Optimum Solidity on Downwind Thai Sail Windmill

Solidity was a significant parameter affecting the efficiency of wind turbines. It is defined as the ratio between the projected area of all blades and the swept area of the rotor. The solidity could be improved by modifying the shape, cord length, or the number of blades. Research studies mentioned that higher solidity seemed to provide more power due to more blade area. However, it can be argued that if the solidity was too high, it would cause the airflow to be more obstructed and disrupted, causing the gained power to drop down instead. Thus, the optimum solidity, which made the wind turbines maximum effective, must be existent in itself and must be in the range between 0 - 100 %. Thai sail windmill is a kind of horizontal axis wind turbine currently used to pump seawater in salt farms in Thailand, where the general solidity is in the quite wide range of about 15 - 60 %. Mostly, the Thai sail windmill was designed by a rule of thumb. Hence, it has quite a low efficiency, which is only about 10 %. This study aims to investigate the optimum solidity of Thai sail windmill in the downwind type to enhance efficiency. The 4-blade and 6-blade rotors of 1-m radii were used as the prototypes for experiments using the tow testing method. The results showed that the optimum solidity of 4-blade and 6-blade rotors was 28 %, respectively, whereby the maximum efficiency of the 2 rotors was 17 and 25 %.

INVESTIGASI ALIRAN PADA THRUSTER ROV (REMOTELY OPERATED VEHICLE) MENGGUNAKAN METODE CFD

Remotely Operated Vehicle (ROV) is an underwater robot that designed by UNTAR Robotics Team and has been competed in Singapore Robotics Games (SRG) 2020. Evaluation that conducted from the competition is the need of optimization in thrust and maneuverability so it can move more flexible and stable. Based on the problem, investigation of thruster’s configuration by adding kort nozzle to existing propeller is implemented to increase thrust and performance. Consideration in using open water characteristics for analysis is elaborated in this investigation. The existing propeller has 3-blade with 35 mm diameter; 1,4 pitch diameter ratio; and 0,511 expanded blade area ratio which is used as thruster of ROV 2020. It utilizes CFD approach in ANSYS CFX 2020 R1 software with moving reference frame (MRF) method. Meanwhile, general mesh or unstructured mesh arrangements is used as computational mesh with 165.201 nodes. The MRF implements frozen rotor concept as frame change/mixing to observe fluid flow. The CFD with shear stress transport (SST) k-omega model is conducted. The simulation is done at 300 rpm and J = 0,473 for ROV’s operating condition. The result shows that thruster equipped by kort nozzle is able to increase the thrust for 2,253% and reduce the propeller required torque for 6,633%. Furthermore, the configuration can also reduce wake phenomenon as result of rotating propeller which represents better maneuver chance. Keywords: ROV, kort nozzle, open water characteristics, CFD, performanceAbstrakRemotely Operated Vehicle (ROV) merupakan sebuah underwater robot yang didesain oleh Tim Robotik UNTAR dan telah berkompetisi dalam Singapore Robotics Games (SRG) 2020. Evaluasi yang dilakukan terhadap hasil kompetisi tersebut adalah terdapat kebutuhan untuk melakukan optimasi dalam thrust dan kemampuan bermanuver sehingga ROV dapat bergerak lebih fleksibel dan stabil. Berdasarkan permasalahan tersebut, investigasi pada konfigurasi thruster dengan penambahan kort nozzle terhadap existing propeller diimplementasikan untuk meningkatkan thrust dan unjuk kerja. Pertimbangan dalam penggunaan open water characteristics sebagai dasar analisis diuraikan dalam investigasi ini. Existing propeller memiliki 3 buah blade dengan diameter 35 mm; pitch diameter ratio sebesar 1,4; dan expanded blade area ratio sebesar 0,511 yang mana digunakan sebagai thruster ROV 2020. Investigasi tersebut menggunakan pendekatan CFD dalam software ANSYS CFX 2020 R1 dengan metode moving reference frame (MRF). Sementara itu, computational mesh menggunakan jenis general mesh atau unstructured mesh arrangements dengan total 165.201 nodes. MRF mengimplementasikan konsep frozen rotor sebagai frame change/mixing untuk mengamati aliran fluida. CFD dilakukan dengan menggunakan model shear stress transport (SST) k-omega. Simulasi tersebut dilakukan pada 300 rpm dan J = 0,473 sebagai operating condition ROV. Hasil simulasi menunjukkan bahwa thruster yang dilengkapi kort nozzle mampu meningkatkan thrust sebesar 2,253% dan mengurangi torsi yang dibutuhkan propeller sebesar 6,633%. Lebih lanjut, konfigurasi ini juga dapat mengurangi fenomena wake sebagai akibat dari putaran propeller yang mana merepresentasikan peluang manuver yang lebih baik.

