Bottom Of Tower Research Articles

Time‐Series Load Online Prediction of Wind Turbine Based on Adaptive Multisource Operational Data Fusion

Aiming at the problem that the stochastic change of wind turbine generator (WTG) working conditions and the complex nonlinear relationship between load and operation data make it difficult to predict the short‐term load online, this paper proposes an adaptive multi‐information source data fusion online prediction method for WTG load. Random forest (RF) and WaveNet time series (WTS) are established as subinformation source models, and the influence of input features and historical data on load prediction is considered from horizontal and vertical dimensions. In order to reduce the influence of original data completeness on load prediction, the deviation degree of load prediction of RF and WTS is analyzed. The deviation degree of the subinformation source model is used as the basis for judgment, and it is fused into a multi‐information source load model with adaptive deviation degree analysis to predict the loads on the blades, tower top, and tower bottom of the wind turbine. According to the 15 MW semisubmersible offshore WTG load prediction example, the prediction error of this method is about 4% under normal data conditions and 6% under abnormal data conditions, and the calculation time of 200 sets of test data is 0.053 s, which meets the needs of pitch control and has the potential to be applied in the optimization of pitch control strategy.

Impact of pressure on coking of vacuum residue

AbstractThermal conversion of vacuum tower bottoms (VTB) and its narrow‐cut distillation fractions were studied at 530°C between 0.1 and 2 MPa pressure to assess the effect of the reaction pressure on coking. Coke yield in the VTB conversion increased with pressure, which was found to be mostly due to the enhanced coking of the 700°C+ narrow cut. The microcarbon residue in the liquid remained unaffected. The yield of products with a boiling point below 510°C, including distillate and by‐product lights, decreased with the pressure increase. The trend was a cumulative effect of the increased yields from the VTB cuts boiling below 635°C and the decreased yields from the heavier cuts. Admixing different VTB cuts into the VTB feed resulted in the weighted average changes with no synergistic or antagonistic effects.

Deformation Monitoring of Monopole Communication Towers Based on Multi-Source Data Fusion

Monopole communication towers play an irreplaceable role in modern communication systems. Because of its high flexibility, lateral loads control the deformation of a monopole communication tower. Dynamic displacement can be used to describe structural vibration characteristics and real-time deformation situations. Therefore, this article proposes a monopole communication tower deformation monitoring method based on multi-source data fusion using dynamic displacement as the evaluation indicator. This method calculates the strain displacement using the strain-mode superposition methodology. Then, the strain displacement and acceleration obtained are processed using Kalman filtering technology to reconstruct the real-time displacements of the monopole communication tower. The effectiveness of this method was verified using numerical simulations and model experiments, respectively. In addition, parametric analysis shows that this method is suitable for processing multi-rate data, has good noise resistance in strong noise environments, and can effectively reconstruct the displacement near the tower bottom. The results indicate that the method has favorable robustness and can accurately reconstruct low-frequency and high-frequency displacements of the monopole communication tower.

Feasibility of Carnauba Wax Rejuvenators for Asphalt Concrete with Vacuum Tower Bottom Binder

This study addresses the need for effective rejuvenators in asphalt concrete mixtures containing Vacuum Tower Bottom (VB) binder, a by-product of petroleum refining. We investigated the use of a softening rejuvenator, comprising Carnauba (5.5%), Soybean oil (3%), water (81%), surfactant (1.5%), and additive (3%) from a Korean refining company, to mitigate the brittleness of VB binder. Laboratory experiments were conducted to compare the performance of the modified binder with the original hardened binder. The results showed that adding the rejuvenator improved the properties of the VB binder. Optimal asphalt grades were achieved with a 2% content of the softening additive in the VB binder. The rejuvenator enhanced moisture resistance, leading to settlements comparable to the control asphalt. Settlements after 20,000 load repetitions were 11.49 mm for the modified mixture, which were slightly better than the control material at 12.44 mm. Moisture stripping points occurred at around 16,000 cycles for the modified mixture, while the control material experienced them at approximately 13,000 cycles. Under freeze-thaw cycles, the modified mixture exhibited enhanced durability compared to the control mixture. The control mixture experienced a significant increase in rutting value of approximately 59.7% (from 12.4 mm to 19.7 mm), while the modified mixture showed a relatively lower increase of approximately 37.4% (from 11.5 mm to 15.8 mm). Additionally, the modified VB mixture demonstrated approximately 7.8% higher dynamic modulus at lower temperatures, indicating improved mechanical properties. It also displayed superior fatigue crack resistance, with a fatigue life of 18,385 cycles compared to 15,775 cycles for the control asphalt. Field results confirmed that the VB asphalt mixture with the rejuvenator achieved comparable site compactness to the control mixture, indicating successful compaction performance. These findings highlight the rejuvenator’s efficacy in mitigating binder stiffening and restoring the original state of aged asphalt binders.

