Journal of Hydrodynamics, Journal Year: 2023, Volume and Issue: 35(5), P. 993 - 1007
Published: Oct. 1, 2023
Language: Английский
Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(2)
Published: Feb. 1, 2025
The widespread adoption of intermittent wind and solar energy sources disrupts the stability power grids, necessitating frequent load rejection processes for pump-turbine. This jeopardizes pump-turbine units. To investigate operating behavior units during rejection, this study focuses on a Francis reversible Employing results from one-dimensional characteristic line method as boundary conditions, three-dimensional numerical simulations are conducted. entropy production theory was employed to quantify loss in different components, including direct dissipation, turbulent wall shear stress. And pressure curves runner blades at spans extracted. flow characteristics, losses, loads within passage analyzed various moments process. Results demonstrate that when unit undergoes it repeatedly transitions into out S-characteristic region. state is most unfavorable under reverse pump with reaching its maximum value 339 160 W/K. When unit's rotational speed increased beyond 1.1nd, water thrust torque underwent drastic changes. Moreover, significant variations runaway difference among up 33 000 kPa. These findings provide scientific basis ensuring safe reliable operation processes.
Language: Английский
Citations
2
Applied Energy, Journal Year: 2024, Volume and Issue: 364, P. 123117 - 123117
Published: April 8, 2024
Language: Английский
Citations
9
Renewable Energy, Journal Year: 2024, Volume and Issue: 225, P. 120271 - 120271
Published: March 6, 2024
Language: Английский
Citations
8
Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(8)
Published: Aug. 1, 2024
Vertical axis wind turbines (VAWTs) have garnered significant attention due to their omnidirectionality, low noise, suitability for turbulent conditions, and high efficiency in offshore cluster deployments. VAWTs are more sensitive dynamic stall, which can lead reduced performance reliability. Selecting appropriate blade airfoils enhance both This study employs a parametric method design 12 input parameters controlling the airfoil, with average power coefficient of single vertical turbine variation main shaft as output parameters. The Non-dominated Sorting Genetic Algorithm II multi-objective genetic algorithm is used airfoil optimization, selecting two best-performing from Pareto front. increased by 8.6% 4.3%, respectively, while decreased up 6.7% 5.3%. analysis blades at different azimuth angles indicates that optimized suppress flow separation attack, enable faster wake recovery, reduce energy loss.
Language: Английский
Citations
5
Heliyon, Journal Year: 2025, Volume and Issue: 11(1), P. e41511 - e41511
Published: Jan. 1, 2025
Single-channel pump is a type of centrifugal that frequently utilized for wastewater treatment around the world, but they often operate at low flow rates with efficiency and loud noise because contains many impurities. In this study, an adjustable tongue vane was developed controls internal direction in volute to increase energy performance single-channel pump. Numerical simulations were conducted by using Reynolds-averaged Navier-Stokes equations shear stress transport turbulence model evaluate loss inside volute. experiment, demonstrated stable operation waste environment. numerical simulation, -10° increased total head 1.007 % 1.242 %, respectively compared reference best point. At rates, however, -20° up 25.126 5.604 respectively, while decreasing power consumption 15.533 model. This improvement attributed suppressing separation flow, which reduces hydraulic losses dissipation. The proposed can be used improve not only pumps also other turbomachinery.
Language: Английский
Citations
0
Journal of Marine Science and Application, Journal Year: 2025, Volume and Issue: unknown
Published: May 3, 2025
Language: Английский
Citations
0
Engineering Applications of Computational Fluid Mechanics, Journal Year: 2024, Volume and Issue: 18(1)
Published: Feb. 2, 2024
The diagonal flow fan, known for its innovative airflow guiding technique, presents a dual advantage of heightened efficiency and reduced noise levels. Despite garnering attention in energy production systems, research on optimizing outlet guide vanes fan performance remains limited. This study introduces novel machine learning approach, utilizing Opt LHD sampling instead traditional simulations experiments to accumulate ample sample data. fusion LS-SVM improved GA-PSO is employed multi-objective optimization vanes, aiming simultaneously enhance reduce consumption. Experimental assessments reveal the optimized fan's significant improvements, including 106 Pa increase total pressure, 3.6 dB reduction levels, remarkable 16.3% enhancement pressure efficiency. These results highlight robustness approach exit effectively addressing gap this area. Additionally, numerical analysis internal dynamics acoustic properties pre post-optimization uncovers intrinsic mechanisms influencing overall fan.
Language: Английский
Citations
3
Journal of Marine Science and Engineering, Journal Year: 2024, Volume and Issue: 12(8), P. 1277 - 1277
Published: July 29, 2024
This study investigates cloud cavitation suppression around a model-scale NACA66 hydrofoil using active water injection and explores the effect of multiple parameters. Numerical simulations mixed-level orthogonal test method are employed to systematically analyze impact jet angle αjet, location Ljet, velocity Ujet on efficiency energy performance. The reveals that has greatest influence suppression, while optimal parameter combination (Ljet = 0.30C, αjet +60 degrees, 3.25 m/s) effectively balances performance reducing volume by 49.34% improving lift–drag ratio 8.55%. found jet’s introduction not only enhances vapor condensation reduces intensity vapor–liquid exchange process but also disrupts internal structure clouds elevates pressure suction surface, thereby suppressing cavitation. Further analysis shows positive-going horizontal components enhance ratio, negative-going have detrimental effect. Jet arrangements near trailing edge negatively both These findings provide valuable reference for selecting parameters achieve balance between in hydrodynamic systems.
Language: Английский
Citations
3
Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)
Published: Feb. 22, 2025
As the global demand for energy conservation increases, achieving efficient conversion in fans has become a significant challenge field of mine ventilation. To investigate influence blade installation angle distribution spanwise direction on characteristics mining counter-rotating axial flow fan, three optimization schemes were proposed this paper. The internal fan was obtained by numerical simulation and experimental methods. Based entropy production theory, correlation between loss parameters established, thus quantitative assessment loss. research findings indicate differences before after optimization, with scheme OP1 (when case 1 is applied to both front impeller rear impeller) demonstrating superior performance. Compared original efficiency total pressure increase 1.1% 1.3%, respectively, under 1.0 QBEP condition (QBEP rate at best point). Furthermore, 1.2 condition, improvements reach 3.1% 4.7%, respectively. improvement mainly attributed reduction induced turbulent dissipation within downstream domain. Notably, distinct rates extension pipe different schemes, reduced 24.6% compared that condition.
Language: Английский
Citations
0
AIP Advances, Journal Year: 2024, Volume and Issue: 14(3)
Published: March 1, 2024
As the core equipment of pumped storage power stations, reversible pump-turbines will frequently switch between different working modes during operation, and it is easy to appear hump region under pump condition, which greatly affect performance unit. Therefore, in order explore causes region, this paper takes model pump-turbine as research object. First, unit speed–unit flow characteristics are compared with test results conditions. Then, based on omega vortex identification method, distribution channel analyzed. By analyzing components rates internal law revealed. It found that when rate decreases, rising head cannot offset lost by hydraulic loss, thus forming unstable gradually appears guide vane runner area. There phenomena, such separation, a sudden change radial pressure vaneless area runner; is, almost occupies whole due area, resulting deterioration instability operation. When large, mutation zone mainly exists cascades, making form an vortex. The can provide theoretical reference for improving stability pump-turbines.
Language: Английский
Citations
2