Journal articles: 'Solidity ratio'

1

Zawadzki, Karol, Wojciech Śmiechowicz, Małgorzata Stępień, Anna Baszczyńska, and Michał Tarkowski. "Influence of the Solidity Ratio on the Small Wind Turbine Aerodynamics." E3S Web of Conferences 242 (2021): 03006. http://dx.doi.org/10.1051/e3sconf/202124203006.

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Increasing popularity of individualised electricity generation from wind by prosumers creates a strong demand for profitable and highly efficient small wind turbines. This paper investigates the influence of rotor blade solidity parameter on device efficiency in hope of determining its optimal value as a part of the development process of the GUST small wind turbine. The study involved experimental analysis in the wind tunnel and numerical simulations performed in QBlade software. Different solidities of the rotor were achieved by alteration of (1) number of blades and (2) chord distribution along the blade span. The increase of rotor solidity resulted in augmentation of the aerodynamic efficiency in both approaches. The elongation of the chord by 33% in a 3-bladed rotor resulted in a bigger power coefficient increment than addition of a 4th blade with original chord distribution. Even though the solidity was the same, the 3-bladed rotor performed better, possibly due to lower form drag. The results emphasize the importance of the rotor solidity optimization during the small wind turbine rotor development and may significantly influence overall power output.

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Nakagawa, Koji, Hiroshi Hayami, and Yuichi Keimi. "Comparison of Two Diffusers in a Transonic Centrifugal Compressor." International Journal of Rotating Machinery 9, no. 4 (2003): 279–84. http://dx.doi.org/10.1155/s1023621x03000253.

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Flow mechanisms suppressing the flow separation in two diffusers, a low-solidity cascade diffuser and a vaned diffuser with additional small vanes near the inlet, were compared mainly by numerical simulation. As the superiority of the low-solidity cascade diffuser was expected, a series of experiments was conducted using a transonic centrifugal compressor with a maximum pressure ratio of 7. The performance of the compressor with the vaned diffuser was comparable to that of the low-solidity cascade diffuser only between the surge point and the design flowrate at a pressure ratio of 3.5. The maximum flowrate of the vaned diffuser was lower than that of the low-solidity cascade diffuser. At higher rotational speeds, the pressure ratio at the surge point, the efficiency, and the flow range of the low-solidity cascade diffuser exceded those of a vaned diffuser at a pressure ratio of 3.5.

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Cui, Ying, and Zhen Liu. "Effects of Solidity Ratio on Performance of OWC Impulse Turbine." Advances in Mechanical Engineering 7, no. 1 (December 23, 2014): 121373. http://dx.doi.org/10.1155/2014/121373.

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Castellano, S., A. Candura, and G. Scarascia Mugnozza. "RELATIONSHIP BETWEEN SOLIDITY RATIO, COLOUR AND SHADING EFFECT OF AGRICULTURAL NETS." Acta Horticulturae, no. 801 (November 2008): 253–58. http://dx.doi.org/10.17660/actahortic.2008.801.24.

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Oliveira, Pedro, Marion Alliet, Carole Coufort-Saudejaud, and Christine Frances. "New insights in morphological analysis for managing activated sludge systems." Water Science and Technology 77, no. 10 (April 26, 2018): 2415–25. http://dx.doi.org/10.2166/wst.2018.189.

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Abstract In activated sludge (AS) process, the impact of the operational parameters on process efficiency is assumed to be correlated with the sludge properties. This study provides a better insight into these interactions by subjecting a laboratory-scale AS system to a sequence of operating condition modifications enabling typical situations of a wastewater treatment plant to be represented. Process performance was assessed and AS floc morphology (size, circularity, convexity, solidity and aspect ratio) was quantified by measuring 100,000 flocs per sample with an automated image analysis technique. Introducing 3D distributions, which combine morphological properties, allowed the identification of a filamentous bulking characterized by a floc population shift towards larger sizes and lower solidity and circularity values. Moreover, a washout phenomenon was characterized by smaller AS flocs and an increase in their solidity. Recycle ratio increase and COD:N ratio decrease both promoted a slight reduction of floc sizes and a constant evolution of circularity and convexity values. The analysis of the volume-based 3D distributions turned out to be a smart tool to combine size and shape data, allowing a deeper understanding of the dynamics of floc structure under process disturbances.

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McFarlane, Caroline M., and Alvin W. Nienow. "Studies of high solidity ratio hydrofoil impellers for aerated bioreactors. 1. Review." Biotechnology Progress 11, no. 6 (November 1995): 601–7. http://dx.doi.org/10.1021/bp00036a001.

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Chaudhary, Manoj Kumar, and Anindita Roy. "Design & optimization of a small wind turbine blade for operation at low wind speed." World Journal of Engineering 12, no. 1 (February 1, 2015): 83–94. http://dx.doi.org/10.1260/1708-5284.12.1.83.

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A small wind turbine blade was designed and optimized in this research paper. The blade plays an important role, because it is the most important part of the energy absorption system. Consequently, the blade has to be designed carefully to enable to absorb energy with its greatest efficiency. The main objective of this paper is to optimized blade number and selection of tip speed ratio corresponding to the solidity. The power performance of small horizontal axis wind turbines was simulated in detail using blade element momentum methods (BEM). In this paper for wind blade design various factors such as tip loss, hub loss, drag coefficient, and wake were considered. The design process includes the selection of the wind turbine type and the determination of the blade airfoil, twist angle distribution along the radius, and chord length distribution along the radius. A parametric study that will determine if the optimized values of blade twist angle and chord length create the most efficient blade geometry. The 3-bladed, 5-bladed and 7-bladed rotor achieved maximum values of Cp 0.46, 0.5 and 0.48 at the tip speed ratio 7, 5 and 4 respectively. It was observed that using BEM theory, maximum Cp varied with strongly solidity and weakly with the blade number. The studies showed that the power coefficient increases upto blade number B = 5, while the blade number if increased above 5 then the power coefficient decreases at operating pitch angle equal to 3°. Highest Cp would have solidity between 4% to 6% for number of blade 3 and design point tip speed ratio of about "7". Highest Cp would have solidity ranging from 5% to 10% for number of blade 5 and 7 and design point tip speed ratio of about 5 and 4 respectively.