Improving the performance and rheological properties of RAP binders using gilsonite/nanoclay and softer binder

One of the ways to improve the performance of asphalt containing RAP is the use of a modified softer binder, which can enhance the rheological and performance characteristics. In this study, to improve the rutting and fatigue properties of reclaimed asphalt binder (RAB), a softer binder containing vacuum tower bottom (VTB) and Gilsonite/Nanoclay (Gil/Nc) composite were used. In this regard, the behavior of modified RAP binders has been controlled and analyzed using physical, rheological, and performance criteria from a laboratory test and ANOVA statistical method. The three scenarios designed in this research included a neat binder, RAB containing a soft binder, and RAB containing Gilsonite and different percentages of Nanoclay. The results showed that the modified softer binders (MSB) due to the presence of a high percentage of asphaltene in Gilsonite cause a quasi-solid behavior with a lower decay rate against plastic strains and improve rutting resistance at high PG temperature. The results of the BBR test showed that despite the negative effect of the Gil/Nc combination on the low-temperature behavior, the presence of VTB containing significant aromatic compounds compensated this problem to a large extent. The simultaneous results of DSR and BBR tests showed that RAB25_Gil/Nc6, RAB50_Gil/Nc6, and RAB50_Gil/Nc3 binders with useful temperature ranges of 97.5 °C, 97.1 °C, and 94.2 °C have the best performance. The outcomes of the LAS test showed that MSB increases fatigue life and reduces the probability of cracking of RAB. MSB containing Nc6 performs better due to the formation of an elastic network due to the strong interaction between nanoparticles and functional groups of the binder. The statistical analysis based on the laboratory results showed that the changes in dosage of the Nc and RAB have a significant impact on the performance characteristics. According to technical and functional considerations, MSB_Gil/Nc6 combination was proposed for modification of the binder containing RAB50.

Time-domain floater stress analysis for a floating wind turbine

There are increasing focuses on developing cost-effective floating wind turbines, for which efficient stress analysis methods are needed for floater structural design. Most of the today's studies focus on global analysis methods in which the floater is assumed as a rigid body or multiple rigid bodies and the stress distributions in the floater cannot be directly obtained. As part of the COWI Fonden funded EMULF project, a summary about the methodology, the numerical modeling procedure and the verification for stress response analysis of a semi-submersible floater for a 15MW wind turbine is presented. This analysis procedure includes the regeneration of the hydrodynamic pressure loads on the external wet surface of the floater due to wave diffraction, radiation and hydrostatic pressure change, and the application of these pressure loads, together with the time-varying gravity due motions, the inertial loads and the forces/moments at the boundaries (i.e. tower bottom and mooring line fairleads) of the floater to obtain the deformation and the stresses of the floater in the time domain. The analysis procedure is implemented in a developed MATLAB code and the DNV software package. The importance of the different hydrodynamic pressure components was discussed considering representative sea states. A verification of the obtained stress time series and statistics using this method against the regeneration from a linear frequency-domain approach was made considering irregular wave actions only, and a very good agreement was obtained. The developed methodology can provide an efficient solution for structural design analysis of floating wind turbines.

Experimental Study on Effect of Water Depth on Earthquake Response of a Deep-water Cable-stayed Bridge Tower

With the aim of investigating the effect of water depth on the earthquake response of a deep-water cable-stayed bridge tower, this study designed and manufactured a large-scale bridge tower model, taking a cable-stayed bridge across a deep reservoir of a hydropower station as a reference. Under the boundary conditions similar to the reference, shaking table tests were conducted to reflect the structural response of the bridge tower under white noise and earthquake actions at different water depths. The time history curve of the bridge tower’s structural response was recorded and used to investigate the variations in the natural frequency, displacement, stress and strain of a deep-water cable-stayed bridge tower at different water depths under earthquake actions. The results showed that the natural frequency of the bridge tower decreased almost linearly with the increase in the water depth. The displacement at the tower top increased gradually with the increase in the water depth under earthquake actions. In addition, the stress and strain at the tower bottom increased almost linearly in the transverse direction and nonlinearly in the longitudinal direction with the increase in the water depth.

