Blade Shape Research Articles

Simulation of unsteady process of converting liquid to solid phase inside a solar storage system utilizing nanoparticles

The completion time of discharging has been reduced in current study with installing fins and dispersing additives. The tank has an insulated sinusoidal bottom wall and is filled with water. The conduction mode of water has been improved with dispersing nanoparticles. To calculate the conductivity, the fraction and configurations of powders were considered as variables. The equations for modeling were simplified by considering the assumption of neglecting convection mode. Galerkin modeling incorporating implicit methods has been selected to achieve the modeling. With increasing ϕ form 0.02 to twice amount, the time of freezing declines around 16.9 %. If the tank is filled with water, it takes 300.06 s to reach full solidification. The rate of process enhances about 32.61 % with loading nanoparticles with blade shape of blade.

Numerical Investigation on the influence of meteorological conditions on wind turbine icing

Keeping the blade structure and shape in the design condition is the premise and guarantee for efficient operation of wing turbine, but wet and cold climate will lead to icing blade, then the blade shapes were changed and the output power of the wind turbine is reduced. A numerical frame for wind turbine icing was developed in present work, which consists of a numerical method for impingement of water droplets based on the multiple frames of reference and Euler method and a 3D heat and mass transferring method for wind turbine icing, then the effects of several meteorological parameters, including the temperature, Liquid Water Content (LWC), Mean Volume Diameter (MVD) and the inflow velocity, on ice shape of the blade were investigated in the numerical frame. The present method can provide supports for prediction of icing process and aerodynamic characteristic after icing of wind turbine blades.

Design of the parametric appearance of the power plant for modifications of the regional passenger aircraft An-158

The object of research is the process of remotorization of a regional passenger aircraft to increase its fuel efficiency. Based on the conceptual requirements for the remotorization of the An-158 aircraft with turbojet bypass engines, a parametric appearance of three modifications of this aircraft with turboprop engines for 80, 100, and 120 passenger seats was formed. The study was carried out on the basis of the well-known modular software systems «Integration 2.1» and «Air propeller 2.2» for typical flight profiles of the An-158 aircraft. Improved procedures of weight design and determination of the takeoff characteristics of aircraft with different types of power plant engines have made it possible to identify the most advantageous flight speeds of aircraft modifications with a turboprop engine corresponding to different flight masses. The results of the study of flight performance for optimal and «non-optimal» modifications of the aircraft are reported. The parametric appearance of the propeller was formed, the shape of the propeller blade for the cruising flight mode was determined for modifying the aircraft with a maximum number of passengers – 120 people. It is shown that the propeller for this modification of the aircraft cannot have less than 8 blades since with a smaller number of blades, the maximum chord of the propeller blade increases. The inductive power costs increase significantly due to the small elongation of the blades and, as a result, the flight efficiency of the propeller decreases. It is shown that the total fuel consumption for the entire typical flight of all modifications of the aircraft with turboprop engine at all studied flight speeds is less than the total fuel consumption of the An-158 base aircraft

The study of vertical-axis wind turbine based on immersed boundary method

In this article, a modified immersed boundary method (IBM) with a ghost-cells strategy is introduced to study a kind of vertical-axis wind turbine (VAWT). In order to improve the accuracy of the numerical calculation and enhance its adaptability, some treatments on the IBM for the VAWT especially are carried out. The method is testified by the numerical simulation of an Eppler387 airfoil. With the help of the method, some flowing characteristics of the wind turbine have been thoroughly observed and understood. Furthermore, the effects of blade shape, tip vortex and secondary flowing on the turbine performance are discussed in detail based on the numerical results.

Effect of impeller and diffuser matching optimization on broadening operating range of storage pump

A large volute-type centrifugal pump (LVTCP) is a crucial component of a pumped-storage power station. A steady increase in the single-operation power of each large pump station gradually causes unstable operation and substantial energy loss in engineering applications. The Taguchi design and numerical calculations are combined in this study to enhance the efficiency and operational stability of an LVTCP and reduce energy consumption. The impeller blade shape is designed using an inverse design method, whereas the diffuser shape is designed using a positive design method. Optimization is performed to achieve the desired efficiency under 0.9Qd, 1.0Qd, and 1.1Qd using 12 design variables. The significant effect of each design variable on the objective is identified, and the increase in efficiency in the high-efficiency zone after optimization is investigated. The results show that the efficiency of the three optimized schemes improved significantly, with maximum increases of 3.47 %, 2.96 %, and 3.2 % under 0.9Qd, 1.0Qd, and 1.1Qd, respectively. Additionally, the optimized internal flow characteristics of the pump improved significantly, the vortex in the diffuser runner is eliminated, and the energy losses at the diffuser and volute tongue decreased significantly, thus effectively alleviating energy loss in the pump. Based on the efficient house theory, a set of design schemes with the largest range of high-efficiency zones is calculated; these schemes improve the overall operating efficiency and stability of the storage pump under design and non-design conditions. This study shows that multicomponent matching optimization based on the Taguchi is vital to the high efficiency, energy saving, and stability of LVTCP under multi-operating conditions.

