Bending Section Mesh
When designing a TEE probe, mesh is often placed under the bending rubber to prevent the ribs from puncturing the articulation section and adding structural stability. During repair, it may be necessary to remove the mesh.
Bending Section Mesh is a Blender feature that can be used to bend a single or multiple elements. It works by collapsing the Y and Z coordinates of the individual vertices, stretching them along a curve in X.
90-Degree Bends
Pipe bends are the most common type of bend found in piping systems and are designed to link tubes together at right angles to each other. Bending Section Mesh They are also known as 90 bends or 90 ells, and are used to change the direction of flow in a pipe.
The flow structure of a pipe depends on the radius and angle of the bend and can be complex. A study of the flow separation characteristics of a bend is important in determining the performance of a pipeline and minimizing losses.
Fig. 2 shows the normalized velocity profile of a k-e turbulent flow in a pipe bend for a number of different Reynolds numbers. The distribution of the velocity vector shows a significant secondary motion induced by the fluid movement from inner to outer wall of the bend leading to flow separation.
In addition to observing the velocity field of the flow, it is also possible to observe the flow separation region and corresponding reattachment points. These separation and reattachment points move upstream and downstream as Reynolds number increases, respectively.
A similar trend is observed for the rms profiles of the velocity fluctuation in both the x and the y directions for different Reynolds numbers. The peak values in the rms profile in x direction are nearly the same for the different Reynolds numbers, while the rms profiles in the y direction show a slight Reynolds number dependence.
This study was done to investigate the influence of Reynolds number on the flow separation and reattachment of single phase turbulent flow in a pipe bend using k-e turbulence model. The results indicate that the flow separation starts at a position near the bend inlet and moves upstream as the Reynolds number increases, while the reattachment point moves downstream.
It is interesting to note that this pattern appears in a range of frequencies that are significantly lower than the cut-off frequency for plane waves, which suggests that acoustical dissipation is not induced within the bend due to visco-thermal damping of the fluid in the bend.
These findings are consistent with the experimental observations in References.
The bending strain neutral layer shift for the two processes based on FEA is analyzed and it is found that for the RDB process the axis of the inward layer shift is aligned with the center line of the bend, while the axes of the inward layer shift are offset from the center line for the CB process. This difference in the bending strain neutral layer position could be attributed to the differences in the forming processes and tooling setups.
However, the average springback of both the processes is comparable for 30-degree and 90-degree bends. This can be attributed to the fact that springback mainly reflects relaxation of curvature, as compared to longitudinal Bending Section Mesh contraction, which could not be seen in a straight section of the pipe, due to the presence of a large amount of shear.
The reattachment of the fluid to the bend outlet is a complicated and unsteady phenomenon that can be observed in a wide range of Reynolds numbers. The reattachment region is a low velocity area that was found at the inner core of the bend outlet. The reattachment region is found to have three flow motions, which are highly complex and unsteady.