Application of the Adobe Photoshop Software Package in Leaf Blade Area Measurement of Woody Plants

There are a number of applied methods for determining morphometric parameters, including the area of leaf blades of woody plants: millimeter graph paper method, method of direct measurements, punching method, and planimetric method. The analysis and practical application of the methods in the test mode revealed their shortcomings related to inaccuracy of measurements, experiment duration, and equipment inaccessibility. Many researchers have successfully acquired digitized images. However, capturing the parameters of the considered structure from the monitor screen is often impossible due to the low availability of morphometric programs and their high cost. The purpose of the work is to evaluate the effectiveness of existing methods for determining the area of leaf blades on the example of the birch genus (Betula L.) trees and to accumulate the algorithm for determining morphometric parameters of birch leaf blades in the Adobe Photoshop software package. We have developed a method for determining morphometric parameters of leaf blades of woody plants using the Adobe Photoshop software package. The research subject is the leaf blades of birch trees. This method requires: blank A4 sheets; a ruler with an angle of 90°; transparent adhesive tape (scotch tape); and a scanner. We draw a reference square of random (but fixed) dimensions in a random corner of each sheet, step by 10 mm from its borders, on a blank A4 sheet using a ruler with an angle of 90°. The square is placed strictly parallel to the sheet borders. Then, leaf blades of the desired wood species are attached to the sheet with scotch tape. Using the scanner, we convert the workpiece into electronic form and upload the image to Adobe Photoshop. In order to receive morphometric parameters, you can use the following program tools: “ruler”, “magic wand”, “magnetic lasso tool”. At the same time, it is possible to automatically select the borders of the studied object, which helps to avoid subjective errors. The resulting measurements are displayed in pixels and then converted to the required units. The obtained data is verified using the reference square. Verification showed that the method accuracy is more than 99.9 %. The proposed method allows to perform fast and accurate measurements of morphometric parameters of leaf blades, without requiring the purchase of expensive equipment, which makes it available to any researcher who faces with the task of measuring the surface of leaf blades of woody plants. For citation: Babaev R.N. Application of the Adobe Photoshop Software Package in Leaf Blade Area Measurement of Woody Plants. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 5, pp. 185–191. DOI: 10.37482/0536-1036-2021-5-185-191

WEAR OF THE RIGHT KNIFE OF THE PSKU SPEED PLOW AND TECHNOLOGICAL MEASURES TO INCREASE ITS DURABILITY

The intensification of crop production has led to the creation of equipment for high-speed tillage. The high speed of plowing causes an increased intensity of wear of the working bodies of plows. The limit capacity of the vertical knife when processing loamy soils is about 30 hectares, after which the body must be subjected to repair (maintenance) operations. (Research purpose) The research purpose is in studying the wear of the right knives of the PSKU plow (geometry and location on the working surface), assessing the technical condition and develop measures to improve their durability. (Materials and methods) The right knife (plowshare) performs the function of a pruning element, its design corresponds to the design of the plowshare in the classic version, but with reduced dimensions. We carried out wear control in width and thickness on 14 parts. (Results and discussion) The knives after working 30 hectares are suitable for further use in width. The width of the solid layer deposited on the back side is about 7-8 millimeters, so additional surfacing of the abrasive-resistant alloy is necessary. The wear on the thickness of the knife cannot be the reason for its decommissioning, since the strength and rigidity are preserved, and the agrotechnical requirements for soil cultivation are not violated. (Conclusions) The residual width and thickness of the studied knives when plowing loam retain the normalized limits, which indicates the possibility of their further operation, but it is necessary to weld the cutting-blade part from the back with an abrasive- resistant alloy. The xiphoid wear is fused with an electrode that provides a roller hardness of about 50 HRC. A low level of wear rate of the part is achieved due to the hardness of the blade area 60 HRC.