Low-Cost Maximum Power Point Tracking Strategy and Protection Circuit Applied to an Ayanz Wind Turbine with Screw Blades

This paper provides three different research contributions applied to a Wind Turbine patented in 1606 by the inventor Jerónimo de Ayanz y Beaumont. The windmill under study is the Ayanz Wind Turbine with screw blades. The first contribution consists of an experimental characterization of the Ayanz Wind Turbine, incorporating the enclosure proposed at the patent and showing that the efficiency of the wind turbine is increased between 70% and 90% due to the enclosure being employed. As not many details about the shape of the screw blades are provided at the patent, in this article the nowadays well-studied and commercially available Archimedes Spiral Wind Turbine blade is utilized. It has been observed that by using an enclosure with a cylindrical shape, not only the efficiency of the wind turbine is increased, but the visual impact is reduced as seeing the blades rotating is avoided, which is a very important fact for many potential individual users of this wind turbine. In addition, it also enables the use of a protective mesh for birds, almost totally reducing the probability of bird deaths. The second contribution consists in a simple and low-cost Maximum Power Point Tracking (MPPT) strategy for the wind turbine, which only uses an AC three-phase impedance to capture the maximum energy from the wind, enabling to eliminate the DC-DC converter and microprocessor employed typically for this purpose. Due to this, the cost, complexity, failure rate, and power losses of the electronic power circuit are reduced which is very welcomed for small-scale wind turbines. Finally, the last contribution is a protection electronic circuit that fulfills several objectives: to brake the wind turbine under high winds and to disconnect and protect it when over-currents occur and when the voltage range of the batteries connected to the wind turbine is outside their safety range.

Genetic diversity of kale (Brassica oleracea L. var acephala) using agro-morphological and simple sequence repeat (SSR) markers

Kale (Brassica oleracea. var. acephala) is a nutrient-rich green leafy vegetable consumed as food and used in traditional medicine worldwide. An essential step in describing the available genetic resources and ensuring their effective use in breeding programs is to characterize the genetic diversity of available germplasm. In this study, the genetic diversity and structure of 26 kale accessions from South-East Europe were examined using 26 agro-morphological traits collected in the field and 12 simple sequence repeat (SSR) markers. Considerable agro-morphological variability was found in most quantitative (CV = 17.26–42.42%) and qualitative (H' = 0.61–1.79) traits. Multifactorial analysis (MFA) showed that country of origin (33.01%) and morphotype (32.30%) significantly influenced kale diversification. Leaf blade shape (20.62%), leaf incision (19.43%), anthocyanin distribution (16.43%), and leaf colour (15.55%) were the traits that most clearly differentiated accessions. The three common commercial kale cultivars were identified as independent outliers that differed from the other kale accessions in both MFA and UPGMA clustering analysis. The SSR markers were highly informative with 108 alleles and polymorphic information content ranging from 0.395 to 0.856. Strong genetic diversity was detected at the accession level (H' = 0.58) while genetic differentiation was low (Fst = 0.05). Similar to UPGMA clustering, Bayesian clustering suggests that the kale collection can be divided into four clusters with a high degree of admixture and no geographic grouping pattern is apparent. Overall, the study showed that the kale collection studied represents a valuable reservoir of genetic and agro-morphological variability that could be used for future breeding initiatives.

Comparative Study of the Blade Number and Airfoil Profile Impacts on the Twist/Chord Distribution of a Small Wind Turbine Blade

The blade number and airfoil profile effects on the blade shape of a small horizontal-axis wind turbine (SHWT) were investigated. For this purpose, the NACA4412, SG6042, and SG6043 airfoils, as well as 2, 3, and 4 blades, were considered. Then, two optimization processes were used: first, the blades were designed to maximize the power coefficient ( C p ), and then a multiobjective optimization that included both maximizing C p and maximizing the starting torque ( Q s ) was employed. The differential evolution (DE) algorithm was employed to perform the optimization, and the blade element momentum aerodynamic approach was used to conduct the relevant computations. Also, to ensure the performance of the optimal blades, the computational fluid dynamics method was employed as well. The findings revealed that regardless of the number of blades and the type of airfoil, raising the twist angle ( θ p ) and chord length ( c ) along the radial direction of the blade, especially at the root part, helps increase the Q s . It was observed that increasing the number of blades does not have a significant effect on the θ p distribution of the selected airfoils, but the c of the blades fitted with all three airfoils decreases. Regardless of the number of blades, while the geometry of blades utilizing the NACA4412 and SG6042 airfoils are close to each other, the blade with the SG6043 airfoil has the shortest c , which reduces the generated Q s of blades fitted with this airfoil. The results also establish that by increasing the number of blades from 2 to 3, the power coefficient ( C p ) of the blades fitted with all three airfoils increases, but by further increasing the number of blades from 3 to 4, the change in C p completely depends on the airfoil profile.

