Blade Morphology Research Articles

Research on laser measurement point cloud preprocessing and 3D reconstruction technology for free-form surfaces

Surface morphology measurement and reconstruction technology based on point cloud data is one of the key technologies for 3D information processing in the digital manufacturing industry and has been widely applied in fields such as reverse engineering, computer vision, and unmanned driving system navigation. A method for 3D modeling of aircraft-engine blade profiles based on laser measurement point cloud data is proposed to address the difficulties in measuring the 3D morphology of aircraft-engine blades and the low modeling accuracy. This method first preprocesses the measured point cloud and then uses Poisson's algorithm to reconstruct the blade surface in three dimensions based on the calculation of the point cloud normal. Through error statistical analysis, the overall reconstruction effect is good. The experimental results further validated the generality and effectiveness of this method.

Prediction of Progressive Erosion Characteristics of Centrifugal Pump Blades Based on Dynamic Boundaries

Abstract The conventional method of fixed boundaries for predicting erosion inadequately reflects the erosion characteristics of centrifugal pumps under realistic operating conditions. In this research, we employ the dynamic boundary method, considering the influence of changes in wall morphology due to erosion on the flow field. We utilize the Euler-Lagrange approach and the E/CRC erosion model, incorporating a dynamic boundary geometry reconstruction strategy, to predict the erosion characteristics of the IS80-50-315 single-stage single-suction centrifugal pump. Solid-liquid two-phase flow calculations are conducted on the pump to predict erosion characteristics under varied operating conditions. The results show that the dynamic boundary-based progressive erosion prediction method realistically forecasts the erosion characteristics of the overflow wall and captures the evolution of blade morphology with erosion time. Erosion intensity on the blade suction surface significantly surpasses that on the pressure surface, guided by particle distribution characteristics in the centrifugal pump flow channel. Particle diameter primarily influences the erosion position of centrifugal pump blades; smaller particles induce erosion in the middle region of the blade, while an increase in particle diameter shifts the severe erosion position towards the impeller outlet direction. At a consistent particle diameter, higher particle concentrations correspond to elevated erosion rates in the blade area. We establish a relationship between the blade mass loss rate and erosion time during 2500 hours of pump operation at the design condition, introducing the blade mass loss rate for convenient assessment and prediction of blade damage in the centrifugal pump.

Correcting Hardening Artifacts of Aero-Engine Blades with an Iterative Linear Fitting Technique Framework.

Aero engines are the key power source for aerospace vehicles. Cermet turbine blades are the guarantee for the new-generation fighters to improve aero-engine overall performance. X-ray non-destructive reconstruction can obtain the internal structure and morphology of cermet turbine blades. However, the beam hardening effect causes artifacts in objects and affects the reconstruction quality, which is an issue that needs to be solved urgently. This study proposes a hardening-correction framework for industrial computed tomography (ICT) images based on iterative linear fitting. First, an iterative binarization was performed to improve the penetration length accuracy of the forward projection. Then, the proposed linear fitting technology combined with the Hermite function model is derived and analyzed to obtain suitable parameters of blade data. Finally, the fitting curves of the blade data, using the proposed method and the traditional polynomial fitting method, were analyzed and compared and were used to correct the engine turbine blade projection data to reconstruct different groups of tomographic images. Different groups of tomographic images were analyzed using three quantitative image quality evaluation indicators. The results show that the root-mean-square error (RMSE) of the tomographic image obtained by the proposed framework is 0.0133, which is lower than that of the compared method. The peak signal-to-noise ratio (PSNR) is 37.7050 dB and the feature structural similarity (FSIM) is 0.9881, which are both higher than that of the compared method. The proposed method improves the hardening-artifact-correction capability and can obtain higher-quality images, which provides new ideas for the development of imaging and detection of new-generation aero-engine turbine blades.

