scholarly journals Time-Fluid Field-Based Coordination

2020 ◽  
pp. 193-210
Author(s):  
Danilo Pianini ◽  
Stefano Mariani ◽  
Mirko Viroli ◽  
Franco Zambonelli
Keyword(s):  
Fluid Field

Transient Interaction of a Circular Plate and a Fluid Medium

1979 ◽  
Vol 46 (1) ◽  
pp. 26-30 ◽  
Author(s):  
J. W. Berglund
Keyword(s):  
Boundary Conditions ◽  
Circular Plate ◽  
Applied Pressure ◽  
Plate Boundary ◽  
Fluid Medium ◽  
Fluid Field ◽  
Elastic Circular Plate ◽  
Unstrained State ◽  
State Of Rest ◽  
Acoustic Fluid

The transient dynamic response of an elastic circular plate subjected to a suddenly applied pressure is determined for several edge boundary conditions. The plate boundary is attached to a semi-infinite, radially rigid tube which is filled with an acoustic fluid, and pressure is applied to the in-vacuo side of the plate. The transient solution is determined by using a technique in which the plate is subjected to a periodic pressure function constructed of appropriately signed and time-shifted Heaviside step functions, and by relying on a physical mechanism which returns the plate and fluid near the plate to an unstrained state of rest between pulses. The plate response is presented for a number of radius-to-thickness ratios and edge boundary conditions when interacting with water. Comparisons are also made with solutions obtained using a plane wave approximation to the fluid field.

Flow Passage Modification and Experimental Verification of a Multi-Stage Centrifugal Pump

2013 ◽  
Vol 753-755 ◽  
pp. 2766-2769
Author(s):  
Quan Zhang ◽  
Zhi Jun Shuai ◽  
Pan Zhou ◽  
Wan You Li
Keyword(s):  
Centrifugal Pump ◽  
Cfd Simulation ◽  
Acceleration Response ◽  
Vibration Acceleration ◽  
Flow Passage ◽  
Fluid Field ◽  
Multi Stage ◽  
Through Flow ◽  
Seat Vibration ◽  
Velocity Pressure

In this paper the seat vibration acceleration response was reduced through flow passage modification of the centrifugal pump which could decrease the fluid excitation of the pump. CFD simulation technology was applied to optimize the fluid field of the multi-stage centrifugal pump, and then the velocity, pressure fluctuation and fluid excitation were concerned to investigate the effect of optimization. Finally, the influence of fluid field modification on the seat vibration response was verified experimentally.

Grinding Fluid Flow Field Modeling and Multi-Parameter Numerical Analysis Based on Smooth Model

2010 ◽  
Vol 156-157 ◽  
pp. 948-955
Author(s):  
Guang Yao Meng ◽  
Ji Wen Tan ◽  
Yi Cui
Keyword(s):  
Fluid Flow ◽  
Numerical Analysis ◽  
Flow Field ◽  
Dynamic Pressure ◽  
Grinding Wheel ◽  
Lubricating Film ◽  
Fluid Field ◽  
Grinding Fluid ◽  
Smooth Model ◽  
Area Increase

Relative motion between grinding wheel and workpiece makes the lubricant film pressure formed by grinding fluid in the grinding area increase, consequently, dynamic pressure lubrication forms. The grinding fluid flow field mathematical model in smooth grinding area is established based on lubrication theory. The dynamic pressure of grinding fluid field, flow velocity and carrying capacity of lubricating film are calculated by the numerical analysis method. An analysis of effect of grinding fluid hydrodynamic on the total lifting force is performed, and the results are obtained.

Numerical Analysis of Flow Field Characteristics in Three-Z-Shaped Ultrasonic Flowmeter

2012 ◽  
Vol 226-228 ◽  
pp. 1829-1834 ◽  
Author(s):  
Jing Yuan Tang ◽  
Jian Ming Chen ◽  
Hong Bin Ma ◽  
Guang Yu Tang
Keyword(s):  
Flow Field ◽  
Cross Sections ◽  
Flow Direction ◽  
Fluid Velocity ◽  
Internal Flow ◽  
Reynolds Stress Model ◽  
Ultrasonic Flowmeter ◽  
Developed Turbulence ◽  
Fluid Field ◽  
Flow Field Characteristics

The flow field characteristics in U-typed bend has been extensively studied for transit time ultrasonic flowmeters designing, but for the flowmeter with three-Z-shaped round pipe there is still lack of corresponding research. This paper presents a computational fluid dynamics (CFD) approach for modeling of the three-Z-shaped ultrasonic flowmeter and studying of internal fluid field characteristics based on Reynolds stress model (RSM). The fluid velocity profile in the three ultrasound path is obtained using CFD and secondary flow in cross section also is analyzed. The simulation results show that the internal flow fields in the flowmeter are not fully developed turbulence with asymmetric axial velocity distribution and dramatic changes along the flow direction, and there are obvious secondary cross flows on theirs cross-sections. The CFD simulations provide useful insights into the flow field associated with ultrasonic flowmeters design.

