python programming skills.

Toughening of thick bonded interfaces through architected crack-arresting features

This research investigates the application of additively manufactured crack-arresting features (CAFs), designed from tough and soft polymers, in enhancing the performance of thick glass fiber-reinforced polymer composite-epoxy adhesive joints found in wind turbine rotor blades. Mode I fracture and fatigue behaviors of these joints are assessed through double-cantilever beam experiments and compared against pristine joints. In pristine joints, cracks consistently deviate from the adhesive bondline into the composite adherend, causing a sudden increase in strain energy release rate. Finite element models based on linear elastic fracture mechanics are employed to provide insight into this behavior. Experimental results demonstrate that joints with architected CAFs achieved higher strain energy release rates, more stable failure mechanisms, and minimized damage to the composite adherend. Under fatigue loading, joints featuring tough CAF material exhibit slower fatigue crack growth compared to both pristine joints and those with soft CAF material.

Damage to Steam Turbine Rotors Due to Asynchronous Connections of Electric Generators to the Unified Power System

The article aims to contribute to the ongoing study of damage to steam turbine rotors resulting from asynchronous connection of electric generators to the unified power system. At the present time, the assessment of the residual life of steam turbine equipment is based on the study of the degradation of the mechanical properties of steels and the analysis of the thermal stress state. The aim of this work was to determine the impact of such vibrations on the mechanical properties of rotors and their damage. This goal was achieved by solving the following tasks: developing a 3D model of the K-1000-60/3000 LMZ turbine unit shaft based on design documentation; calculating the stress-strain state of the shaft resulting from asynchronous connections using finite element analysis; and evaluating the level of metal damage in the rotors due to torsional vibrations. The developed mathematical model used a classical approach, replacing the working blades and bandage fastenings with concentrated masses and moments of inertia. The most important results are the calculated rotor damages that occur due to asynchronous connection of the turbogenerator to the unified power system with a synchronization angle of 30°. The greatest damage to the rotor metal was found in the shaft section between the steam turbine and the electric generator. The significance of the results obtained is that the use of this data will improve meth-ods for assessing the remaining life of turbogenerators. This, in turn, will improve the reliability and safety of power plant operations.

Dynamic Formulation of the Double Multiple Stream Tube Model of Offshore Vertical Axis Wind Turbines

Abstract The paper proposes a novel algorithm to simulate Vertical Axis Wind Turbines in floating motion based on a low-fidelity approach. The conventional Double Multiple Stream Tube Model is formulated as a steady state model to deal with the inherent unsteady aerodynamics of VAWTs. The Double Multiple Stream Tube Model makes use of an average contribution of the blade passages over a revolution to solve the Blade Element Momentum equation. The model reduces the dependence of the solution (the induction field) to a space variable. Floating Vertical Axis Wind Turbines undergoes a variation of aerodynamic quantities according to wave periods, also different from the rotor period. This paper provides a new formulation of the Double Multiple Stream Tube Model to solve the turbine rotation in time and space, introducing the variation of the platform velocity and a revised approach to the downstream actuator disc. The most impactful parameter is found to be the wave frequency: wave periods at full-scale are lower than the ones of the turbine rotor, featuring optimal operating points at low tip speed ratios. The increase of the wave frequency highlights the differences of the average torque prediction for a single blade up to 10% between the unsteady and the standard formulation. In this context, the development of fast low-fidelity computational tools play a key role in the assessment of the preliminary designs of Floating Offshore Vertical Axis Wind Turbines and it will be used to optimise the aerodynamic design of the laboratory scaled model under surge motion.