A frost ice formation method of horizontal axis wind turbine blade based on polynomial fitting

In this paper, a new direct calculation method of frost ice shape on the blade surface of horizontal axis wind turbine is proposed. Using linear interpolation algorithm, the airfoil ice shape obtained by LEWICE 2D software or ice wind tunnel experiment was fitted with equidistant step length in the first and fourth quadrants and equidistant step length in the second and third quadrants. The key point coordinates of ice shapes on cross-sections along the span-wise were mapped into lagging and flapping surfaces through the mathematical dimension reduction, respectively. The polynomial fitting was used to deal with ice projection points of multiple sections in lagging and flapping surfaces, and then the blade’s frost ice shape was obtained. By calculating the sum of squared residuals of the polar diameter at the same polar angle, the errors between experimental and airfoil frost shape fitting methods, experimental and FENSAP, and blade frost shape formation methods and FENSAP were analyzed. The results show that the new method is in good agreement with the ice shape of FENSAP simulation results and experimental results. The residual sum of squares is small. This method makes the analysis of frost ice morphology of wind turbine blades do not need to consider interdisciplinary. The calculation process is simple and reliable.

Determination of wear resistance of nickel-carbide alloy coating by atmospheric plasma spray technique on 30MnB5 alloy steel used in cultivator blades

The wear that occurs during tillage in agricultural machinery shortens the material’s life and increases costs. This study investigated the microstructure and morphology of cultivator blades coated with atmospheric plasma spray (APS) process and tested under real field conditions using OM, SEM, EDX, and XRD techniques. Abrasion tests were conducted in an area of 110 hectares and under two different soil moisture conditions. Material properties were investigated using hardness and surface roughness tests. The coating process was successful both mechanically and metallurgically by applying Ni-WC ceramic-metal (cermet) powder on the surface of 30MnB5 steel substrate with APS. The oxide and carbide structures detected on the coating surface by XRD studies resulted in a 1.5 times higher coating hardness. Due to the hard carbide phases in the coating matrix, the grooves on the wear surfaces were shallow and narrow compared to the substrate sample. The surface roughness values of the coated sample were approximately two times higher than the substrate sample. Due to the microstructure and high hardness, the coated specimen experienced three times less abrasion in both humidity conditions. The APS method can be successfully applied to the machined parts of tillage machines. In the near future, the cost of agricultural production can be reduced, and the environment can benefit from this method. In conclusion, this study presents a feasible approach to improving the wear resistance of Ni-WC ceramic-metal alloy by plasma spray coating under real field conditions.

A Review on Leading-Edge Erosion Morphology and Performance Degradation of Aero-Engine Fan and Compressor Blades

The leading edges of aero-engine fan and compressor blades suffer from severe erosion due to the inhalation of suspended particulates in the low-altitude atmosphere during long-term transport. A small deformation of the leading edge can significantly change the aerodynamic performance under a strong non-linear effect, leading to increased operation and maintenance costs for engines. This review first focuses on leading-edge erosion morphology during service, and models of these damages. Secondly, the performance degradation caused by eroded leading edges on different classes of engine components, including airfoils, blades, compression systems, and the whole engine, are reviewed. Finally, optimization methods for eroded blade leading edges and their effects on performance recovery are summarized. This paper contributes to an in-depth understanding of the erosion mechanism of blade leading edges in terms of status and its effect, and is a good reference for establishing erosion leading edge repair methods and improving the level of automated repair.

High precision structural light scanning viewpoint planning for aircraft blade morphology

High precision structural light scanning viewpoint planning for aircraft blade morphology

Aerodynamic Performance Analysis of Adaptive Drag-Lift Hybrid Type Vertical Axis Wind Turbine

In recent years, with the continuous development of new energy, how to efficiently use wind energy has received more and more market attention. Due to cost advantages, the development of small wind turbines is accelerating. Among them, the design and research of the airfoil design and research of the lift vertical axis wind turbine has matured, but because of the aerodynamic characteristics of the lift airfoil structure, it is impossible to start itself at low wind speed, resulting in the waste of low wind speed energy. Although the drag wind turbine has good self-starting performance, the wind energy utilization efficiency in the high-speed state is inefficient. Each has its own unique shortcomings, which directly affects the marketization of small wind turbines. In order to solve these problems, this paper presents a drag-lift hybrid type wind turbine structure based on an NACA0018 symmetrical airfoil, which can adaptively change the blade shape. This design can keep the blade in the drag shape under static and low speed conditions, and adaptively change the lift shape with the increase of speed. In addition, through the research method of CFD numerical simulation combined with physical experiments, the proposed wind turbine design is studied and analyzed from multiple angles. At the same time, the “6DOF + dynamic grid” setting is used to study the influence of the opening angle factor of the drag-lift hybrid blade on the self-starting performance, and the study shows that the design of the drag-lift hybrid blade proposed in this paper has a higher self-starting torque and lower starting wind speed than the traditional lifting blade, and it is observed that the drag-lift hybrid blade has the best self-starting performance when the opening angle of the blade is 80°. At the same time, the problem of switching the blade morphology of the drag-lift hybrid blade is also analyzed, along with how to use the spring to control all this adaptively. In order to better analyze the advantages of the drag-lift hybrid design proposed in this paper, a wind tunnel test was also carried out using the physical model, and the relationship between the leaf tip speed ratio and the wind energy utilization rate was obtained, which intuitively showed the improvement of the wind energy utilization rate of the drag-lift hybrid design compared with the traditional lift blade.