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Ghiasi, Pedram, Gholamhassan Najafi, Barat Ghobadian, and Ali Jafari. "Analytical and Numerical Solution for H-type Darrieus Wind Turbine Performance at the Tip Speed Ratio of Below One." International Journal of Renewable Energy Development 10, no. 2 (December 30, 2020): 269–81. http://dx.doi.org/10.14710/ijred.2021.33169.

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H-type Darrieus vertical axis wind turbines (VAWT) have omnidirectional movement capability and can get more power compared to other VAWTs at high tip speed ratios (𝜆). However, its disadvantages are self-starting inability and low generated power at 𝜆 less than 1. The performance of H-type Darrieus wind turbine at 𝜆<1 was studied using double multiple stream tube (DMST) model and two-dimensional computational fluid dynamic (CFD) simulation. In CFD simulation, the Unsteady Reynolds Averaged Navier-Stokes (URANS) equations were used and the turbulence model was solved with SST k-ω model. The performance of fifteen various wind turbines was determined at fourteen wind velocities by two solution methods. The effect of chord length, solidity, Reynolds number and Height to Diameter (H/D) ratio were investigated on generated torque, power and the time required to reach 𝜆=0.1. Increasing in the moment of inertia due to the increasing in required time to reach 𝜆=0.1. In the low TSRs, the wind turbines can generate higher torque and power in high Re numbers and solidities. The required time was reduced by an increase in Re number and solidity. Finally, the best ratio of H/D of H-type Darrieus wind turbines was defined to improve the turbine performance.

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Rasekh, Sepehr, and Saeed Karimian. "Effect of solidity on aeroacoustic performance of a vertical axis wind turbine using improved delayed detached eddy simulation." International Journal of Aeroacoustics 20, no. 3-4 (March 25, 2021): 390–413. http://dx.doi.org/10.1177/1475472x211003299.

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Vertical axis wind turbines (VAWTs) can be suitably installed in urban regions. Although the power performance is essential, the noise generated by a VAWT may influence the living environment. An accurate prediction of power and noise performance is therefore necessary. In the present study, a precise aerodynamic and aeroacoustic performance assessment of a Darrieus VAWT is accomplished with the aim of exploring the effect of solidity parameter using a high-fidelity method. The improved delayed detached eddy simulation (IDDES) and the Ffowcs Williams and Hawkings (FW-H) acoustic analogy approaches have been utilized for predicting flow field and noise level. The simulations were performed in three different solidities at a specific tip speed ratio (TSR). It is shown that changing the solidity parameter affects both power and noise level remarkably. Change in the aerodynamic performance mostly occurs due to variation in instantaneous effective angle of attack which comprises many detailed discussions. The lower the solidity the higher the value of effective angle of attack. The noise level also affects by changing solidity as consequence of flow field variation. It is discussed here how the noise level would alter in terms of solidity, TSR, distance and azimuth angle. As the solidity increases, the sound pressure level (SPL) at blade pass frequency increases. Since design of quieter VAWT with application in urban regions recently is of the most interest and importance therefore such deep studies could appropriately address hybrid criteria and be helpful in future investigations.

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Duquette, Matthew M., Jessica Swanson, and Kenneth D. Visser. "Solidity and Blade Number Effects on a Fixed Pitch, 50 W Horizontal Axis Wind Turbine." Wind Engineering 27, no. 4 (August 2003): 299–316. http://dx.doi.org/10.1260/030952403322665271.

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Experimental studies were conducted on a modified Rutland 500 horizontal axis wind turbine to evaluate numerical implications of solidity and blade number on the aerodynamic performance. Wind tunnel data were acquired on the turbine with flat-plate, constant-chord blade sets and optimum-designed blade sets to compare with theoretical trends, which had indicated that increased solidity and blade number more than conventional 3-bladed designs, would yield larger power coefficients, CP. The data for the flat plate blades demonstrated power coefficient improvements as the range of solidities was increased from 7% to 27%, but did not indicate performance gains for increased blade numbers. It was also observed that larger pitch angles decreased the optimum tip speed ratio range significantly with a small (5% or less) change in maximum CP. The optimum-design 3-bladed rotors produced an increased experimental CP as solidity increased, with reduced tip speed ratio, at the optimum operating point. As blade number was increased at a constant solidity of 10% from 3 to 12 blades, aerodynamic efficiency and power sharply decreased, contrary to the numerical predictions and the flat plate experimental results. Low Reynolds numbers and wind tunnel blockage effects limit these conclusions and a full scale prototype rotor is being constructed to examine the results of the numerical and experimental studies using a side-by-side comparison with a commercially available wind turbine at the Clarkson University wind-turbine test site.

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Xiang, Xin, Guoping Huang, Jie Chen, Lei Li, and Weiyu Lu. "Numerical Investigations of a Tip Turbine Aerodynamic Design in a Propulsion System for VTOL Vehicles." Energies 12, no. 15 (August 3, 2019): 3003. http://dx.doi.org/10.3390/en12153003.

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High thrust and low specific fuel consumption (SFC) are important for vertical takeoff and landing (VTOL) vehicles. An effective way to decrease the SFC is to increase the bypass ratio (BPR) of the propulsion system. The air-driven fan (or fan-in-wing) has a very high bypass ratio and has proved to be successful in VTOL aircrafts. However, the tip turbine that extracts energy for the air-driven fan faces the low-solidity problem and performs inadequately. In this study, we developed a high-reaction method for the aerodynamic design of a tip turbine to solve the low-solidity problem. A typical tip turbine was selected and designed by both conventional and high-reaction methods. Three-dimensional flow fields were numerically simulated through a Reynolds-averaged Navier-Stokes (RANS)-based computational fluid dynamics (CFD) method. The energy extraction rate was proposed to evaluate and display the energy extraction capability of the turbine. The results showed that the high-reaction turbine could solve the low-solidity problem and significantly increase the isentropic efficiency from approximately 80.0% to 85.6% and improve the isentropic work by 71.9% compared with the conventional method (from 10.28 kW/kg to 17.67 kW/kg).

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Liem, L. E., Daniel W. Smith, and S. J. Stanley. "Particle reduction study of flocculation mixing by means of grids." Canadian Journal of Civil Engineering 26, no. 3 (June 1, 1999): 251–61. http://dx.doi.org/10.1139/l98-053.

