Numerical Investigation on Hydrodynamic Behavior of Single Cylinder and Dual Coaxial-Cylinder System Using Cfd

2021 ◽  
Author(s):  
Pengfei Zhi ◽  
Xinshu Zhang ◽  
Ke Chen ◽  
Ronald W. Yeung
Keyword(s):  
Numerical Investigation ◽  
Coaxial Cylinder ◽  
Hydrodynamic Behavior ◽  
Single Cylinder

Numerical Investigation of Heaving Hydrodynamic Behavior of a Single Cylinder and a Dual Coaxial-Cylinder System Using CFD

2020 ◽  
Author(s):  
Pengfei Zhi ◽  
Xinshu Zhang ◽  
Ke Chen ◽  
Ronald W. Yeung
Keyword(s):  
Outer Cylinder ◽  
Mesh Size ◽  
Computer Code ◽  
Coaxial Cylinder ◽  
Hydrodynamic Performance ◽  
Hydrodynamic Coefficients ◽  
Hydrodynamic Behavior ◽  
Time Step ◽  
Cfd Models ◽  
Free Decay

Abstract In this paper, we apply a CFD computer code to study the hydrodynamic behavior of a stand-alone cylinder and a dual coaxial-cylinder system (DCCS) via free-decay motion tests. The geometric proportions of a stand-alone cylinder and the inner and outer cylinder of the DCCS are chosen to be the same as those in [1] and [2], respectively, as ocean wave-energy converter (WEC) devices. Overset mesh based on the commercial code ‘Star-CCM+ 11’ is used to simulate the free-decay motion of the two systems. Five parameters chosen for the CFD implementation are: turbulence model, initial displacement, time step, number of prism layers and mesh size. Results obtained from using different values of these parameters are compared so as to confirm the validity of choices made. The hydrodynamic performance of the stand-alone cylinder and outer cylinder in the DCCS are compared with the experimental results to assess and validate the CFD models. In addition, the heave hydrodynamic coefficients, namely, the added mass and total damping, and ‘resonance’ frequency of the stand-alone cylinder and those of the inner cylinder of the DCCS, with the outer cylinder being fixed, are obtained by using the CFD procedure. The hydrodynamic coefficients of another stand-alone cylinder with the same dimensions as the inner cylinder of the dual-coaxial cylinder are also obtained by simulations. The vorticity-contour plots for the stand-alone cylinder and the outer cylinder in the DCCS in free-decay motion are presented and analyzed. Finally, the results of the three cases are compared to examine the effect of the outer cylinder on the heave hydrodynamic coefficients of the inner cylinder.

Experimental and Numerical Investigation of a Passive Pre-Chamber Jet Ignition Single-Cylinder Engine

2021 ◽  
Author(s):  
Federico Millo ◽  
Luciano Rolando ◽  
Andrea Piano ◽  
Paolo Sementa ◽  
Francesco Catapano ◽  
...  
Keyword(s):  
Numerical Investigation ◽  
Single Cylinder ◽  
Single Cylinder Engine

Numerical investigation of combustion characteristics of a four-stroke single cylinder CI engine under various turbulence models

2019 ◽  
pp. 1-7
Author(s):  
G. Sugash ◽  
Itham Sasi Vardhan Venkat ◽  
Mynampati Vijay Reddy ◽  
Shaik Riyaz Ali ◽  
Jitendra Harsha Sai Krishna
Keyword(s):  
Numerical Investigation ◽  
Turbulence Models ◽  
Combustion Characteristics ◽  
Single Cylinder ◽  
Ci Engine

A Numerical Investigation on Reduction of Fluid Force on Three Dimensional Circular Cylinder with Tripping Rods

2011 ◽  
Vol 105-107 ◽  
pp. 139-142
Author(s):  
Chao Ying Zhou ◽  
Wen Ying Ji ◽  
Xing Wei Zhang
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Numerical Investigation ◽  
Angular Position ◽  
Three Dimensional ◽  
Fluid Force ◽  
Single Cylinder ◽  
Fluid Forces ◽  
Optimum Angle ◽  
Optimum Position

The effects of tripping rods on characteristics and fluid forces acting on a single cylinder was three-dimensional numerical studied in a low laminal flow at a Reynolds number of 200 and a subcritical stream at a Reynolds number of 5.5X104. The angular position of the tripping rods was varied from 20 to 60.The results reveal that there exits an optimum position of tripping rod for reducing fluid forces. This optimum angular position was found to be 40° for Re=200 and 30° for Re=5.5X104. At this optimum angle, the steady drag, fluctuating drag and fluctuating lift forces acting on the cylinder are reduced by 21%, 32%, and 28% for Re=200 and 36%, 44%, 76% for Re=5.5X104.

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