Alternative Method of Nature Inspired Geometrical Design Strategy for Drag Induced Wind Turbine Blade Morphology

Although drag driven wind turbine is regarded as an efficient rotor for low wind speed region, design reconfiguration is a continuous process in order to improve the performance of the rotor. The main governing factor that influences the performance of the rotor is the blade morphology. Hence, this paper presents a proposed nature inspired design approach for the development of drag driven wind turbine blade morphology. The design approach framework comprise of 3 main elements namely image processing, geometrical analysis and bio-hybridization. The proposed bio-hybridized design consist of blade mainframe curve inspired by nautilus shell and barnacle on the blade surface. It is found that integration of barnacle geometries on the surface of the blade has affected the performance of the rotor. Result shows that the peak Cm is at λ = 0.55 for experimental and CFD is Cm = 0.238 and Cm = 0.253 respectively. The proposed design resulted in experimental and numerical Cp = 0.113 and Cp = 0.127 respectively at 7 m/s and λ = 0.7. The presented design technique with appropriate design bio-element provides a systematic method for engineers to model wind turbine blade morphologies.

Mutagenic Effect of 60Co γ-Irradiation on Rosa multiflora 'Libellula' and the Mechanism Underlying the Associated Leaf Changes.

Gamma (γ)-irradiation can induce changes in plant morphology, cellular physiological activities, and genetic material. To date, there has been limited research on the molecular basis of leaf morphological abnormalities and physiological changes in irradiated rose plants. In this study, Rosa multiflora ‘Libellula’ plants were treated with 60Co γ-rays. The irradiation resulted in the distortion of blade morphology. Additionally, the leaf chlorophyll content decreased, whereas the accumulation of reactive oxygen species increased. The differentially expressed genes between the control and 2–3 plants irradiated with 50 Gy were analyzed by RNA-seq technology, which revealed genes related to chlorophyll metabolism were differentially expressed. The expression levels of genes related to the regulation of antioxidant enzyme synthesis were downregulated. An RNA-seq analysis also identified the differentially expressed regulatory genes involved in leaf morphology development. Four genes (RcYABBY1, RcARF18, RcARF9, and RcWOX8) were selected, and their expression patterns in different leaf development stages and in various plant organs were analyzed. Furthermore, virus-induced gene silencing technology was used to verify that RcYABBY1 is involved in the morphogenesis of R. multiflora ‘Libellula’ leaves. The results of this study are useful for clarifying the molecular, physiological, and morphological changes in irradiated rose plants.

The immature Homo naledi ilium from the Lesedi Chamber, Rising Star Cave, South Africa

Objectives Homo naledi is represented by abundant remains from the Dinaledi Chamber of the Rising Star Cave system in South Africa. While pelvic elements from the Dinaledi Chamber of the cave are fragmentary, a relatively complete ilium (U.W. 102a–138) was recovered from the Lesedi Chamber. We reconstructed and analyzed the Lesedi ilium, providing qualitative descriptions and quantitative assessment of its morphology and developmental state.Materials and MethodsWe compared the Lesedi ilium to remains from the Dinaledi Chamber, other South African hominin fossils, and an ontogenetic series of human ilia. We used the Dinaledi adults as a guide for reconstructing the Lesedi ilium. To assess development of the Lesedi ilium, we compared immature/mature proportional ilium height for fossils and humans. We used 3D geometric morphometrics (GMs) to examine size and shape variation among this sample.ResultsThe Lesedi ilium showed incipient development of features expressed in adult H. naledi ilia. The proportional height of the Lesedi ilium was within the range of human juveniles between 4–11 years of age. GM analyses showed that the Lesedi ilium had an iliac blade shape similar to those of australopiths and an expanded auricular surface more similar to humans.ConclusionsThe reconstructed Lesedi specimen represents the best preserved ilium of H. naledi, confirming the australopith‐like iliac blade morphology first hypothesized in adult specimens, and establishing that this anatomy was present early in this species' ontogeny. In contrast to australopiths, the Lesedi ilium displays an enlarged sacroiliac joint, the significance of which requires further investigation.