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A flocculation study was completed by means of a vertically oscillating grid mixing device. Five types of single grids with different solidity ratios were vertically oscillated inside a 2 L jar to promote floc aggregation. Kaolin was used as the simulated turbid particles and alum was applied as the chemical coagulant. The method of measurement was completed based on the particle reduction represented by the settled water turbidity. It was found that low turbidity readings could be achieved at a wide range of average volume velocity gradient [Formula: see text], especially in the case of high solidity ratio types of grids. This indicates that the grid mixing had a stable performance and was not greatly affected by mixing variations in the vessel. The floc aggregation and erosion rate coefficient analysis showed that the grid mixing produced particle contacts with low break-up rate. A general relationship among [Formula: see text], flocculation performance parameters, and grid physical characteristics was found, indicating that the flocculation performance was easily controlled. This study has shown the potential of grids as a mixing device to produce an excellent mixing environment for floc aggregation.Key words: flocculation, grid, solidity ratio, kaolin, alum, [Formula: see text], turbidity.

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13

Дорошенко, Екатерина Викторовна, Михаил Владимирович Хижняк, and Юрий Матвеевич Терещенко. "ВПЛИВ ГУСТОТИ РЕШІТКИ НА АЕРОДИНАМІЧНУ НАВАНТАЖЕНІСТЬ РОБОЧОГО КОЛЕСА ОСЬОВОГО ВЕНТИЛЯТОРА." Aerospace technic and technology, no. 4 (August 28, 2020): 38–43. http://dx.doi.org/10.32620/aktt.2020.4.05.

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The main requirements that apply to axial fans and axial compressors of aircraft gas turbine engines include minimum dimensions and weight; high aerodynamic load; high coefficient of performance; wide range of steady work; high reliability. For gas turbine engines, the requirements of minimum weight and dimensions are especially important, since the engines must provide flights at high velocities and altitudes. This study aims to assess the effect of the solidity of the impeller fan on the average radius on the aerodynamic loading of the impeller of an axial fan for an engine with a high bypass ratio. The object of the study is the impeller of the fan. The solidity of the impeller fan on the average radius varied in the range from 1.8 to 0.82, the number of blades of the impeller fan varied from 33 to 15, respectively. The studies in this work were carried out by the method of numerical experiment. The flow in the axial fans was simulated by solving the system of Navier-Stokes equations, which were closed by the SST turbulent viscosity model. Based on the analysis of the results of the study, an assessment is made of the influence of the solidity of the impeller fan at an average radius on the aerodynamic loading of the impeller of an axial fan for an engine with a high bypass ratio. The research results showed that with a decrease in the solidity of the impeller fan at an average radius of 1.8 to 0.82 in operating modes with an axial inlet velocity of 80 to 120 m / s, the impeller fan pressure ratio decreases by 0.11 ... 3.2 %. The maximum decrease in the fan pressure ratio increase for the fan impeller with the parameters studied is 3.2 %, with a decrease in the number of fan blades from 33 to 15, while the total weight of the blades decreases by 54.55 %. The decrease in the solidity on the average radius of the impeller of the studied fan leads to a decrease in the relative sizes of the low-velocity zones at the sleeve and on the periphery and to a decrease in the level of flow unevenness. A further reduction in the level of flow non-uniformity behind the fan is possible when using the boundary layer control in the fan - this is the task of subsequent studies.

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Xu, Wenjuan, Xin Du, Chuansijia Tao, Songtao Wang, and Zhongqi Wang. "Correlation of solidity, aspect ratio and compound lean blade in compressor cascade design." Applied Thermal Engineering 150 (March 2019): 175–92. http://dx.doi.org/10.1016/j.applthermaleng.2018.12.167.

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von Backström, Theodor W. "A Unified Correlation for Slip Factor in Centrifugal Impellers." Journal of Turbomachinery 128, no. 1 (August 10, 2005): 1–10. http://dx.doi.org/10.1115/1.2101853.

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A method that unifies the trusted centrifugal impeller slip factor prediction methods of Busemann, Stodola, Stanitz, Wiesner, Eck, and Csanady in one equation is presented. The simple analytical method derives the slip velocity in terms of a single relative eddy (SRE) centered on the rotor axis instead of the usual multiple (one per blade passage) eddies. It proposes blade solidity (blade length divided by spacing at rotor exit) as the prime variable determining slip. Comparisons with the analytical solution of Busemann and with tried and trusted methods and measured data show that the SRE method is a feasible replacement for the well-known Wiesner prediction method: it is not a mere curve fit, but is based on a fluid dynamic model; it is inherently sensitive to impeller inner-to-outer radius ratio and does not need a separate calculation to find a critical radius ratio; and it contains a constant, F0, that may be adjusted for specifically constructed families of impellers to improve the accuracy of the prediction. Since many of the other factors that contribute to slip are also dependent on solidity, it is recommended that radial turbomachinery investigators and designers investigate the use of solidity to correlate slip factor.

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Difuntorum, John Keithley, and Louis Angelo M. Danao. "Improving VAWT performance through parametric studies of rotor design configurations using computational fluid dynamics." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 233, no. 4 (August 21, 2018): 489–509. http://dx.doi.org/10.1177/0957650918790671.

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Vertical axis wind turbines present several advantages over the horizontal axis machines that make them suitable to a variety of wind conditions. However, due to the complexity of vertical axis wind turbine (VAWT) aerodynamics, available literature on VAWT performance in steady and turbulent wind conditions is limited. This paper aims to numerically predict the performance of a 5 kW VAWT under steady wind conditions through computational fluid dynamics modeling by varying turbine configuration parameters. Two-dimensional VAWT models using a cambered blade (1.5%) were created with open field boundary extents. Turbine configuration parameters studied include blade mounting position, blade fixing angle, and rotor solidity. Baseline case with peak Cp of 0.31 at tip-speed ratio of 4 has the following parameters: mounting position at 0.5c, zero fixing angle, and three blades (solidity = 0.3). Independent parametric studies were carried out and results show that a blade mounting position of 0.7c from the leading edge produces the best performance with maximum Cp = 0.315 while the worst case is a mounting position of 0.15c with peak Cp = 0.273. Fixing angle study reveals a toe-out setting of −1° producing the best performance with peak Cp of 0.315 and the worst setting at toe-in of 1.5° with peak Cp of 0.287. The solidity study resulted in the best case of four blades (solidity = 0.4) with peak Cp = 0.316 and the worst case of two blades (solidity = 0.2) with peak Cp = 0.283.