Predictions for Bending Strain at the Tower Bottom of Offshore Wind Turbine Based on the LSTM Model

In recent years, the demand and requirement for renewable energy have significantly increased due to concerns regarding energy security and the climate crisis. This has led to a significant focus on wind power generation. As the deployment of wind turbines continues to rise, there is a growing need to assess their lifespan and improve their stability. Access to accurate load data is crucial for enhancing safety and conducting remaining life assessments of wind turbines. However, maintaining and ensuring the reliability of measurement systems for long-term load data accumulation, stability assessments, and residual life evaluations can be challenging. As a result, numerous studies have been conducted on load prediction for wind turbines. However, existing load prediction models based on 10 min statistical data cannot adequately capture the short-term load variations experienced by wind turbines. Therefore, it is essential to develop models capable of predicting load with a high temporal resolution to enhance reliability, especially with the increasing scale and development of floating wind turbines. In this paper, we developed prediction models with a 50 Hz resolution for the bending strain at the tower bottom of offshore wind turbines by combining SCADA data and acceleration data using machine learning techniques and analyzed the results. The load prediction models demonstrated high accuracy, with a mean absolute percentage error below 4%.

Finite Element Simulation and Experiment of Temporary Active Transverse Brace of Inward-inclined Bridge Tower Construction

For the bridge tower with large inclination angle, the beam element in Midas finite element software is used to model and analyze the bridge tower structure, and its accuracy is difficult to guarantee. In this paper, taking the construction of a suspension bridge’s inward-inclined tower as the research background, the finite element simulation of the inward-inclined bridge tower is carried out by using the two modeling methods of the beam element and the solid element. The calculation accuracy of the beam element model, the specific position and the jacking force applied by the active transverse brace of the inward-inclined bridge tower are determined, and the field test of the tower bottom stress during the construction process is performed. The results show that: when the inclination angle of the bridge tower is small (5 °), the beam element element is used for modeling and analysis, which has fast calculation speed and high calculation accuracy; When the inclination angle is 15 °, the error of the beam element model exceeds 30%, and it is recommended to use the solid model for calculation; the active cross brace plays a key role in controlling the stress at the bottom of the tower column before the lower cross beam is applied. And after the construction of the cross beam, the active cross brace forms a closed frame structure with the lower tower column, and the subsequent cross brace has little impact on the stress at the bottom of the tower column; Compared with increasing the number of temporary cross braces, increasing the jacking force can improve the stress at the bottom of the tower. And by adjusting the position of the active cross brace and applying the appropriate active jacking force, the stress at the root of the tower column can be greatly improved.

Effects of Blade Extension on Power Production and Ultimate Loads of Wind Turbines

Blade extension is an important type of technical transformation to improve the energy production of turbines for early-built wind farms. To evaluate the effects of blade extension on wind turbines, a 1.5 MW commercial wind turbine with three 37.5 m long blades is taken as the research object; the power enhancement and the load variations are systemically evaluated for three different blade extension lengths (1 m, 1.5 m and 2 m) resorting to the software GH-Bladed. The load cases cover all the requirements of the IEC-61400-1 standard. It is found that the optimum tip-speed ratio λopt and the corresponding power coefficient CPmax increase with the blade extension length. The annual energy power production is enhanced by about 3%, 4% and 6% for the extension length of 1 m, 1.5 m and 2 m, respectively. The steady loads and dynamic loads, especially the thrust force of the rotor, the flapwise moment of the blade root and the overturning moment at the tower bottom, are significantly enhanced as the improvement of the power. In particular, the percentage increase of these quantities are over 10% when the extension achieves 2 m. It is also shown that blade extension can produce good economic benefit and the benefit improves with the extension length within the safety margin. The paper provides an important reference for this type of technical transformation.