A whole-plant specimen of the marine macroalga Pterigophycos from the Eocene of Bolca (Veneto, N-Italy)

Uncalcified macroalgae are generally rare as fossils, and hence their past diversity and evolutionary history remain poorly resolved. The Bolca area in northern Italy has yielded abundant adpression fossils of Eocene macroalgae. However, the vast majority of specimens are detached blades and blade portions. Here, we present an almost complete thallus of the macroalga Pterigophycos from Bolca that consists of a squat holdfast from which leaf-like blades up to 30 cm long extend. Each blade has a midrib extending over its entire length. Proximally the lamina forms a narrow rim on each side of the midrib, but becomes wider and lobed in the lower mid-portion. In the upper three quarters of the blade the lamina consists of spathulate or wedge-shaped segments. Pterigophycos blades have certain features in common with the present-day Phycodrys rubens, Delesseria sanguinea (both Ceramiales, Rhodophyta), Undaria pinnatifida, and Egregia menziesii (both Laminariales, Phaeophyceae); however, the systematic affinity of the fossil remains unresolved. The fossil is suggestive of intraspecific variability in blade morphology, and thus contests the historic view that there are several different species of Pterigophycos in the Bolca flora.

Taxonomic Revision of Hook-Forming Acrosorium (Delesseriaceae, Rhodophyta) from the Northwestern Pacific Based on Morphology and Molecular Data.

Cosmopolitan Acrosorium species with hook-forming thalli have been merged under the name of Acrosorium ciliolatum (Harvey) Kylin through a long and complicated nomenclatural history. We examined the specimens of ‘A. ciliolatum’ and related taxa from the northwestern (NW) Pacific, the UK, southern Spain, Australia, New Zealand, and Chile, using morphological and molecular analyses. We confirmed that these specimens are separated into four clades based on rbcL phylogeny, and the absence or presence of terminal hook-like structures represent intraspecific variation. Our results indicated that Acrosorium flabellatum Yamada, Cryptopleura hayamensis Yamada, Cryptopleura membranacea Yamada and the entities known as ‘A. ciliolatum’ in the NW Pacific are conspecific; the name A. flabellatum is the oldest and has priority. This taxon exhibits extreme variations in external blade morphology. We also confirmed that the position of the tetrasporangial sori is a valuable diagnostic characteristic for distinguishing A. flabellatum in the NW Pacific. We also discussed the need for further study of European and southern hemisphere specimens from type localities, as well as the ambiguous position of California specimens.

Chemophenetics as a Tool for Distinguishing Morphotypes of Annona emarginata (Schltdl.) H. Rainer.

Annona emarginata (Annonaceae) has two morphological variations (A. emarginata 'mirim' and A. emarginata 'terra-fria'). The species has agricultural value and produces specialized metabolites of pharmacological interest. The objective of this work was to analyze whether chemical and morphological differences contribute to differentiate A. emarginata 'terra-fria' from A. emarginata 'mirim', as chemophenetic variations of A. emarginata. The analysis of chemical compounds was based on the quantification, profile of root alkaloids and on the leaves volatile profile, together with morphometric analyses of the leaf blade. The samples were collected in three phenological stages (flowering, fruiting, and vegetative) at two places in São Paulo, Brazil. Differences in the composition of the alkaloid profile and leaf volatiles (in both places and in the three phenological stages) allowed us to separate the two morphotypes by multivariate statistical analysis. These differences agreed with the leaf blade morphology and flower color. This first chemophenetic report of A. emarginata demonstrates that, in addition to morphological variations, the specialized metabolism of roots and leaves can be phytochemical characters, which suggest the existence of at least morphochemotypes of A. emarginata.