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Carrigan, Travis J., Brian H. Dennis, Zhen X. Han, and Bo P. Wang. "Aerodynamic Shape Optimization of a Vertical-Axis Wind Turbine Using Differential Evolution." ISRN Renewable Energy 2012 (January 16, 2012): 1–16. http://dx.doi.org/10.5402/2012/528418.

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The purpose of this study is to introduce and demonstrate a fully automated process for optimizing the airfoil cross-section of a vertical-axis wind turbine (VAWT). The objective is to maximize the torque while enforcing typical wind turbine design constraints such as tip speed ratio, solidity, and blade profile. By fixing the tip speed ratio of the wind turbine, there exists an airfoil cross-section and solidity for which the torque can be maximized, requiring the development of an iterative design system. The design system required to maximize torque incorporates rapid geometry generation and automated hybrid mesh generation tools with viscous, unsteady computational fluid dynamics (CFD) simulation software. The flexibility and automation of the modular design and simulation system allows for it to easily be coupled with a parallel differential evolution algorithm used to obtain an optimized blade design that maximizes the efficiency of the wind turbine.

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McFarlane, Caroline M., Xue-Ming Zhao, and Alvin W. Nienow. "Studies of high solidity ratio hydrofoil impellers for aerated bioreactors. 2. Air-water studies." Biotechnology Progress 11, no. 6 (November 1995): 608–18. http://dx.doi.org/10.1021/bp00036a002.

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19

Chen, Yan Jun, Guo Qing Wu, Yang Cao, Dian Gui Huang, Qin Wang, and Shu Qian Wu. "Numerical Research on the Characteristics of Lift-Drag Type Vertical Axis Wind Turbine." Applied Mechanics and Materials 189 (July 2012): 448–52. http://dx.doi.org/10.4028/www.scientific.net/amm.189.448.

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Numerical studies are conducted to research the performance of a kind of lift-drag type vertical axis wind turbine (VAWT) affected by solidity with the CFD method. Moving mesh technique is used to construct the model. The Spalart-Allmaras one equation turbulent model and the implicit coupled algorithm based on pressure are selected to solve the transient equations. In this research, how the tip speed ratio and the solidity of blade affect the power coefficient (Cp) of the small H-VAWT is analyzed. The results indicate that Cp curves exhibit approximate parabolic form with its maximum in the middle range of tip speed ratio. The two-blade wind turbine has the lowest Cp while the three-blade one is more powerful and the four-blade one brings the highest power. With the certain number of blades, there is a best chord length, and too long or too short chord length may reduce the Cp.

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Hayami, H., Y. Senoo, and K. Utsunomiya. "Application of a Low-Solidity Cascade Diffuser to Transonic Centrifugal Compressor." Journal of Turbomachinery 112, no. 1 (January 1, 1990): 25–29. http://dx.doi.org/10.1115/1.2927416.

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Low-solidity circular cascades, conformally transformed from high-stagger linear cascades of double-circular-arc vanes with solidity 0.69, were used as a part of the diffuser system of a transonic centrifugal compressor. Performance test results were compared with data of the same compressor with a vaneless diffuser. Good compressor performance and a wider flow range as well as a higher pressure ratio and a higher efficiency, superior to those with a vaneless diffuser, where the flow range was limited by choke of the impeller, were demonstrated. The test circular cascade diffusers demonstrated a good pressure recovery over a wide range of flow angles, even when the inflow Mach number to the cascade was over unity.

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Wang, Hejian, Yanshan Qing, Bo Liu, and Xiaochen Mao. "Corner Separation Control Using a New Combined Slotted Configuration in a High-Turning Compressor Cascade under Different Solidities." Energies 14, no. 12 (June 8, 2021): 3376. http://dx.doi.org/10.3390/en14123376.

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In order to comprehensively control the corner separation and the blade trailing edge (TE) separation in a high-turning compressor stator cascade, this research proposes a new combined slotted configuration consisting of one full-span slot and two blade-end slots. Taking into account the effect of the blade solidity, the performance of the original cascade and the combined slotted cascade was calculated and evaluated in a wide incidence angle range at two blade solidities. The results indicated that the blade loading and the corner separation range of the original cascade becomes larger as the blade solidity decreases from 1.66 to 1.36, which leads to higher total pressure loss and lower pressure diffusing capacity under positive incidence angles. The low-momentum fluid in the boundary layer can be significantly re-energized by the high-momentum blade-end and full-span slots jets, hence the combined slotted configuration can eliminate the blade TE separation and reduce the corner separation remarkably in the full incidence angle range at the two blade solidities. By adopting the combined slotted configuration, the total pressure loss, turning angle and static pressure coefficient of the original cascade can be increased by −23.2%, 2.7° and 4.7% on average, respectively, when the blade solidity is 1.66, while they can be increased by −27.7%, 3.3° and 7.6% on average, respectively, when the blade solidity is 1.36. The combined slotted configuration has a significant adaptability to the low blade solidity (or high loading) condition and it shows a certain potential in increasing the aeroengine thrust-to-weight ratio by decreasing the compressor single-stage blade number.

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Gato, L. M. C., and R. Curran. "Performance of the Biplane Wells Turbine." Journal of Offshore Mechanics and Arctic Engineering 118, no. 3 (August 1, 1996): 210–15. http://dx.doi.org/10.1115/1.2828836.

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The paper describes the experimental investigation of the biplane Wells turbine for use on a wave power plant. The performance of the biplane turbine was tested in unidirectional steady air flow by varying the model configurations using solidity, gap-to-chord ratio, and rotor stagger angle. It was found that the gap-to-chord ratio and stagger considerably influenced the performance of the biplane turbine due to the mutual interference between the rotor planes.

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Cui, Cui, Zhenggui Zhou, Jinhuan Zhang, and Sheng Tao. "Influence of key geometric parameters on the aerodynamic performance of a supersonic compressor cascade." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 232, no. 12 (June 14, 2017): 2338–48. http://dx.doi.org/10.1177/0954410017713772.