Analytical solutions for thermal effects of suspension bridges based on a surrogate model with longitudinal restraint stiffness

Ambient temperature variation has a significant influence on the deformation of main cables and the internal force of towers of long-span suspension bridges. Currently, the finite element method (FEM) is mainly used for these calculations. This paper intends to present an analytical solution of the thermal effects on suspension bridges. First, three typical temperature patterns are defined. Then, a surrogate model is established by replacing the longitudinal restraint stiffness of the main cable and the tower lateral stiffness with a set of equivalent horizontal springs. The stiffnesses of the suspended cables are formulated according to the energy conservation principle, while the tower lateral stiffnesses are obtained by incorporating the pure bending and Euler buckling solutions, namely considering the effect of the axial force placed on the tower top. Following the force equilibrium conditions, two governing equations are built, which can calculate the variations in the longitudinal displacement of the tower top caused by the temperature variation. After that, some other significant thermal effects, such as the horizontal force of the main cable, the sag of the main cable and the bending moment of the tower bottom, are obtained. Finally, the analytical solution is verified through the field test data of the Tsing Ma Bridge in Hong Kong and the FEM results of four typical examples. The proposed surrogate model offers a quick and easy approach for thermal effect analysis with acceptable accuracy. It is helpful to clarify the mechanical nature of temperature effects to facilitate the preliminary bridge design.

Safety assessment of ancient buddhist pagoda induced by underpass metro tunnel blasting vibration

In the blasting excavation project of the subway tunnel in the urban area, ensuring the safety of the surface buildings (structures) above the crossing area is the key concern. This paper is based on the blasting project of the ancient pagoda (Shengxiang Pagoda) under the tunnel between Pengliuyang Road Station and Simenkou Station of Wuhan Metro Line 5. To protect the integrity of the ancient buildings, this paper mainly adopts the numerical simulation method to analyze the dynamic response characteristics of the tower above the subway and realizes the safety assessment of the tower based on the maximum principal stress and vibration velocity control. The results show that the maximum error rate between the measured data and the numerical simulation results is only 11.9 %, which verifies the reliability of the numerical model and parameters. In the process of blasting vibration propagation, the vibration velocity of the tower body is affected by the whiplash effect and the elevation amplification effect. The vibration velocity of the tower bottom is 0.29 cm / s, and the vibration velocity of the tower tip reaches 4.29 cm / s. The vibration velocity of the upper part of the tower is much larger than that of the lower part. The stress distribution of the tower body is accompanied by stress concentration, with the maximum reaching 0.0442 MPa and the minimum only 0.014 MPa. The safety assessment of the ancient pagoda from the aspects of structural strength and vibration velocity can determine that the structure is safe under this condition. The research results are of great significance to the analysis of dynamic response characteristics and safety evaluation of ancient buildings under blasting load in urban complex environments.

Comparative Analysis & Design of RCC & Steel Preheater Tower Structure by Using STAAD. Pro

A liquid material after water concrete is the most consuming material in the world, concrete is the most important construction material used extensively to construct buildings, dams, roads, etc. As we know that concrete is a composite material with cement, coarse & fine aggregates bonding together with water that gives hardness with time. As per the 2018 year statistics, India is the second largest producer of cement in the world with 460 million tonnes per year which is over 8% of the global installed capacity. Cement is the most important material in concrete, In India, at present, there are 120 major cement plants and nearly 300 mini cement plants are manufacturing the cement. In Cement plants ‘Preheater tower’ is used, these preheater tower consists of several cyclones, these raw materials are fed at the top of the preheater tower through cyclones it travels to the bottom of the preheater tower, each cyclone in the preheater serves as a heat exchanger and a separate. In this project, a comparative analysis & design will be done between both the RCC structure & Steel structure Preheater tower as per Indian design standards by using Staad Pro software. In this design process, the loads which are affecting the structure will be taken and designed. And also the pros & cons will be discussed between the RCC & Steel structure Preheater tower. Here the height of the RCC and steel Preheater tower taking as 110 meters. It is observed that Maximum displacements at a height of 110 mts in RCC preheater tower are 130.59 mm and Steel preheater tower is 102.238 mm. The Maximum Moment at critical load combination is more in RCC preheater tower (i.e 205.6 kN.m) than Steel preheater tower (i.e 190.1 kN.m).The Maximum shear at critical load combination is more in Steel preheater tower 62.0 kN is more than RCC preheater tower 28.7 kN.