Study of √2 Conjecture in the Construction of Drag Induced Wind Turbine Blade Morphology

In wind engineering, the morphology of the turbine blade system governs the effectiveness in harvesting wind energy. The flow field response is the result of the turbine blade shape interaction with flow. Hence, mathematically interpreting the shape of the blade will help to understand the principals and properties of the utilized geometry for the blade construction. In this study, semicircle geometry of Savonius wind turbine blade is mathematically analyzed in order to understand its fundamental building block. We provide discussion on √2 conjecture found in the construction of circles, Fibonacci and Pythagoras spiral in relations to √2, √2 + 1 and √2 + 2. It is found that √2 conjecture can be utilized in determining the geometrical properties of circle and spiral. We also performed thorough assessment of the proposed conjecture to prove its robustness and reliability. The proposed conjecture is adapted to construct the blade morphology of drag induced wind turbine. CFD analysis is carried out to investigate the aerodynamic properties namely moment coefficient (Cm) of the constructed wind turbine shape via the proposed conjecture. Results shows that the proposed shape constructed based on the conjecture has improved Cm by 7.2 % at λ = 0.59 and 4 % at λ = 0.94 compared to conventional SWT

An approximation method combined with conformal transformation for the fast measurement of blade section curves

To realize high-precision machining of free-form blade surfaces, it is necessary to measure and reconstruct the blade morphology several times. Sampling measurements and data compression through free-curve approximation technology are of great benefit in shortening the processing time. A novel B-spline approximation method is proposed in this paper, which can determine a few dominant points based on curvature characteristics to approximate dense and noisy measured points with high precision. We adopt a unique adaptive knot placement strategy combined with a curvature dependent evaluation parameter and a conformal transformation method. This strategy is error-bounded in the initial knot placement, which greatly reduces the time consumed by subsequent iterative insertions. The proposed method shows advantages in approximation accuracy, compression rate, and especially in computational efficiency, in comparison with four traditional knot placement methods. Experiments were carried out and the results show that the dominant point selected by this method can replace the fine measurement results, and the compression rate of the measurement points can reach more than 90%. This method is suitable for the sampling measurement and compression of the data of blades, aircraft wings, and other similar free-form surfaces, and is especially suitable for solving the inefficiency problem caused by repeated measurements made in the process of iterative machining of aero-engine blades.

Novelties in Lepidaploinae (Asteraceae, Vernonieae) from the easternmost campos rupestres of Minas Gerais, Brazil: two new species and a range expansion

Background – Recent collection efforts in Serra do Padre Ângelo, Pico da Aliança, and Sete Salões State Park, all located in the state of Minas Gerais, have uncovered many botanical and zoological novelties. The region is an outlying campos rupestres area inserted in the Atlantic Forest phytogeographic domain, with its flora mostly related to that of the core campos rupestres area in the Espinhaço Range. Three species of Asteraceae, one of the most representative families in the campos rupestres, have been recently described for the area. Here we report two new species from the genera Lepidaploa and Lessingianthus and one range extension in Lessingianthus, both from subtribe Lepidaploinae.Methods – This study was based on specimens from the herbaria HUFU, MBML, SPF, UFP, and on field observations. Morphological observations and measures were taken following standard practices. Preliminary conservation assessments are based on field observations and spatial analyses (i.e. extent of occurrence, area of occupancy), following IUCN guidelines and criteria.Results – Two new species are described: Lepidaploa campirupestris, related to Lepidaploa aurea, differing from the latter by leaf indumentum, pedunculate heads, and number of florets; and Lessingianthus petraeus, related to Lessingianthus adenophyllus, but differing by leaf position and leaf blade morphology. We also report a range extension for Lessingianthus squamosus, previously known only for the state of Espírito Santo, ca 200 km away. Our results shed light on the interesting biogeography of the region, which mostly contains components of other campos rupestres areas intermixed with typical inselberg vegetation. It also highlights the importance of compiling floristic inventories in poorly collected localities and the need for conservation strategies for this biodiverse region.

