Simulating Contra-Rotating Propellers in CONVERGE скачать в хорошем качестве

Simulating Contra-Rotating Propellers in CONVERGE

Contra-rotating propellers are pairs of coaxial propellers mounted on the same axis but rotating in opposite directions, which improves thrust efficiency and reduces rotational energy loss. These systems are frequently employed in industries such as aerospace, marine, and defense, where modeling their complex flow interactions is crucial for optimizing efficiency and assessing performance. However, the complex meshes around the rotating propellers and small propeller gaps pose challenges for accurate simulation. Further, these simulations require high levels of mesh refinement due to the complex moving geometries. CONVERGE’s autonomous meshing simplifies and reduces user meshing time to just a few minutes. Its unique cut-cell approach helps avoid cell skewness from geometry motion and allows the solver to maintain the aspect ratio, preventing additional numerical instabilities. CONVERGE’s Adaptive Mesh Refinement (AMR) can automatically refine the cells in certain areas to capture all the relevant physical phenomena, which minimizes computational cost and total wall time. Aerodynamic interactions between the two propellers can create turbulent flow and tip vortices, impacting the performance of the rear propeller. Additionally, the front propeller can generate a turbulent wake that affects the angle of attack of the rear propeller. To capture these effects, we used the RANS k-⍵ SST turbulence model. The first view (0:05-0:09) shows the two contra-rotating propellers rotating in opposing directions. In the second view (0:10-0:16), you can see the isosurfaces for the Q-criterion. The isosurfaces, which show the vortex, are colored by velocity. In the third view (0:17-0:24), the left panel presents the axial velocity on a vertical plane passing through the propellers, and the right panel shows the propeller blades colored by pressure coefficient. The fourth view (0:25-0:42) displays the axial, tangential, and radial velocities for the front (top) and rear (bottom) propellers. In the fifth view (0:43-0:50), the top panel shows the axial, tangential, and radial velocities in a plane directly behind the rear propeller, whereas the bottom panel shows a graph of the torque coefficient over two propeller rotations. Finally, the sixth view (0:51-0:59) highlights CONVERGE’s AMR capabilities. The slice is colored by velocity to show the automatic refinement of the mesh in regions of high velocity gradient. Convergent Science's CONVERGE is an innovative computational fluid dynamics (CFD) software that eliminates the grid generation bottleneck from the simulation process through autonomous meshing.