Dynamic response of a SWATH vessel for installing pre-assembled floating wind turbines

New and efficient installation concepts which can reduce the cost of developing an offshore wind farm are of particular interest. This paper explores a promising concept using the small water-plane area twin-hull vessel (SWATH) to install pre-assembled wind turbines (OWT) onto floating spar foundations. A focus is placed on the hydrodynamic performance of the SWATH and the response analysis of the coupled SWATH-spar system. Firstly, the numerically calculated difference-frequency wave force effect and damping forces of the original SWATH were verified with experimental data. Secondly, the original SWATH was modified to satisfy the criteria of weight-carrying capacity and hydrostatic stability. Thirdly, a multibody numerical model for the SWATH-spar system was developed, in which the hydrodynamic and mechanical couplings between the SWATH and a spar were considered. The SWATH is equipped with a dynamic positioning system to counteract the slow-drift wave force effects. The nonlinear time-domain simulations were carried out for the mating stage when a wind turbine is lifted above the spar foundation. Based on the analysis of statistics of the relative displacement and velocity of the tower bottom and the spar top, the installation concept with SWATH is found to be of decent performance. Finally, recommendations are provided for future research on this concept, which contributes to developing next-generation installation concepts for bottom-fixed and floating wind farms.

Dynamic response analyses of long-span cable-stayed bridges subjected to pulse-type ground motions

This paper presents the dynamic response analyses of a special long-span cable-stayed bridge with the main span length of 680 (m) subjected to pulse-type ground motions. The 1/100 scaled shaking table test are developed herein to verify the accuracy and correctness of the 3D finite element (FE) model of the examined long-span cable-stayed bridge on the software platform of SAP2000. To systematically investigate the influence on the seismic responses and on the selection of the nonlinear viscous damper parameters of the employed long-span cable-stayed bridge both the near-fault pulse-type ground motions and the far-field ground motions are selected as the seismic inputs of FE model. Some important conclusions are drawn that the near-fault ground motions usually causes the larger peak responses (e.g., Tower top displacement, girder end displacement, and moment of tower bottom) of the long-span cable-stayed bridge compared with the far-field motions, namely the near-fault ground motions are more destructive to the structures. The displacement responses can be amplified approximately 2–3 times and the damper parameters (Damping coefficient C and damping index α) of nonlinear viscous dampers can be affected by the ground motion characteristics. The damper parameter values are changed from the C = 3000 and α = 0.3 in far-field earthquakes to the C = 6000 and α = 0.2 in near-fault earthquakes, namely the near-fault ground motions obviously increase the demand of energy consumption of general nonlinear viscous dampers.

Intercriteria Analysis to Diagnose the Reasons for Increased Fouling in a Commercial Ebullated Bed Vacuum Residue Hydrocracker.

The intercriteria analysis developed on the base of intuitionistic fuzziness and index matrices was applied to evaluate processing data of the LUKOIL Neftohim Burgas H-Oil ebullated bed vacuum residue hydrocracker with the aim of revealing the reasons for increased fouling registered during the 3rd cycle of the H-Oil hydrocracker. It was found that when the ratio of the ΔT of the 1st reactor to the ΔT of the 2nd reactor gets lower than 2.0, an excessive H-Oil equipment fouling occurs. The fouling was also found to be favored by processing of lower Conradson carbon content vacuum residual oils and increased throughput and depressed by increasing the dosage of the HCAT nanodispersed catalyst. The fouling in the atmospheric tower bottom section is facilitated by a lower aromatic content in the atmospheric tower bottom product. The addition of FCC slurry oil not only increases aromatic content but also dissolves some of the asphaltenes in the atmospheric residual hydrocracked oil and decreases its colloidal instability index. The fouling in the vacuum tower bottom section is facilitated by a higher saturate content in the VTB. Surprisingly, it was found that the asphaltene content in the VTB depresses the fouling rate. No relation was found of the sediment content in the hydrocracked residual oils measured by hot filtration tests and by the centrifuge method to the equipment fouling of the H-Oil hydrocracker.

Analysis of the causes of the cracking of tube bundles of 316L stainless steel Shell-and-Tube heat exchanger

In an oil field, numerous tube bundles in the reboiler at the bottom of a regeneration tower cracked and leaked after only 2.8 years of service. Analysis was conducted on the material properties, failure characteristics, and corrosion products of the cracked 316L stainless steel tube bundles, and the causes of the cracking of the tube bundles of the heat exchanger were clarified. The results indicated that the failure of the tube bundles was caused by typical stress corrosion cracking (SCC), and the cracking originated from the pitting corrosion that occurred on the exterior surface of the tube bundles. The chemical composition, metallography, and mechanical properties of the failed tube bundles met standard requirements. The synergistic effect of chloride ions and oxygen in the solution was the main cause of the SCC of the heat exchanger tube bundles.