<strong>A broadly sampled 3-loci plastid phylogeny of <em>Atraphaxis</em> (Polygoneae, Polygonoideae, Polygonaceae) reveals new taxa: II. <em>Atraphaxis</em> <em>selengensis</em> <em>spec. nov.</em>, and <em>A. davurica</em> Jaub. & Spach from Russian Transbaikalia</strong>

Maximum Likelihood (ML) and Bayesian analyses (BI) applied for 3-plastid loci (cpDNA trnL(UAA) intron, trnL–trnF IGS, and rpl32–trnL(UAG) IGS regions) / 55 tips of Atraphaxis revealed a subclade of two endemics from Transbaikalia (Dahuria) which are often mistaken for A. pungens and A. frutescens but phylogenetically distant from both. Atraphaxis selengensis is a species new to science which inhabits dune sands along the Selenga and Chikoy rivers and has specific morphology of perianth, fruits, ochreas, leaf blades, and pollen. Atraphaxis davurica inhabits stony mountain steppe in Buryatia and Chita region and differs from A. pungens and A. frutescens by longer ochreas, fruits, styles and stigmas extended to ends. Two varieties recognized by Ledebour in plants from Russian Transbaikalia have no clear morphological and molecular distinctions, but the plants from Khentei-Chikoy Highlands subtly differ in leaf ratio (length/width), bark colour, and a single-nucleotide substitution in trnL–F region. These plants are described as A. davurica var. chikoensis var. nov. Morphological descriptions of A. selengensis and A. davurica are supplied with LM and SEM images and a distributional map. Atraphaxis frutescens and A. pungens are absent from Russian Transbaikalia but distributed in Altai, Tuva, Khakassia, Mongolia and China.

A review on the prospect of wind power as an alternative source of energy in Malaysia

Fossil fuels has dictated the energy sector for several decades, rising as the primary and prominent source of energy production for various sector of industries namely electricity (power), transportation, manufacturing and others. However, extensive usage of fossil fuels majorly contributed to pollution issues and degradation of the environment. Hence, governments and research agencies are providing supports and resources to facilitate the growth of renewable energy sector (RES). This manuscript provides a brief view of the challenges of wind renewable energy sector in Malaysia relative to geographical wind condition, government policies and challenges in initiation of wind technologies and global perspective of green energy in terms of RER. It is found that data presented by previous researchers on wind speed data are considered unreliable to be utilized for WT power density assessment and design. Notably, wind speed in Malaysia is seasonal based and highly inconsistent. The wind flow pattern and intensity experience by Malaysia are merely an aftereffect of weather change in neighbouring regions. Nevertheless, it is found that selected regions of east-coast peninsular Malaysia and selected region of Sabah and Sarawak is potential for harvesting wind power due to substantial and adequate wind pattern behavior during monsoon season. Therefore, it is evident that geographical wind condition of Malaysia is appropriate for wind power devices as a form of RER in green energy sector of Malaysia. However, it is also found that fundamental design modification is required on conventional design of WT in terms of blade morphology and configuration in order to adapt to unsteady monsoon wind speed pattern.

Changes in leaf blade morphology and anatomy caused by clomazone and saflufenacil in Setaria viridis, a model C4 plant

Clomazone and saflufenacil are herbicides extensively used worldwide to weed control. We studied the effects of these two herbicides on morphoanatomical parameters of Setaria viridis. Plants were sprayed with four concentrations of each herbicide (clomazone: 500, 1000, 1500 and 2000 g of active ingredient (ai) ha−1 and saflufenacil: 49, 98, 147 and 196 g ai ha−1) besides control (without spraying) 20 days after transplantation. The experimental design was completely randomized with five replicates per treatment. Pigment content, visible injuries, morphological and ultrastructural changes were evaluated. No signs of tolerance to either of the tested herbicides were observed. Clomazone caused a decrease in photosynthetic pigment content over time, mostly in young leaves, leading to an “albino” like appearance. There was a reduction in the number of grana in the chloroplasts of mesophyll cells (MC) in necrotic areas. Saflufenacil reduced chlorophyll content, impairing energy absorption in the antenna complex. Injuries to foliar tissues, such as necrosis and depigmentation, were visible as early as 24 h after herbicide application. Bundle sheath chloroplasts (BSC) and MC were completely deformed. The data support the use of S. viridis as a model plant for studies on herbicide effects in C4 monocots.