Clovis point allometry, modularity, and integration: Exploring shape variation due to tool use with landmark-based geometric morphometrics.

Landmark-based geometric morphometrics (LGM) is most often used in archaeology to characterize and differentiate groups of artifacts, but it can be used for much more. We demonstrate LGM's power to uncover new insights by exploring stone-tool allometry, modularity, and integration using a sample of 100 western North American Clovis points. Here, allometry concerns how stone tools change in shape as their size changes through their use-lives, and modularity and integration concern how the constituent parts of a tool work together. We show that Clovis points are surprisingly complex tools. When their blades and hafts are defined technologically, rather than arbitrarily, they unambiguously exhibit allometry, and their hafts and blades are modular and highly integrated. We use these analyses to further explore questions about Clovis points, including the differences between cache and non-cache points. Finally, we use heuristic haft-size categories to examine functional constraints on the shape and size of hafts and blades. This work illustrates the importance of using accurate measurements of point components rather than estimates or proxies, which can lead to unfounded inferences. These analytical approaches and accompanying R code are easily transferable to other research questions of stone-tool use.

Unveiling particle deposition characteristics on flat plate with a shaped film cooling hole

Particle deposition on turbine blades poses a significant challenge to the safe operation of gas turbines. The blockage of film-cooling holes and alteration in the aerodynamic shape of blades affect the turbine's efficiency, highlighting the importance of reducing particle deposition on turbine blades. To investigate the characteristics and potential mechanisms of deposition, experimental and numerical studies were conducted on two typical film-cooling holes: cylindrical and 777-shaped. A multi-perspective scanning method was used to measure the three-dimensional deposition topography on flat plates under a particle-laden environment. The wax deposition experiments showed that the deposition thickness of both holes increased with the blowing ratio. However, the 777-shaped hole exhibited a 10–40% reduction in deposition compared with the cylindrical hole. The computational predictions of deposition patterns agreed well with the experimental results. The numerical simulations revealed that the presence of film cooling reduced deposition in some areas but increased deposition in the vicinity of the film coverage region owing to the entrainment of vortices. Overall, this study further elucidates particle deposition characteristics and the influencing factors, which can guide the design of blade cooling systems with reduced deposition.

Blade optimization design of Savonius hydraulic turbine based on radial basis function surrogate model and L-SHADE algorithm

The blade is the component responsible for capturing energy in the Savonius hydraulic turbine, and a good blade shape can extract more energy from the flow field. The shape of the turbine blade is optimized in this paper. First, the blade shape is expressed parametrically using a third-order quasi-uniform B-spline curve controlled by two parametric variables. Then, some initial design schemes are obtained through the grid sampling method from the design space and the torque coefficients of all initial design schemes are calculated using computerized fluid dynamics (CFD). Following this, a radial basis function (RBF) surrogate model is established by using initial design schemes and their corresponding torque coefficients. Then, the RBF surrogate model is solved by applying the L-SHADE. Finally, the resulting best design scheme is validated and further analyzed using CFD. By comparing the performance of the turbine before and after optimization, it is found that the power coefficient of the turbine with the optimized blades is increased by 7.07% at the tip speed ratio of 1, and the power coefficients at other tip speed ratios are also increased. In addition, the optimized blade has higher peak torque coefficients and its length is shortened by 15.34%.

Experimental Study and 3D Optimization of Small-Scale Solar-Powered Radial Turbine Using 3D Printing Technology

Small-Scale Turbines (SSTs) are among the most important energy-extraction-enabling technologies in domestic power production systems. However, owing to centrifugal forces, the high rotating speed of SSTs causes excessive strains in the aerofoil portions of the turbine blades. In this paper, a structural performance analysis is provided by combining Finite Element Methods (FEM) with Computational Fluid Dynamics (CFD). The primary objective was to examine the mechanical stresses of a Small-Scale Radial Turbine (SSRT) constructed utilizing 3D printing technology and a novel plastic material, RGD 525, to construct a SSRT model experimentally. After introducing a suitable turbine aerodynamics model, the turbine assembly and related loads were translated to a structural model. Subsequently, a structural analysis was conducted under various loading situations to determine the influence of different rotational speed values and blade shapes on the stress distribution and displacement. Maximum von Mises and maximum main stresses are significantly affected by both the rotor rotational speed and the working fluid input temperature, according to the findings of this research. The maximum permitted deformation, on the other hand, was more influenced by rotational speed, while the maximum allowable fatigue life was more influenced by rotating speed and fluid intake temperature. Also, the region of the tip shroud in the rotor had greater deflection values of 21% of the blade tip width.

