Straight-leaned blade aerodynamics of a turbine nozzle blade row with low span-diameter ratio

2000 ◽  
Vol 9 (1) ◽  
pp. 51-62 ◽  
Author(s):  
N. X. Chen ◽  
Y. J. Xu ◽  
W. G. Huang
Keyword(s):  
Diameter Ratio ◽  
Blade Row ◽  
Nozzle Blade

scholarly journals Detailed Design and Aerodynamic Performance Analysis of a Radial-Inflow Turbine

2018 ◽  
Vol 8 (11) ◽  
pp. 2207 ◽  
Author(s):  
Amir Karimi Noughabi ◽  
Shervin Sammak
Keyword(s):  
Aerodynamic Performance ◽  
Preliminary Design ◽  
Analysis Method ◽  
Aerodynamic Design ◽  
Ansys Cfx ◽  
Blade Row ◽  
Radial Inflow Turbine ◽  
Critical Components ◽  
Full Design ◽  
Nozzle Blade

Radial-inflow turbines (RI turbines) are critical components of air cycle machines (ACM), utilized in environment conditioning systems (ECS). In this work, a process is presented for the full design of a radial-inflow turbine, including volute, nozzle blade row and rotor blade row. The preliminary and detailed aerodynamic design approaches are explained in detail. A mean-line (1D) analysis method coupled with the preliminary design is employed to evaluate the aerodynamic performance of the RI turbine. Then, ANSYS CFX is used to perform unsteady 3D simulations of the designed RI turbine at design and off-design conditions to predict the aerodynamic performance of the turbine for future optimization.

Ortho-k lenses fitting in patients with “non-typical” corneas

The Eye ◽  
2020 ◽  
Vol 22 (129) ◽  
pp. 22-29
Author(s):  
Svetlana Kravchuk ◽  
Olga Zhabina
Keyword(s):  
Correction Method ◽  
Diameter Ratio ◽  
Corneal Curvature ◽  
Individual Approach ◽  
Fitting In ◽  
Corneal Diameter ◽  
Clinical Cases

We described two clinical cases of ortho-k lenses fitting in patients with “non-typical” corneal curvature/diameter ratio. The main goal was to acknowledge effective and safe use of this myopia correction method in patients with corneal diameter greater than 11 mm. Individual approach to each patient is the key to a successful and safe ortho-k lenses fitting.

Adaptive Eye Fundus Vessel Classification for Automatic Artery and Vein Diameter Ratio Evaluation

Informatica ◽  
2018 ◽  
Vol 29 (4) ◽  
pp. 757-771 ◽  
Author(s):  
Giedrius Stabingis ◽  
Jolita Bernatavičienė ◽  
Gintautas Dzemyda ◽  
Alvydas Paunksnis ◽  
Lijana Stabingienė ◽  
...  
Keyword(s):  
Diameter Ratio ◽  
Vein Diameter

Design of a slender turning cutting tool via a vibration absorber equipped with piezoelectric ceramic

2021 ◽  
pp. 107754632110144
Author(s):  
Yiqing Yang ◽  
Haoyang Gao ◽  
Qiang Liu
Keyword(s):  
Piezoelectric Ceramic ◽  
Cutting Tool ◽  
Vibration Suppression ◽  
Equations Of Motion ◽  
Electrical Energy ◽  
Diameter Ratio ◽  
Vibration Absorber ◽  
Machined Surface ◽  
Structural Part ◽  
Machined Surface Roughness

Turning cutting tool with large length–diameter ratio has been essential when machining structural part with deep cavity and in-depth hole features. However, chatter vibration is apt to occur with the increase of tool overhang. A slender turning cutting tool with a length–diameter ratio of 7 is developed by using a vibration absorber equipped with piezoelectric ceramic. The vibration absorber has dual functions of vibration transfer to the absorber mass and vibration conversion to the electrical energy via the piezoelectric effect. Equations of motion are established considering the dual damping from the piezoelectric ceramic and rubber gasket. The equivalent damping of piezoelectric ceramic is derived, and the geometries are optimized to achieve optimal vibration suppression. The modal analysis demonstrates that the cutting tool with the vibration absorber can reach 80.1% magnitude reduction. Machining tests are carried out in the end. The machining acceleration and machined surface roughness validate the vibration suppression of the VA, and the output voltage by the piezoelectric ceramic demonstrates the ability of vibration sensing.

Aerodynamic Asymmetry Analysis of Unsteady Flows in Turbomachinery

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Kivanc Ekici ◽  
Robert E. Kielb ◽  
Kenneth C. Hall
Keyword(s):  
Harmonic Balance ◽  
Coupling Effect ◽  
Unsteady Flows ◽  
Unsteady Aerodynamic ◽  
Blade Row ◽  
Balance Technique ◽  
Turbomachinery Blades ◽  
Aerodynamic Asymmetry ◽  
Frequency Domain Approach ◽  
Harmonic Balance Technique

A nonlinear harmonic balance technique for the analysis of aerodynamic asymmetry of unsteady flows in turbomachinery is presented. The present method uses a mixed time-domain/frequency-domain approach that allows one to compute the unsteady aerodynamic response of turbomachinery blades to self-excited vibrations. Traditionally, researchers have investigated the unsteady response of a blade row with the assumption that all the blades in the row are identical. With this assumption the entire wheel can be modeled using complex periodic boundary conditions and a computational grid spanning a single blade passage. In this study, the steady/unsteady aerodynamic asymmetry is modeled using multiple passages. Specifically, the method has been applied to aerodynamically asymmetric flutter problems for a rotor with a symmetry group of 2. The effect of geometric asymmetries on the unsteady aerodynamic response of a blade row is illustrated. For the cases investigated in this paper, the change in the diagonal terms (blade on itself) dominated the change in stability. Very little mode coupling effect caused by the off-diagonal terms was found.

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