A multi-scale E-Jet 3D printing regulated by structured multi-physics field

2021 ◽  
Author(s):  
Kai Li ◽  
Yihui Zhao ◽  
Maiqi Liu ◽  
Xiaoying Wang ◽  
Fangyuan Zhang ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
3D Printing ◽  
Aspect Ratio ◽  
Process Parameters ◽  
High Aspect Ratio ◽  
Thermal Field ◽  
Structural Features ◽  
Microfluidic Chips ◽  
Multi Scale ◽  
Fluid Field

Abstract Micro/nano scale structure as important functional part have been widely used in wearable flexible sensors, gas sensors, biological tissue engineering, microfluidic chips super capacitors and so on. Here a multi-scale electrohydrodynamic jet (E-Jet) 3D printing approach regulated by structured multi-physics fields was demonstrated to generate 800 nm scale 2D geometries and high aspect ratio 3D structures. The simulation model of jetting process under resultant effect of top fluid field, middle electric field and bottom thermal field was established. And the physical mechanism and scale law of jet formation were studied. The effects of thermal field temperature, applied voltage and flow rate on the jet behaviors were studied; and the range of process parameters of stable jet was obtained. The regulation of printing parameters was used to manufacture the high resolution gradient graphics and the high aspect ratio structure with tight interlayer bonding. The structural features could be flexibly adjusted by reasonably matching the process parameters. Finally, PCL/PVP composite scaffolds with cell-scale fiber and ordered fiber spacing were printed. The proposed E-Jet printing method provides an alternative approach for the application of biopolymer materials in tissue engineering.

scholarly journals Three-Dimensional Path Planning of Constant Thrust Unmanned Aerial Vehicle Based on Artificial Fluid Method

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yongqiang Qi ◽  
Shuai Li ◽  
Yi Ke
Keyword(s):  
Path Planning ◽  
Unmanned Aerial Vehicle ◽  
Interpolation Method ◽  
Three Dimensional ◽  
Planning Problem ◽  
Perturbation Matrix ◽  
Fluid Field ◽  
Control Scheme ◽  
Aerial Vehicle ◽  
Tangential Vector

In this paper, a three-dimensional path planning problem of an unmanned aerial vehicle under constant thrust is studied based on the artificial fluid method. The effect of obstacles on the original fluid field is quantified by the perturbation matrix, the streamlines can be regarded as the planned path for the unmanned aerial vehicle, and the tangential vector and the disturbance matrix of the artificial fluid method are improved. In particular, this paper addresses a novel algorithm of constant thrust fitting which is proposed through the impulse compensation, and then the constant thrust switching control scheme based on the isochronous interpolation method is given. It is proved that the planned path can avoid all obstacles smoothly and swiftly and reach the destination eventually. Simulation results demonstrate the effectiveness of this method.

scholarly journals Unsteady Flow and Vibration Analysis of the Horizontal-Axis Wind Turbine Blade under the Fluid-Structure Interaction

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Rui Zhu ◽  
Da-duo Chen ◽  
Shi-wei Wu
Keyword(s):  
Unsteady Flow ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Wind Turbine Blade ◽  
Horizontal Axis ◽  
Leeward Side ◽  
Horizontal Axis Wind Turbine ◽  
Fluid Structure ◽  
Fluid Field ◽  
Stress Fluctuation

A 1.5 MW horizontal-axis wind turbine blade and fluid field model are established to study the difference in the unsteady flow field and structural vibration of the wind turbine blade under one- and two-way fluid-structure interactions. The governing equations in fluid field and the motion equations in structural were developed, and the corresponding equations were discretized with the Galerkin method. Based on ANSYS CFX fluid dynamics and mechanical structural dynamics calculation software, the effects of couplings on the aerodynamic and vibration characteristics of the blade are compared and analyzed in detail. Results show that pressure distributions at different sections of the blade are concentrated near the leading edge, and the leeward side of two-way coupling is slightly higher than that of one-way coupling. Deformation along the blade span shows a nonlinear change under the coupling effect. The degree of amplitude attenuation in two-way coupling is significantly greater than that in one-way coupling because of the existence of aerodynamic damping. However, the final amplitude is still higher than the one-way coupling. The Mises stress fluctuation in the windward and leeward sides is more obvious than one-way coupling, and the discrepancy must not be ignored.

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