Growth, development and yield of beet varieties under the action of biological products

The search for new conditions for growing vegetables in organic crops in order to obtain safe products and in connection with changes in climatic conditions requires an immediate solution. The article considers and proves that the use of biological products affects the formation of highly productive crops and promotes the production of products with a high content of biologically active substances. Studies have shown a positive effect of biological products on the growth and development and yield of beetroot varieties Delicatessen and Red Ball. Studies have been conducted to study the technological aspects of growing vegetables, in particular with the use of biological products, taking into account the environmental impact of both growth processes and quantitative and qualitative indicators. Features of various biological products and their efficiency are analyzed. A comparative analysis of the use of biologicals, which allowed to comprehensively assess the impact of elements of cultivation technology on phenological, biometric, indicators, yield and quality of table beet products, development and improvement of elements of technology for their cultivation in the forest-steppe of Ukraine. This involves the use of highly productive varieties, the use of various effective biological products, is relevant for the spread and cultivation of table beets in the forest-steppe of Ukraine. Phenological observations of canteen beet plants showed that they developed differently and reacted differently in the phases of growth and development, depending on the introduced biological products. The technical ripeness phase began on days 121–129 and was longer than in the control. With the introduction of Solutin and Chlorella – 128–129 days, and in short - with the introduction of biological products Helprost vegetable, Helprost vegetable + Phytohelp, Solutin + Phytohelp – 121–125 days. It was proved that table beet plants differed in height, number of leaves, leaf blade area and their total area per hectare, which compared to the control were from the use of a tank mixture of biological products Helprost vegetable + Phytohelp – 28.3–28.7 thousand m2/ha, which is significantly higher than the control by 13.6–14.8 thousand m2/ha. The area of leaves was slightly lower as a result of the use of other drugs and mixtures – 21.8–22.6 thousand m2/ha. The use of a mixture of drugs Helprost vegetable + Phytohelp contributed to an increase in the mass of the root of table beets by 255–350 g, which is significantly higher than the control by 9–10 g. A positive effect on the yield of beetroot was shown by the vegetable Helprost preparation, as well as a mixture of vegetable Helprost + Phytohelp preparations, the use of which provided a yield of 52.4–63.8 t/ha. The use of a mixture of biological products Solutin + Phytohelp improves the appearance of the plant, increases resistance to harmful microorganisms, and the marketable yield increases to 26.0 t/ha and significantly exceeds the control by 3.2 t/ha.

Feasibility Study on the Effect of Blade Inclination for Heavy Duty Centrifugal Fans – Aerodynamic Aspects

With a special focus on the industrial feasibility and the manufacturability, a recently proposed novel approach to centrifugal impeller blade inclination is adopted and investigated through extensive CFD analysis. The fan blades, originally aligned perpendicular to the impeller backplate, are inclined in either forward or backward direction. For the presented study, an industrially proven fan design is chosen for testing. Compared to the original design, the inclined fan blades possess an increased total blade area and at the same time providing variable inflow angles at the leading edges of the blades. These two factors are expected to alter the fan characteristic curves in providing an increased range of optimum performance while maintaining high aerodynamic efficiency. The results obtained show a clear trend in aerodynamic performance with the degree of inclination, where the characteristic curves rotate at about the design point, allowing local improvements either at overload conditions or part-load conditions of the fan. Moreover, the trends obtained show the tendency to agree well with the rudimentary models published in previous studies, even though it appears to be affected by the fan volute and the point of operation as well.

Effect of water depth on eight varieties of rice in Obukiyo, Oju lga of Benue state, Nigeria

Water depth has been described as one of the most important environmental factors determining the growth and yield of rice. Different rice varieties respond differently to various water levels. Three (3) naturally existing water levels (5cm, 10cm and 15cm) at Obukyo Oju Local Government Area of Benue State were studied to evaluate their impact on eight varieties of rice (FARO 15, 37, 44, 52, 57, 60, 61 and 62). The data collected showed significant different (P< 0. 05) in plant height, blade area, panicle length and dry seed weight, while the number of leaves and tillers were not significantly affected by the various water levels. Generally, the rice performed better in high water levels (15cm) than the medium (10cm) and low water depth (5cm). FARO 57 (9.86t/ha), FARO 61(9.86t/ha), FARO15 (8.78t/ha) and FARO 52 (8.28t/ha) were significantly higher while FARO 44 (5.24t/ha) the dwarf variety and FARO 37 (5 54t/ha) the lodging and low drought resistance variety yielded very poor in high and medium water levels but encouragingly high in low water depth. FARO 57 (5.75t/ha) and FARO 60 (5.65t/ha) were the lowest in low water levels. FARO 15, 52, 57, 60, 61 and 62 were recommended for high water levels while FARO 15, 52, 57, 60, 61 and 62 were recommended for medium water levels. FARO15, 37, 44, 52, 61 and 62 are recommended for low water level. FARO 15, 52, 61 and 62 had encouraging yield in all water levels and are recommended as such.