Oreocharis chenzhouensis, a new species of Gesneriaceae from southern Hunan, China

Oreocharis chenzhouensis, a new species, is described and illustrated from southern Hunan, China. The new species resembles O. burtii and O. sinohenryi in leaf blade shape and indumentum of the plants, but readily differs from the latter two in its leaf blade with a cuneate and usually asymmetric base, abaxially glabrous corolla tube, narrowly triangular calyx lobes, and one or no staminode. Following the IUCN Red List Criteria, O. chenzhouensis is assessed as “Vulnerable”.

Analysis of Influence of Pre-bend Blade Shape on Aeroelastic Characteristics of Wind Turbine Under Startup Condition

In this paper, a 2 MW wind turbine in the laboratory is taken as the research object, and the blades with pre-bending capacities of 2, 3, 4, and 5 m are designed, respectively, to study the influence of different pre-bending capacities on the aerodynamic elasticity of wind turbine under unstable operating conditions. Based on the professional simulation software of wind turbine multi-body dynamics, the parametric model with aero-elastic-control coupling is established, and the simulation calculation of different pre-bending blades is carried out. The results show that the aerodynamic deformation of the blade and the load at the blade root increase obviously with the increase of blade pre-bending. Under the starting condition of a wind turbine, larger blade pre-bending will lead to a significant increase in aerodynamic deformation of wind turbine blades under unstable operating conditions. It shows that the larger blade pre-bending amount will greatly increase the risk of aeroelastic instability of wind turbines under unstable operating conditions.

A novel method of optimizing the Savonius hydrokinetic turbine blades using Bezier curve

Renewable electricity is increasingly gaining importance due to the quest for energy security and the harmful effects of fuel-based energy sources. Savonius hydrokinetic turbine (SHKT) can be a suitable means to provide electricity using rivers, canals, etc. Optimization of blade shape can play a vital role in enhancing the efficiency of SHKTs. A novel method to generate blade shapes has been proposed in this work using a Bezier curve with six control points. The method involves splitting a blade into two halves and optimizing those separately to simultaneously increase the pressure difference and the normal incoming velocity. The generated blade shapes were studied using a 3D transient computational model, which was validated with the obtained experimental results. Results showed that the blades generated using the proposed model show superior performance compared to conventional semicircular blades as well as the blades generated using four points Taguchi method. The most optimum blade profile achieved a maximum power coefficient of 0.21 at a tip speed ratio of 0.8. The efficiency of this new blade profile was found to be 16.7% higher compared to the semicircular blade, while the best blade using four points method was merely 2.1% more efficient than the semicircular blade.

Dissipated energy and efficiency as objective functions for the design of the NeoVAD rotary blood pump.

Minimising haemolytic blood damage is an important objective when designing rotary blood pumps, however, calculating haemolysis can be computationally expensive and inaccurate. Efficiency and dissipated energy are much more easily calculable hydraulic parameters in the design and analysis of rotary blood pumps and although there is work to suggest that efficiency is not a good indicator of haemocompatibility, i.e. more efficient pumps do not necessarily cause less damage, there is recent speculation that dissipated energy can act as an easily calculable haemolysis analogue.This study shows that for design purposes, optimising for maximum efficiency and minimum dissipated energy are functionally the same as they are inherently and closely linked. Moreover a demonstration of rotary blood pump design has been completed using the NeoVAD paediatric left ventricular assist device optimising for both objective functions. The resulting designs appear similar in rotor blade shape and are similar in hydraulic performance.Clinical relevance- This reinforces the direct link between efficiency and dissipated energy when analysing rotary blood pumps at a given design operating point. This raises questions either of the claim that efficiency cannot be used as an easily calculable analogue for haemolysis or the validity of dissipated energy to act in this same manner.