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The shocks in a supersonic/transonic axial compressor can increase the pressure ratio and cause flow losses. Therefore, it is essential to organize the shock wave pattern in the flow passage to reduce these losses. This study uses a numerical simulation method to study the influences of the leading-edge radius, cascade solidity, and pre-compression on the aerodynamic performance of a supersonic cascade. The cascade is designed using the pre-compression method to reduce shock losses; the inlet Mach number is 2.0 and the total pressure ratio is approximately 3.4. The results indicate that the cascade efficiency and stall margin decrease with an increase in the leading-edge radius; however, when the leading-edge radius is less than 0.1 mm, the influences of its change decrease. As cascade solidity increases, the stall margin first increases and then decreases. The larger the degree of pre-compression, the smaller the Mach number in front of the first oblique passage shock and the higher the efficiency; however, a large pre-compression effect can cause the ending normal shock to move upstream, decreasing the stall margin.

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Eynon, P. A., and A. Whitfield. "The effect of low-solidity vaned diffusers on the performance of a turbocharger compressor." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 211, no. 5 (May 1, 1997): 325–39. http://dx.doi.org/10.1243/0954406971522088.

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The design of low-solidity diffuser vanes and the effect on the performance of a turbo-charger compressor is discussed. The effect of vane number and turning angle was investigated while maintaining a basic design with a solidity of 0.69 and a leading edge angle of 75°. This large leading edge angle was specifically chosen so that the vane would be aligned with the low flowrates close to surge. Tests were initially conducted with six, eight and ten vanes and a turning angle of 10°. Based on these results the ten-vane design was selected for further investigation with 15 and 20° of vane turning; this led to vane exit angles of 60 and 55° respectively. All results are compared with those obtained with the standard vaneless diffuser configuration and it was shown that all designs increased and shifted the peak pressure ratio to reduced flowrates. The peak efficiency was reduced relative to that obtained with the vaneless diffuser. Despite the low-solidity configuration none of the vane designs provided a broad operating range without the use of a variable geometry configuration. This was attributed to the selection of a large leading edge vane angle.

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McFarlane, C. M., and A. W. Nienow. "Studies of High Solidity Ratio Hydrofoil Impellers for Aerated Bioreactors. 4. Comparison of Impeller Types." Biotechnology Progress 12, no. 1 (February 5, 1996): 9–15. http://dx.doi.org/10.1021/bp950034o.

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Simmons, M. J. H., H. Zhu, W. Bujalski, C. J. Hewitt, and A. W. Nienow. "Mixing in a Model Bioreactor Using Agitators with a High Solidity Ratio and Deep Blades." Chemical Engineering Research and Design 85, no. 5 (January 2007): 551–59. http://dx.doi.org/10.1205/cherd06157.

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Zhang, Li Chong, Wen Yong Xu, Zhou Li, Liang Zheng, Yu Feng Liu, and Guo Qing Zhang. "Effect of Particle Size and Shape on Flowability of FGH96 Superalloy Powder." Materials Science Forum 1035 (June 22, 2021): 143–51. http://dx.doi.org/10.4028/www.scientific.net/msf.1035.143.

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The effect of particle size and shape on flowability of FGH96 superalloy powder was investigated by field emission scanning electron microscopy (FE-SEM), laser particle size analyzer (LPSA) and X-ray photoelectron spectroscopy (XPS). The results showed that the powder flowability basically presented a decreasing trend as the median diameter decreased. The Hall velocity of the five median diameter powders (50=203.9 μm, 106.3 μm, 83.2 μm, 73.8 μm, 19.9 μm) was 27.18 s/50g, 23.25 s/50g, 23.86 s/50g, 23.42 s/50g and none, respectively. The surface oxides/ hydroxide/nitride of the five median diameter powders were mostly the same, mainly including Al2O3, Cr2O3, MoO3, Nb2O5, Ni (OH)2, TiO2 and TiN. The median diameter 50, shape factors (circularity, aspect ratio, roundness, solidity) and fractal dimension were selected to quantitatively characterize particle size and shape. For the same fluctuation value of powder flowability, the roundness and solidity showed lower sensitivity. Compared with the two shape factors, the sensitivity of circularity and aspect ratio was at an intermediate level, while the median diameter and fractal dimension displayed higher sensitivity. The median diameter and fractal dimension can be used to characterize the principal variation of flowability. The circularity and aspect ratio can be utilized to characterize the variation of flowability supplementally.

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Joshi, Shubhash, and Ajay Kumar Jha. "Computational and Experimental Study of the Effect of Solidity and Aspect Ratio of a Helical Turbine for Energy Generation in a Model Gravitational Water Vortex Power Plant." Journal of Advanced College of Engineering and Management 6 (July 10, 2021): 213–19. http://dx.doi.org/10.3126/jacem.v6i0.38360.

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Gravitational Water Vortex power plant is a relatively new plant used to generate hydropower from low head rivers and canals. There has been an increase in research in the field of runner design and canal design for GWVPPs throughout the world. As no definite equations are formulated in case of runners used in a GWVPP, they are currently produced by hit and trial method. This research focuses on studying about the use of a pure reaction turbine, Gorlov turbine, to generate power from a GWVPP. ANSYS Fluent was used to perform computational study while the experimental study was done using helical turbine blades fabricated using a 3-D printer. The energy generated is very low compared to the impulse turbines. Both the computational and experimental study shows that when increasing the aspect ratio of the turbine but keeping the solidity same, the efficiency is increased significantly. However, the studies also show that on increasing the solidity, the efficiency seems to decrease. All the turbines used submerged to 3 different depts and all the results show that increasing the submergence increased the efficiency.

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Moreau, Stéphane, and Michel Roger. "Advanced noise modeling for future propulsion systems." International Journal of Aeroacoustics 17, no. 6-8 (July 28, 2018): 576–99. http://dx.doi.org/10.1177/1475472x18789005.

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In order to meet noise specifications for future foreseen aircraft propulsion systems, such as for ultrahigh bypass ratio turbofans and contra-rotating open rotors, the dominant turbomachinery noise mechanisms need to be modeled accurately at an early design stage. Two novel methods are presented here, which could significantly improve the existing analytical noise models. For the high-solidity ultrahigh bypass ratio, a mode-matching technique based on a modal expansion of acoustic and vortical variables in each subdomain of a blade row is shown to accurately reproduce sound generation and propagation in two-dimensional bifurcated channels and in three-dimensional annular unstaggered flat-plate cascades. For the low solidity contra-rotating open rotors, several extensions to Amiet’s compressible isolated airfoil theory are coupled with Curle’s and Ffowcs Williams and Hawkings’ acoustic analogy in the frequency domain within a strip theory framework, to yield both far-field tonal and broadband noise. Including sweep in both tonal and broadband noise models is shown to significantly improve the comparison with experiments on a stationary swept airfoil in a uniform turbulent stream and on a realistic contra-rotating open rotor geometry at approach conditions.

