scholarly journals Aeromechanical Optimization of First Row Compressor Test Stand Blades

2019 ◽  
Author(s):  
Mohammad Ghalandari ◽  
Alireza Ziamolki ◽  
Amir Mosavi ◽  
Shahab Shamshirband ◽  
Kwok-Wing Chau
Keyword(s):  
Fluid Dynamics ◽  
Essential Role ◽  
Forced Vibrations ◽  
The Self ◽  
Geometrical Parameters ◽  
Force Response ◽  
Test Rig ◽  
Matlab Code ◽  
Computational Fluid Dynamics Cfd ◽  
Surge Line

In this study, an optimization of the first blade in new test rig presented. Blade tuning is conducted using 3D geometrical parameters. Sweep and dihedral play an essential role in this study. Compressor characteristics and blades vibrational behavior are the main objective of the evaluation. Here, the attachments are designed to isolate blade dynamics from Disk. So, the Vibrational behaviors of the one's blade are tuned based on the self-excited and forced vibration phenomenon. Using a semi analytical MATLAB code instability conditions are satisfied. The code takes advantages of whitehead and force response theory to predict classically and stall flutter speeds. Beside, Forced vibrations instability is controlled using a theory presented by Campbell. Aerodynamics of new blade geometry determined using multistage simulations Computational fluid dynamics (CFD) software. Numerical results show increasing performance near the surge line and working interval along with increasing mass flow.

scholarly journals Studies on thickened tailings deposition in flume tests using the computational fluid dynamics (CFD) method

2019 ◽  
Vol 56 (2) ◽  
pp. 249-262
Author(s):  
Jinglong Gao ◽  
Andy Fourie
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Slope Angle ◽  
Geometrical Parameters ◽  
Flume Tests ◽  
Volume Energy ◽  
Computational Fluid Dynamics Cfd ◽  
Sudden Release ◽  
Cfd Method ◽  
Thickened Tailings

Computational fluid dynamics (CFD) simulations of laboratory flume tests on thickened tailings were conducted to highlight the factors that may influence the slopes of final profiles achieved in such flumes. The numerical model was first validated against the analytical solution of a sheet of Bingham fluid on a flat plane at flow stoppage. It was then used to investigate the influence of several factors on the average slopes of the final profiles. The results show that an increase of volume, energy, flume width or base angle reduces the resulting slope angle. Moreover, the yield stress of the fluid generally has more influence on the final profiles than the viscosity. In addition, the viscosity tends to have less influence on the formation of the final profiles if the inertial effects are relatively weak. Finally, two dimensionless parameters are proposed to establish the relationship between the average slope, rheological properties, and geometrical parameters for planar deposition of thickened tailings in both sudden-release (S-R) and discharge flume tests. These results provide a better understanding of the deposition of thickened tailings in the field. The agreement between simulation results and laboratory observations in the literature gives confidence in the veracity of the computational results.

scholarly journals Numerical and Experimental Investigation of Oil-Guiding Splash Lubrication in Light Helicopter’s Reducers

Aerospace ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 345
Author(s):  
Mei Yin ◽  
Xi Chen ◽  
Yu Dai ◽  
Duan Yang ◽  
Lanjin Xu ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Experimental Investigation ◽  
Great Influence ◽  
Test Rig ◽  
Specific Test ◽  
Rotating Speed ◽  
Lubrication Performance ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Oil Jet

Limited by the space and weight of the reducer, it is difficult to use traditional oil-jet lubrication and splash lubrication for a light helicopter, so an oil-guiding splash lubrication method is adopted as a research object in this paper. Firstly, the lubrication performance of the oil-guiding cylinder in the main reducer under different rotating speeds, oil levels, and flight attitudes is investigated based on the computational fluid dynamics (CFD) method. Then, a specific test rig is developed, and lubrication tests are carried out to verify the feasibility and correctness of the simulation. These results show that oil level, rotating speed, and flight attitude have a great influence on splash lubrication performance.