Metapetrocosmea alba (Gesneriaceae), a new species from central Vietnam

Based on morphological comparison and literature consultation, a new species, Metapetrocosmea alba (Gesneriaceae), is confirmed from Bach Ma National Park, central Vietnam. This new species is similar to M. poilanei, but differs by its longer and white funnelform corolla and three staminodes. And it is easy to distinguish the new species from M. cycnostyla by its distinct stem, and the shape and size of leaf blade. A detailed morphological description and photographic illustration of the new species are provided along with ecological information and geographic distribution.

Aerodynamic Performance of Vertical-Axis Wind Turbines

The nonstationary separated incompressible flows around Darrieus and Savonius rotors of vertical-axis wind turbines were investigated through computational simulation using the Reynolds averaged Navier–Stokes equations and Spalart–Allmaras turbulence model. The implicit finite-volume algorithm, the basis of which was artificial compressibility method, was chosen to obtain the numerical solution. The series of computational and physical experiments for Darrieus rotors with varied numbers and shapes of blades were performed. The detailed visualization of the flow was presented. The turbulent flows surrounding the Darrieus and Savonius rotors were studied, and as a part of these investigations, the major phases of vortex progress were identified. For this purpose, three series of computer tests on the aerodynamic and power properties of Savonius rotors with two and three buckets were performed, and their results are also presented. The influence of tip-speed ratio, solidity, and Reynolds numbers on the power coefficients of the Darrieus and Savonius rotors was investigated. It has been demonstrated that increasing Reynolds number from 104 to 106 causes a rise in Darrieus rotors power coefficient from 0.15 up to 0.5. The maximum values of power coefficient are moved away from higher values of tip-speed ratio from 2 to 5 as a result of a decrease in Darrieus rotor solidity from 1.0 to 0.33. The greatest power coefficient for a Savonius rotor with two blades is 0.23 and for a Savonius rotor with three blades is 0.19.

Insight into the thermocapillary radiative flow of hybrid nanoliquid film over an infinite rotating disk with entropy generation and heat source

Research into hybrid nanofluid flow over a disk surface is growing due to numerous processes in marine or gas turbines, rotating disk reactors for biofuels generation, cooling of spinning equipment components and other industrial applications. The purpose of this research study is to examine the entropy generation for the transient thermocapillary flow of hybrid nanoliquid thin films across a disk surface with different shapes of nanoparticles. To analyze the nanomaterial, the Tiwari–Das hybrid nanofluid flow model is established, and in doing so, Prandtl’s boundary layer theory is incorporated into this model. The energy equation considers the impacts of thermal radiation, two different kinds of heat sources — namely an exponentially space-dependent heat source and a linear thermal heat source — and viscous dissipation. The nonlinear partial differential equations, which explain the flow processes, are transformed into the nondimensional ordinary differential equations (ODEs). Once the ODEs have been constructed, they are next solved using the bvp4c technique. In addition, the surface drag force and the rate of heat transfer are both evaluated as functions of the shape factor of the nanoparticles that are disseminated in the base fluid. The influence of significant parameters on the flow fields is depicted graphically, and adequate physical explanations are provided for each representation. One of the important findings of this study indicates that the largest amount of heat transfer can be accomplished at the disk surface by employing nanoparticles with blade shape, while this physical quantity is the least when nanoparticles with spherical shapes are used. The temperature profile grows as the thermal and exponential heat sources increase. Entropy generation improves with the increase in either the magnetic parameter or the Brinkman number.

Research on blade statistics measurement registration planning technology

Blade has the characteristics of high machining quality of complex curved surface. If there is no benchmark before machining, it is impossible to judge whether the blades before machining are qualified. Therefore, it is necessary to analyze the blade measurement data. Due to the large measurement point error and disordered distribution, it is necessary to optimize the blade registration. Therefore, blade model registration and positioning is particularly important in blade shape detection and analysis. First, preregistration is carried out based on the six point optimization selection of the blade. After preregistration, the selection method of registration control point set based on theoretical model and statistical error is proposed, planning the registration datum point set on the blade model. The registration control point set is obtained through the registration operation between the measurement data and the registration reference point set. Finally, based on the stability and reliability of important sampling sensitivity and statistical error, obtain the probability density function of error normal distribution statistics samples and important samples. The selection of statistical control points and the rationality of the objective function were verified. The stability/reliability of the statistical alignment point selection is proved to be feasible. The statistical registration deviation is [0.015,0.026] mm, and the ICP registration deviation is [0.031,0.035] mm. The average deviation of statistics registration is about 0.013 mm smaller than the average deviation of ICP registration. The deviation of statistical sampling points is about 0.0214 mm, and that of traditional sampling points is about 0.0275 mm. The deviation of statistical sampling points is about 0.0061 mm smaller than that of traditional sampling points. It meets the requirements of rapid, high efficiency and high precision measurement for aeroengine blades.