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Encarnacion, Job Immanuel, Cameron Johnstone, and Stephanie Ordonez-Sanchez. "Design of a Horizontal Axis Tidal Turbine for Less Energetic Current Velocity Profiles." Journal of Marine Science and Engineering 7, no. 7 (June 27, 2019): 197. http://dx.doi.org/10.3390/jmse7070197.

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Existing installations of tidal-stream turbines are undertaken in energetic sites with flow speeds greater than 2 m/s. Sites with lower velocities will produce far less power and may not be as economically viable when using “conventional” tidal turbine designs. However, designing turbines for these less energetic conditions may improve the global viability of tidal technology. Lower hydrodynamic loads are expected, allowing for cost reduction through downsizing and using cheaper materials. This work presents a design methodology for low-solidity high tip-speed ratio turbines aimed to operate at less energetic flows with velocities less than 1.5 m/s. Turbines operating under representative real-site conditions in Mexico and the Philippines are evaluated using a quasi-unsteady blade element momentum method. Blade geometry alterations are undertaken using a scaling factor applied to chord and twist distributions. A parametric filtering and multi-objective decision model is used to select the optimum design among the generated blade variations. It was found that the low-solidity high tip-speed ratio blades lead to a slight power drop of less than 8.5% when compared to the “conventional” blade geometries. Nonetheless, an increase in rotational speed, reaching a tip-speed ratio (TSR) of 7.75, combined with huge reduction in the torque requirement of as much as 30% paves the way for reduced costs from generator downsizing and simplified power take-off mechanisms.

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31

Zdilla, Matthew J., Scott A. Hatfield, Kennedy A. McLean, Leah M. Cyrus, Jillian M. Laslo, and H. Wayne Lambert. "Circularity, Solidity, Axes of a Best Fit Ellipse, Aspect Ratio, and Roundness of the Foramen Ovale." Journal of Craniofacial Surgery 27, no. 1 (January 2016): 222–28. http://dx.doi.org/10.1097/scs.0000000000002285.

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32

Gori, Fabio, and Ivano Petracci. "Influence of screen solidity ratio on heat transfer upon a cylinder impinged by a rectangular jet." International Journal of Heat and Mass Transfer 81 (February 2015): 19–27. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2014.10.004.

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33

Song, Bo, Wing F. Ng, Joseph A. Cotroneo, Douglas C. Hofer, and Gunnar Siden. "Aerodynamic Design and Testing of Three Low Solidity Steam Turbine Nozzle Cascades." Journal of Turbomachinery 129, no. 1 (March 1, 2004): 62–71. http://dx.doi.org/10.1115/1.2372774.

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Three sets of low solidity steam turbine nozzle cascades were designed and tested. The objective was to reduce cost through a reduction in parts count while maintaining or improving performance. The primary application is for steam turbine high pressure sections where Mach numbers are subsonic and high levels of unguided turning can be tolerated. The base line design A has a ratio of pitch to axial chord of 1.2. This is the pitch diameter section of a 50% reaction stage that has been verified by multistage testing on steam to have a high level of efficiency. Designs B and C have ratios of pitch to axial chord of 1.5 and 1.8, respectively. All three designs satisfy the same inlet and exit vector diagrams. Analytical surface Mach number distributions and boundary layer transition predictions are presented. Extensive cascade test measurements were carried out for a broad incidence range from −60to+35deg. At each incidence, four outlet Mach numbers were tested, ranging from 0.2 to 0.8, with the corresponding Reynolds number variation from 1.8×105 to 9.0×105. Experimental results of loss coefficient and blade surface Mach number are presented and compared for the three cascades. The experimental results have demonstrated low losses over the tested Mach number range for a wide range of incidence from −45to15deg. Designs B and C have lower profile losses than design A. The associated flow physics is interpreted using the results of wake profile, blade surface Mach number distribution, and blade surface oil flow visualization, with the emphasis placed on the loss mechanisms for different flow conditions and the loss reduction mechanism with lower solidity. The effect of the higher profile loading of the lower solidity designs on increased end wall losses induced by increased secondary flow, especially on low aspect ratio designs, is the subject of ongoing studies.

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Piovesan, Tommaso, Andrea Magrini, and Ernesto Benini. "Accurate 2-D Modelling of Transonic Compressor Cascade Aerodynamics." Aerospace 6, no. 5 (May 19, 2019): 57. http://dx.doi.org/10.3390/aerospace6050057.

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Modern aeronautic fans are characterised by a transonic flow regime near the blade tip. Transonic cascades enable higher pressure ratios by a complex system of shockwaves arising across the blade passage, which has to be correctly reproduced in order to predict the performance and the operative range. In this paper, we present an accurate two-dimensional numerical modelling of the ARL-SL19 transonic compressor cascade. A large series of data from experimental tests in supersonic wind tunnel facilities has been used to validate a computational fluid dynamic model, in which the choice of turbulence closure resulted critical for an accurate reproduction of shockwave-boundary layer interaction. The model has been subsequently employed to carry out a parametric study in order to assess the influence of main flow variables (inlet Mach number, static pressure ratio) and geometric parameters (solidity) on the shockwave pattern and exit status. The main objectives of the present work are to perform a parametric study for investigating the effects of the abovementioned variables on the cascade performance, in terms of total-pressure loss coefficient, and on the shockwave pattern and to provide a quite large series of data useful for a preliminary design of a transonic compressor rotor section. After deriving the relation between inlet and exit quantities, peculiar to transonic compressors, exit Mach number, mean exit flow angle and total-pressure loss coefficient have been examined for a variety of boundary conditions and parametrically linked to inlet variables. Flow visualisation has been used to describe the shock-wave pattern as a function of the static pressure ratio. Finally, the influence of cascade solidity has been examined, showing a potential reduction of total-pressure loss coefficient by employing a higher solidity, due to a significant modification of shockwave system across the cascade.