Self-Noise Analysis of Four-Electrode Microflow-Electrochemical Accelerometer Inspired by Hemodynamic Model

2013 ◽  
Vol 461 ◽  
pp. 984-992 ◽  
Author(s):  
Qiu Zhan Zhou ◽  
Da Yi Li ◽  
Yu Jiang Wang
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Noise Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
The Self ◽  
Geometrical Parameters ◽  
Dynamics Model ◽  
Hemodynamic Model ◽  
Three Dimensional Finite Element

A fluid dynamics model of electrolyte in mircroflow inspired by hemodynamic model of aortic is proposed and applied in the self-noise analysis of four-electrode microflow-electrochemical accelerometer. Three-dimensional finite element model is established and invested through numerical simulation, the variety of geometrical parameters on different location of electrode and varied time are considered, which can affect the microflow-electrochemical accelerometers self-noise. The result of numerical simulation indicates that, self-noise is related to electrode configuration as well as electrode geometrical parameters. In particular, convection-induced self-noise is correlated to variety of viscosity, and thermohydrodynamic self-noise is correlated to variety of diameter. Such a fluid dynamics model of electrolyte inspired by thermodynamics model can be also used for optimization of the self-noise.

Numerical Study of a Six-Bladed Savonius Wind Turbine

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Binyet Emmanuel ◽  
Wang Jun
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Study ◽  
The Self ◽  
Power Coefficient ◽  
Two Dimensional ◽  
Savonius Rotor ◽  
Convex Part ◽  
Computational Fluid Dynamics Cfd ◽  
Savonius Wind Turbine

The aim of the present paper is to investigate ways of improving the efficiency of a six-bladed Savonius rotor. The efficiency of Savonius machines is low because of the “negative drag” exerted on the convex part of the blades and also because the torque of standard Savonius rotors varies substantially during one rotation and therefore affects the self starting of the rotor at certain wind angles. Improvement of the efficiency of the Savonius rotor is carried out by increasing the number of blades and also by preventing the wind from impinging on the convex parts. The latter can be done by hiding the convex part of the blades behind a shield or a vane. The present paper shows the results of two-dimensional computational fluid dynamics (CFD) computations, indicating a promising increase of the power coefficient from 0.3 to 0.5.

scholarly journals Aircraft Icing Severity Evaluation

Encyclopedia ◽  
2022 ◽  
Vol 2 (1) ◽  
pp. 56-69
Author(s):  
Sibo Li ◽  
Roberto Paoli
Keyword(s):  
Artificial Intelligence ◽  
Fluid Dynamics ◽  
The Self ◽  
Nonlinear Mapping ◽  
Ice Accretion ◽  
Computer Algorithms ◽  
Aircraft Icing ◽  
Aerodynamic Performances ◽  
Computational Fluid Dynamics Cfd ◽  
Aerodynamic Configuration

Aircraft icing refers to the ice buildup on the surface of an aircraft flying in icing conditions. The ice accretion on the aircraft alters the original aerodynamic configuration and degrades the aerodynamic performances and may lead to unsafe flight conditions. Evaluating the flow structure, icing mechanism and consequences is of great importance to the development of an anti/deicing technique. Studies have shown computational fluid dynamics (CFD) and machine learning (ML) to be effective in predicting the ice shape and icing severity under different flight conditions. CFD solves a set of partial differential equations to obtain the air flow fields, water droplets trajectories and ice shape. ML is a branch of artificial intelligence and, based on the data, the self-improved computer algorithms can be effective in finding the nonlinear mapping relationship between the input flight conditions and the output aircraft icing severity features.

Le premier moment de l’art dans À la recherche du temps perdu de Marcel Proust – une « leçon d’idéalisme » ?

2020 ◽  
pp. 25-40
Author(s):  
Larisa Botnari
Keyword(s):  
Essential Role ◽  
Marcel Proust ◽  
The Self ◽  
Philosophy Of Art ◽  
The Novel ◽  
Philosophical Interpretation ◽  
German Philosopher ◽  
Lost Time ◽  
Aesthetic Thinking

Although very famous, some key moments of the novel In Search of Lost Time, such as those of the madeleine or the uneven pavement, often remain enigmatic for the reader. Our article attempts to formulate a possible philosophical interpretation of the narrator's experiences during these scenes, through a confrontation of the Proustian text with the ideas found in the System of Transcendental Idealism (1800) of the German philosopher F. W. J. Schelling. We thus try to highlight the essential role of the self in Marcel Proust's aesthetic thinking, by showing that the mysterious happiness felt by the narrator, and from which the project of creating a work of art is ultimately born, is similar to the experiences of pure self-consciousness evoked and analyzed by Schellingian philosophy of art.

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