Hybrid Testing System Development for Single Point Mooring Lines FOWT’s

Abstract To advance the development of various concepts for floating offshore wind turbines, it is imperative to have access to experimental data. These data are used in the validation of the tools for the simulation of floating turbines and also for the tuning of the models. CENER has developed a hybrid testing methodology that enhances the performance of wave basin tests for scaled models of Floating Offshore Wind Turbines (FOWTs). This approach allows us to apply forces and moments from the wind turbine to the floating platform without needing to replicate wind within the testing facility or create a complex model of the wind turbine rotor. However, when it comes to testing single point moored (SPM) platforms, a unique challenge arises. These platforms have an additional degree of freedom as they can freely rotate around the vertical axis of their mooring attachment (yaw degree of freedom). These type of platforms can present important misalignments with respect to the wind depending on the combination of wind, wave and current directions. Consequently, accurately capturing the impact of misalignment on platform dynamics, especially in yaw, is essential to assess the platform’s ability to self-align with the wind direction, a key factor known as weathervaning capacity. The X1Wind platform is an innovative floating wind system, based on a single point mooring solution with a downwind wind turbine configuration that allows it to be passively self-orientated. The concept has been extensively tested on prototypes at real sea conditions as well as on scaled models at wave basins. For the last wave basin testing campaign, X1Wind has entrusted CENER with the development of the hybrid testing methodology adapted to the requirements of SPM platforms. The testing campaign has covered different wave and wind conditions, including misalignment scenarios and has shown a good dynamic behavior of the platform on yaw. This study outlines the advancements made in the CENER Software-in-the-Loop (SiL) hybrid testing system for wave basin tests of SPM platforms. In order to correctly introduce the direction of the aerodynamic forces on the wind turbine under misaligned conditions, improvements on the software and hardware (loads actuator) of the SiL system were developed and tested. An actuator system consisting of 6 propellers was used. The numerical model that calculates the rotor aerodynamic loading were expanded to take into consideration the direction of the aerodynamic loads with respect to the platform. Additionally, the drag of the wind over the tower and other platform elements must be considered, as they can play a relevant role in the generation of the weathervaning moment. The study concludes that the use of the upgraded SiL hybrid testing system is an effective and afordable solution for the testing of scaled SPM platforms at wave basin facilities. It also summarizes the different considerations that the system has to overcome for the particularity of this type of testing application.

Preventing scour of monopile foundations using a vertical rotation device

Scour around monopile foundations is a major cause of offshore wind turbine failures, necessitating effective scour prevention measures to ensure the reliability of monopiles. This study investigates a new scour prevention strategy utilizing a vertical turbine rotor. This measure can not only effectively reduce scour around monopile foundations in complex flow field environments but also generate clean electricity, adding value. The effectiveness of the device in mitigating scour is evaluated through experiments. Subsequently, the impact of the flow field around the pile foundation and the seabed shear stress are examined using numerical simulations. The influence of the device’s installation position on seabed shear stress is also discussed. The results indicate that the vertical rotating device significantly reduce scour around the pile foundation, thereby enhancing the reliability of monopile foundations.

Optimization of Tip Seal Grooves for Aerodynamic and Durability Improvements of Small-Core Turbines

Abstract While the gap between the turbine rotor tip and the outer case in a gas turbine engine is necessary for engine function, the gap is kept as small as possible due to the detrimental effect of the flow over the turbine tip. With the increased investments in ultra-high bypass turbofans, blade tip clearances are increasing in relative size to the turbine rotor, as engines move towards smaller cores. In this work, an optimization of a rotor tip seal with discrete axisymmetric grooves was explored computationally using RANS simulations. The optimization was applied at two tip clearances representing a nominal and small-core-scaled geometry, and with both flat- and squealer-tipped blades. The multi-objective optimization was designed to maximize rotor efficiency and minimize tip heat load. Several casing designs were identified for each tip configuration that both increased efficiency and reduced the heat load into the rotor tip. However, some optimal tip seal designs were composed of grooves that were demonstrated to be detrimental in prior work. Furthermore, grooves were more effective at increasing efficiency when applied to flat tipped geometries – increasing efficiency by 0.9 points over the ungrooved baseline with flat tipped blades, as opposed to 0.25 points over the ungrooved case with squealer tipped blades. Finally, optimal seal geometries that were obtained from the small-core scaled clearance gap optimizations maintained near optimal performance when evaluated at the design tip clearance, while those geometries developed at the design clearance experienced greater tip gap sensitivity.

Modeling and Performance Analysis of Variable Cycle Engine with Ceramic Matrix Composite Turbine Blades

To meet the requirements of future aircraft for power systems, the turbine inlet temperatures of aero engines are gradually increasing. Ceramic matrix composite (CMC), with its higher thermal limit, has become the preferred material for the turbine blades of variable cycle engines (VCEs). However, the impact of CMC turbine blades on the performance of a VCE is still unknown. In this research project, the comprehensive cooling-efficiency characteristics of CMC are determined through a fluid–solid coupling calculation; a cooling calculation model for turbine blades is established, and cooling airflow solution and control technology (CSCT) for an air system is developed. Additionally, a VCE simulation model is established to analyze the influence of CMC turbine blades on the cooling airflow of the air system and the overall performance of the engine. The results show that, for the design condition, the CMC turbine blade can reduce the cooling airflow of the air system by approximately 10%, and the net thrust is increased by 6.07–7.98%. For the off-design conditions, with the CSCT, the specific fuel consumption can be reduced by 3.06–5.73% while ensuring that the engine net thrust remains unchanged. A comprehensive analysis of the performance for both the design point and off-design points indicates that the use of CMC for high-pressure turbine (HPT) guide vanes and rotor blades yields significant performance benefits, while the performance improvement from the use of CMC for low-pressure turbine (LPT) rotor blades is minimal.