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Chen, T. Y., C. W. Hung, and Y. T. Liao. "Experimental Study on Aerodynamics of Micro-Wind Turbines with Large-Tip non-Twisted Blades." Journal of Mechanics 29, no. 3 (May 14, 2013): N15—N20. http://dx.doi.org/10.1017/jmech.2013.35.

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AbstractThis research experimentally investigates the rotor aerodynamics of horizontal-axis, micro-wind turbines. Specifically, the aerodynamic characteristics of large-tip, non-twisted blades are studied. The study is conducted in a wind tunnel system to obtain the relations between the power coefficient (CP) and tip speed ratio (TSR), the torque coefficient (CT) and TSR. Effects of rotor position inside a flanged diffuser, rotor solidity and blade number on rotor performance are investigated. The blade cross-section is NACA4415 airfoil. The pitch angle of the blades is fixed at 30°, and the chord length ratio between the blade root and tip (Cr / Ct) is fixed at 0.3. Results show that larger power output is obtained when the rotor placed closer to the diffuser inlet. The 60%-solidity rotor, in general, achieves better power and torque outputs among the test rotor solidities. The higher the blade number is, the larger the power output is, but the difference is small. Comparisons between the present and previous relatively short-tip blades (Cr / Ct = 0.5) show that the present blades have better power and torque outputs at lower rotor rotational speed. These results suggest that the large-tip blades are suitable for micro-wind turbine applications, and make rotor-generator matching more flexible.

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Guangnian, Li, Qingren Chen, Yue Liu, Shanqiang Zhu, and Qun Yu. "Study on Hydrodynamic Configuration Parameters of Vertical-Axis Tidal Turbine." Polish Maritime Research 27, no. 1 (March 1, 2020): 116–25. http://dx.doi.org/10.2478/pomr-2020-0012.

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AbstractIn this paper, a numerical code for predicting the hydrodynamic performance of vertical-axis tidal turbine array is developed. The effect of the tip speed ratio, solidity, and preset angle on the hydrodynamic performance are discussed using a series of calculations. The load principle of the rotor and the variation principle of the turbine power coefficient are studied. All these results can be considered as a reference for the design of vertical-axis tidal turbines.

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Tang, Yumeng, Yangwei Liu, and Lipeng Lu. "Solidity effect on corner separation and its control in a high-speed low aspect ratio compressor cascade." International Journal of Mechanical Sciences 142-143 (July 2018): 304–21. http://dx.doi.org/10.1016/j.ijmecsci.2018.04.048.

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38

Tang, Hao, Fuxiang Hu, Liuxiong Xu, Shuchuang Dong, Cheng Zhou, and Xuefang Wang. "The effect of netting solidity ratio and inclined angle on the hydrodynamic characteristics of knotless polyethylene netting." Journal of Ocean University of China 16, no. 5 (August 12, 2017): 814–22. http://dx.doi.org/10.1007/s11802-017-3227-6.

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39

Niño, Yarko, Kevin Vidal, Aldo Tamburrino, Luis Zamorano, Juan Felipe Beltrán, Gustavo Estay, and Aldo Muñoz. "Normal and Tangential Drag Forces of Nylon Nets, Clean and with Fouling, in Fish Farming. An Experimental Study." Water 12, no. 8 (August 9, 2020): 2238. http://dx.doi.org/10.3390/w12082238.

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Experiments in a laboratory tank have provided measurements of the normal and tangential drag forces exerted on flat nets for different flow conditions. From those forces, normal and tangential drag coefficients of the nets have been obtained as functions of the Reynolds number and the solidity index. The experiments used two types of nets employed in the operation of a cultivation center: the fish net and the sea lion net, for the clean situation and for real operating conditions, with fouling adhered to the nets. Polyethylene ropes were used to characterize the presence of fouling in the nets. The experiments were carried out to determine equations for the normal and tangential drag coefficients. For the normal drag coefficient, the equations are linear with the Reynolds number, and the coefficients of the equations are linear with the solidity index. The equations are not so accurate for the tangential drag coefficient. The Reynolds number is not a relevant parameter for this coefficient and neither is the solidity index for the fish net, but the coefficient grows slightly with it for single and double sea lion nets with fouling. The literature review on the drag forces of nets reports that the tangential drag force is around 30% of the normal drag force. This value is approximately an average value of the ratio for the sea lion net and is higher for the clean fish net in this article.

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40

Mon, Thuzar, and Supakit Worasinchai. "Performance modelling of the Darrieus wind turbine." E3S Web of Conferences 302 (2021): 01001. http://dx.doi.org/10.1051/e3sconf/202130201001.

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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.

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41

Wang, Xiao Bo, and Chuan Sheng Wang. "A Method of Treating Impurities in the Process of Detecting Carton Black in Rubber." Advanced Materials Research 781-784 (September 2013): 483–86. http://dx.doi.org/10.4028/www.scientific.net/amr.781-784.483.

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Distinguishing carton black and impurity is important for evaluating carton black’s dispersion in rubber. There are two types of impurities, filamentous impurity and scratch. According to the characteristics of filamentous impurity, the ratio of perimeter to solidity of region and hole’s area were calculated to distinguish this type of impurity. If hole’s area was larger than 3 or the value of the ratio larger than 160, the region was regarded as filamentous impurity. Scratch was very like line, which could be identified by the way of hough translation. The treatment of impurities based on morphology is helpful for improving the accuracy of detecting carton black and calculating carton black’s dispersion.

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42

Ramlee, Muhamad Fadhli, Ahmad Fazlizan, and Sohif Mat. "Performance Evaluation of H-Type Darrieus Vertical Axis Wind Turbine with Different Turbine Solidity." Journal of Computational and Theoretical Nanoscience 17, no. 2 (February 1, 2020): 833–39. http://dx.doi.org/10.1166/jctn.2020.8726.