Neural network integration in the analysis, selection of wageningen’s b-series ship propeller

In the preliminary stage, ship design analyzes and evaluates the close correlation and interaction fit between the hull, main engine, and propulsion. Therefore, the process of calculation and selection of the appropriate propulsion device plays the role of ensuring the necessary propulsion to achieve the design speed according to the mission and ensuring the appropriate torque of the main engine to achieve optimal performance. According to the traditional approach, the propeller design method is based on series B - Wageningen's experimental graph to determine the suitable diameter and geometric parameters. This paper presents the method of integrating the neural network algorithm in the preliminary design stage to support selecting the appropriate blade area ratio from input parameters, including the ship length, displacement, design speed, and the number of propeller blades. The neural network principle is to synthesize the reference result from the propeller database's individuals to give the appropriate blade area ratio with the closest probability in the database, taking into account cavitation. In this study, the B-Wagenningen series propeller design database is verified and applied well in practice. On that basis, the propeller geometry parameters are proposed from the neural network algorithm, and the thrust and torque coefficients are calculated and verified based on computational analysis from commercial software.

Performance modelling of the Darrieus wind turbine

Three-dimensional numerical investigation of the Darrieus wind turbines equipped with different aerofoils is presented in this paper. In the modelling, the computational domain was divided into three different domains and they are blade, rotor, and tunnel domains. A cylindrical domain was created to cover the blade area so that a fine mesh can be applied. The Computational Fluid Dynamics (CFD) was employed to solve and analyze the flow field around the turbine. The Menter Shear Stress turbulence model was chosen in this investigation. Boundary conditions applied were velocity at the inlet, pressure opening at the outlet, and symmetry on other sides. Comparison of simulation results and experiments showed good agreement. The investigation of the effects of the rotor solidity and the aerofoil shape was performed. The simulation results reveal that the aerofoil shape has a significant impact on the turbine performance. For the rotor solidity of 0.7, the change from the NACA section to the S1046 leads to a reduction of power at low tip speed ratios but the performance improvement is observed when the tip speed ratio is greater than 1.5. With the lower solidity of 0.375, the effects of the aerofoil change is less pronounced at low tip speed ratios. Nevertheless, the maximum power coefficient increases for both cases. Further analysis shows that the S1046 is less sensitive to the wind speed change and is promising in the urban application where the wind speed is relatively low.

Botanical Digitization: Application of MorphoLeaf in 2D Shape Visualization, Digital Morphometrics, and Species Delimitation, using Homologous Landmarks of Cucurbitaceae Leaves as a Model

ABSTRACTMorphometrics has been applied in several fields of science including botany. Plant leaves are been one of the most important organs in the identification of plants due to its high variability across different plant groups. The differences between and within plant species reflect variations in genotypes, development, evolution, and environment. While traditional morphometrics has contributed tremendously to reducing the problems that come with the identification of plants and delimitation of species based on morphology, technological advancements have led to the creation of deep learning digital solutions that made it easy to study leaves and detect more characters to complement already existing leaf datasets. In this study, we demonstrate the use of MorphoLeaf in generating morphometric dataset from 140 leaf specimens from seven Cucurbitaceae species via scanning of leaves, extracting landmarks, data extraction, landmarks data quantification, and reparametrization and normalization of leaf contours. PCA analysis revealed that blade area, blade perimeter, tooth area, tooth perimeter, height of (each position of the) tooth from tip, and the height of each (position of the) tooth from base are important and informative landmarks that contribute to the variation within the species studied. Our results demonstrate that MorphoLeaf can quantitatively track diversity in leaf specimens, and it can be applied to functionally integrate morphometrics and shape visualization in the digital identification of plants. The success of digital morphometrics in leaf outline analysis presents researchers with opportunities to apply and carry out more accurate image-based researches in diverse areas including, but not limited to, plant development, evolution, and phenotyping.