Numerical simulation study on gas-solid flow characteristics and SO2 removal characteristics in circulating fluidized bed desulfurization tower

Circulating fluidized bed flue gas desulfurization technology is widely used in the world. The computational particle fluid dynamics (CPFD) numerical simulation method was used to study the gas-solid two-phase flow and desulfurization characteristics in the circulating fluidized bed desulfurization tower. The CPFD method is based on the MP-PIC method, which uses the stochastic particle method for the particle phase and the Euler method for the fluid phase to solve the dense particle flow. The established model was firstly verified by the experimental results of gas-solid flow field and desulfurization efficiency. Then, the effects of flue gas parameters on the flow field in the desulfurization tower and the effects of flue gas parameters, SO2 inlet concentration, and Ca/S on desulfurization efficiency were numerically simulated. An effective optimization scheme was also proposed to improve the desulfurization efficiency. The research results showed that the CPFD simulation results were in good agreement with the experimental results, which proved the reliability of the method. The particle motion state in the bed of the desulfurization tower presents a core-annular flow. As the flue gas inlet flow increased, the distribution of flue gas and particles has a serious deviation, and the desulfurization efficiency also decreased. The desulfurization efficiency will decrease with the increased of SO2 inlet concentration and increased with the increased of Ca/S. According to the distribution of SO2 concentration in the bed, three characteristic desulfurization zones can be proposed, namely, the initial mixing process zone, the high-efficiency desulfurization process zone, and the low-efficiency desulfurization process zone. Installing a baffle at the bottom of the desulfurization tower can optimize the distribution of gas-solid two-phase flow in the bed and the desulfurization efficiency.

DESIGN GUIDELINES FOR CHEMICAL TREATMENTS IN DISTILLATION COLUMNS

Distillation is the application and removal of heat to separate hydrocarbons by their relative volatility or boiling points. This necessary addition of heat normally in the feed stream or at the tower bottoms via a reboiler can also lead to unwanted consequences such as polymerization, corrosion and reverse solubility. The removal of heat can lead to sedimentation, solubility effects, corrosion and precipitation. The concentration of certain constituents by the distillation process can cause corrosion, polymerization, sediment fouling and flow phenomena effects. Keywords: solubility, corrosion, polymerization, distillation, heat, hydrocarbons, sediment, precipitation, fouling

Optimization of a vertical axis wind turbine with a deflector under unsteady wind conditions via Taguchi and neural network applications

Vertical axis wind turbines (VAWTs), so named because of their vertical axis of rotation, are a sustainable, opportune, and versatile means of producing energy. Their operation is not dependent on wind direction, making them suitable for use in settings with turbulent and inconsistent winds (e.g., urban locations), and they can be installed at the bottom of towers for easier installation and maintenance. However, unsteady wind may cause a vertical axis wind turbine (VAWT) to operate under drag-controlled conditions and reduce its performance. The power coefficient of a VAWT under unsteady wind conditions is heavily impacted by the tip speed ratio (TSR). Understanding and optimizing TSR is critical to making VAWTs a more viable and attractive option for sustainable energy production. Deflectors have been shown to improve the aerodynamic performance of wind turbines. In the present study, the Taguchi method is used in the experimental design, and a high-fitting neural network (NN) model based on computational fluid dynamics (CFD) data is adopted to predict the optimal mean TSR for a VAWT operation with a deflector. The amplitude and frequency fluctuations of the mean inlet velocity are used to specify the unsteady wind conditions. The results show that the imposed unsteady wind reduces the average power coefficient (Cp-) of the VAWT. By applying the Taguchi method and NN analysis to the impact of unsteady wind conditions, it is found that the mean TSR (TSRmean) is the factor producing the greatest impact on Cp-. The optimal TSRmean is evaluated by the NN model. In light of the recommendation from the NN predictions, the Cp- value from CFD can be improved by up to 3.58 folds under the optimal TSRmean. Furthermore, the relative errors of predicted Cp- values between the NN and CFD simulation are less than 4%, showing the reliability of predictions of the developed NN model in efficiently calculating the optimal operation for a VAWT.