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Among renewable energy resources, wind energy is one of the best alternative for power generation. Recently, vertical axis wind turbine (VAWT) received renewed interest as small-scale wind energy converter due to its suitability for urban application, where the wind condition is known to be unsteady and turbulence. Amongst various type of VAWTs, H-type Darrieus rotor has become more popular, thanks to its simple construction features, resulting to low manufacturing and installation cost. The aim of this paper is to evaluate numerically the power performance of straight-bladed Darrieus VAWT with different turbine solidity using computational fluid dynamic (CFD) technology. A series of two-dimensional CFD simulations of a three-bladed H-type Darrieus rotor were performed with 3 different solidities, σ (0.3, 0.5 and 0.7) to evaluate their power performance. Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations were used to calculate the instantaneous moment coefficient, Cm and power coefficient, Cp over a range of tip speed ratio, λ (0.5–4.5) with a free stream velocity of 8.0 m/s. The simulation results show that high solidity turbine performed well at low values of λ while turbine with low solidity has a wider operating range of λ and performed better at λ > 3.0 due to less blade-wake interactions between upstream and downstream halves of the turbine and lower blockage effect. The findings lend substantially to our understanding of physics flow around blades and turbine in order to optimize the power performance of small scale straight-bladed Darrieus VAWT operating in unsteady and turbulence wind condition.

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43

Sanger, N. L., and R. P. Shreeve. "Comparison of Calculated and Experimental Cascade Performance for Controlled-Diffusion Compressor Stator Blading." Journal of Turbomachinery 108, no. 1 (July 1, 1986): 42–50. http://dx.doi.org/10.1115/1.3262023.

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The midspan section of a previously reported controlled-diffusion compressor stator has been experimentally evaluated in cascade. Measurements were taken over a range of incidence angles for blade chord Reynolds numbers from 470,000 to 690,000. Blade chord length was 12.7 cm, aspect ratio was 2.0, and solidity was 1.67. Measurements included conventional cascade performance parameters as well as blade surface pressures. Computations were made for the inviscid flow field, surface boundary layers, and loss for several of the blade inlet angle conditions, and compared against corresponding data.

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44

KANEKO, Kenji, Toshiaki SETOGUCHI, Shigemi HAYASHI, and Masahiro INOUE. "Studies on a diagonal-flow airfoil fan with low loading. 1st report Effects of aspect ratio and solidity." Transactions of the Japan Society of Mechanical Engineers Series B 52, no. 473 (1986): 379–85. http://dx.doi.org/10.1299/kikaib.52.379.

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45

Jegatheeswaran, Sinthuran, Argang Kazemzadeh, and Farhad Ein-Mozaffari. "Enhanced aeration efficiency in non-Newtonian fluids using coaxial mixers: High-solidity ratio central impeller with an anchor." Chemical Engineering Journal 378 (December 2019): 122081. http://dx.doi.org/10.1016/j.cej.2019.122081.

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KANEKO, Kenji, Toshiaki SETOGUCHI, Shigemi HAYASHI, and Masahiro INOUE. "Studies on a Diagonal-Flow Airfoil Fan with Low Loading : 1st Report, Effects of Aspect Ratio and Solidity." Bulletin of JSME 29, no. 255 (1986): 2932–37. http://dx.doi.org/10.1299/jsme1958.29.2932.

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47

Peters, Markus, Tobias Schmidt, and Peter Jeschke. "Influence of Blade Aspect Ratio on Axial Compressor Efficiency." Journal of the Global Power and Propulsion Society 3 (October 23, 2019): 639–52. http://dx.doi.org/10.33737/jgpps/111735.

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A numerical study on the influence of compressor blade aspect ratio on profile and secondary loss has been conducted. In order to more accurately estimate the change in secondary loss, a new analytical model has been developed. The aspect ratio has been increased by reducing blade chord while maintaining blade height and solidity. A simplified compressor cascade geometry and an engine-like HPC stage geometry (rotor blade and stator vane) have been analysed with 3D CFD simulations. For these simulations, the solver TRACE has been used together with the k-ω turbulence model and a Low-Reynolds approach. A negative effect of increased aspect ratio on profile loss due to the lower Reynolds number has been observed as expected from literature. Moreover a decrease of secondary loss at increased aspect ratio due to smaller endwall regions has been noticed. While this effect is also well known, a significant influence of the assumptions regarding the incoming boundary layer thickness has been observed based on the cascade simulations. This leads to the conclusion that changing the aspect ratio of all blades and vanes of a multistage compressor causes a much stronger decrease in secondary loss per blade row than changing the aspect ratio of a single rotor or stator within the compressor. In literature so far only the first case is considered in common loss correlations. However considering the latter would increase the accuracy of secondary loss estimation for a non-uniform change in aspect ratio within a compressor.

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48

Jones, Norman. "Some comments on the energy-absorbing effectiveness factor." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 232, no. 8 (October 16, 2017): 1433–45. http://dx.doi.org/10.1177/0954406217723365.

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This paper discusses the energy-absorbing effectiveness factor which provides a ratio between the energy absorbed in a structural system with the total potentially available elastic and plastic strain energies in all the materials used in the construction. Experimental and numerical predictions for the factor are expressed in terms of the solidity ratio, or relative density, for various tubes and multicellular sections subjected to static and impact axial loadings. The factor illustrates the effectiveness of multicellular systems when compared to simple regular geometries. The effect of infilling is discussed along with several other factors. The energy-absorbing effectiveness factor is a useful dimensionless quantity to assist in the choice of efficient designs of structural systems which require an energy-absorbing capability.

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McFarlane, C. M., and A. W. Nienow. "Studies of High Solidity Ratio Hydrofoil Impellers for Aerated Bioreactors. 3. Fluids of Enhanced Viscosity and Exhibiting Coalescence Repression." Biotechnology Progress 12, no. 1 (February 5, 1996): 1–8. http://dx.doi.org/10.1021/bp950033w.

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Liu, Yan, Peng Fei Zhao, Xiao Hui Su, and Guang Zhao. "Numerical Study of Performances of Vertical Axis Tidal Turbines." Advanced Materials Research 455-456 (January 2012): 296–301. http://dx.doi.org/10.4028/www.scientific.net/amr.455-456.296.

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Numerical simulations of flows over two-dimensional vertical axis tidal turbines are carried out. Unsteady Reynolds averaged Navier-Stokes Equations are applied to model turbulent flows. Influence of the central shaft and number of blades on flow field and thus performances of turbines are investigated. Performances in terms of torque and power coefficients are obtained for different types of turbines. Results demonstrates that the central shaft has a negative influence on flow field and power coefficients. Solidity and tip speed ratio are two important factors to affect turbine’s performances. This paper provides useful information for future studies.

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Journal articles on the topic 'Solidity ratio'

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