Fully Parallel Environment for the Simulation of Unsteady Flow with Moving Boundary Components

Using the concept of overlapping mesh method for reference, a new method called as Overlapping Clouds of Points Method (OCPM) is firstly proposed to simulate unsteady flow with moving boundary problems based on meshless method. Firstly, a set of static background discrete points is generated in the whole calculation zone. Secondly, moving discrete points are created around moving body. According to the initial position of moving object in the flow field, the two sets of discrete points can be overlapped. With the motion of moving objects in the calculation field, moving discrete points around the moving body will inherently move. The exchange of flow field information between static points and moving points is realized by the solution of the clouds of points made up of static and moving discrete points using weighted meshless method nearby overlapping boundary. Four cases including piston problem, NACA0012 airfoil vibration flow around a moving sphere in supersonic and multibody separation are given to verify accuracy and practicability of OCPM. The numerical results agree well with exact solution and experimental results, which shows that the proposed OCPM can be applied to the simulation of unsteady flow problem.

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The LBE Simulation and PIV Experimental Study on a Novel Viscous Pump

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2005-77019 ◽

2005 ◽

Author(s):

Fan Yang ◽

Shuhong Liu ◽

Jinwei Li ◽

Yulin Wu

Keyword(s):

Boundary Condition ◽

Unsteady Flow ◽

Cross Sections ◽

Lattice Boltzmann ◽

Moving Boundary ◽

Flow Problem ◽

Numerical Study ◽

Reynolds Numbers ◽

Low Reynolds Numbers ◽

Moving Boundary Condition

A numerical study and PIV investigation of flow in a novel viscous-based pumping device appropriate for microscale applications is described. The device, essentially consisting of a rotating cylinder eccentrically placed in a channel, is shown to be capable of generating a net flow. The two shape cross-sections of cylinders, the circular and four semi-elliptic lobed contour are studied, which is the steady and unsteady flow problem, respectively. The lattice Boltzmann equation (LBE) simulations at low Reynolds numbers are carried out to study the influence of various geometric parameters, which the results are compared with the PIV experiment ones. The unified solid curved wall boundary condition based on interpolation and the balance of momentum on the wall of the LBE simulation is used in steady and unsteady flow, and the moving boundary condition is also used in the latter. The numerical results indicated that the more effective pumping and better performance is obtained with the decrease of Reynolds number, as well as the increase regular degree of cylinder cross-section.

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UNSTEADY FLOW IN A 3D CENTRALLY-ACTUATED TYPE ARTIFICIAL HEART

International Journal of Modern Physics C ◽

10.1142/s0129183107010553 ◽

2007 ◽

Vol 18 (05) ◽

pp. 783-793

Author(s):

X. L. YANG ◽

Y. LIU ◽

J. M. YANG

Keyword(s):

Unsteady Flow ◽

Vortex Ring ◽

Artificial Heart ◽

Moving Boundary ◽

Heart Beat ◽

Beat Rate ◽

Inlet Tube ◽

Blood Chamber ◽

Heart Beat Rate

The unsteady flow within a simplified 3D centrally-actuated type artificial heart was investigated numerically using moving boundary technique. The velocities on the inlet and outlet were determined according to the motion of the diaphragm. The case with heart beat rate of 75 beats per minute (bpm) was simulated. Two models were studied. It is found that, in the diastolic cycle, a vortex ring forms in the conjunction of the blood chamber and the inlet tube. This vortex ring can provide good wash-out on the wall.

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