Modeling of Turbine Rotor Journal Machining with Location on Bearing and with Center Pregrinding

To investigate the optimum layouts of small vertical-axis wind turbines, a two-dimensional analysis of dynamic fluid body interaction is performed via computational fluid dynamics for a rotor pair in various configurations. The rotational speed of each turbine rotor (diameter: D = 50 mm) varies based on the equation of motion. First, the dependence of rotor performance on the gap distance (gap) between two rotors is investigated. For parallel layouts, counter-down (CD) layouts with blades moving downwind in the gap region yield a higher mean power than counter-up (CU) layouts with blades moving upwind in the gap region. CD layouts with gap/D = 0.5–1.0 yield a maximum average power that is 23% higher than that of an isolated single rotor. Assuming isotropic bidirectional wind speed, co-rotating (CO) layouts with the same rotational direction are superior to the combination of CD and CU layouts regardless of the gap distance. For tandem layouts, the inverse-rotation (IR) configuration shows an earlier wake recovery than the CO configuration. For 16-wind-direction layouts, both the IR and CO configurations indicate similar power distribution at gap/D = 2.0. For the first time, this study demonstrates the phase synchronization of two rotors via numerical simulation.

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Surrogate-Based Optimization of Horizontal Axis Hydrokinetic Turbine Rotor Blades

Energies ◽

10.3390/en14134045 ◽

2021 ◽

Vol 14 (13) ◽

pp. 4045

Author(s):

David Menéndez Arán ◽

Ángel Menéndez

Keyword(s):

Turbine Blade ◽

Design Method ◽

Optimization Method ◽

Turbine Rotor ◽

Computational Effort ◽

Rotor Blades ◽

Linear Functions ◽

Cavitation Inception ◽

Hydrokinetic Turbine ◽

Blade Geometry

A design method was developed for automated, systematic design of hydrokinetic turbine rotor blades. The method coupled a Computational Fluid Dynamics (CFD) solver to estimate the power output of a given turbine with a surrogate-based constrained optimization method. This allowed the characterization of the design space while minimizing the number of analyzed blade geometries and the associated computational effort. An initial blade geometry developed using a lifting line optimization method was selected as the base geometry to generate a turbine blade family by multiplying a series of geometric parameters with corresponding linear functions. A performance database was constructed for the turbine blade family with the CFD solver and used to build the surrogate function. The linear functions were then incorporated into a constrained nonlinear optimization algorithm to solve for the blade geometry with the highest efficiency. A constraint on the minimum pressure on the blade could be set to prevent cavitation inception.

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A linear cascade tunnel for flow investigations of steam turbine rotor tip blades in subsonic nucleating flows

SN Applied Sciences ◽

10.1007/s42452-021-04291-3 ◽

2021 ◽

Vol 3 (2) ◽

Author(s):

Vital Kumar Yadav Pillala ◽

B. V. S. S. S. Prasad ◽

N. Sitaram ◽

M. Mahendran ◽

Debasish Biswas ◽

...

Keyword(s):

Steam Turbine ◽

Turbine Rotor ◽

Turbine Cascade ◽

Flow Measurements ◽

Linear Cascade ◽

Dry Air ◽

Steam Turbine Rotor ◽

Pressure Distributions ◽

Working Medium ◽

Exit Mach Number

AbstractThe paper presents details of a unique experimental facility along with necessary accessories and instrumentation for testing steam turbine cascade blades in wet and nucleating steam. A steam turbine rotor tip cascade is chosen for flow investigations. Cascade inlet flow measurements show uniform conditions with dry air and steam and dry air mixture of different ratios. Exit flow surveys indicate that excellent flow periodicity is obtained. Blade surface static pressure and exit total pressure distributions are also presented with dry air and with steam and dry air mixture of different ratios as the working medium at an exit Mach number of 0.52.

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