Bob’s Research Corner: Grid Def – Twist

In this post, I’ll present the twisting results of my grid deformation code.  I’ve taken the same grids (Onera M6 wing and the F-18C vertical tail) and applied a twist along the mid-chord.  For information about the grids and the bending results, you can read “Bob’s Research Corner: Grid Def – Bending”.  Twisting along the mid-chord is based on the square of the span location times a maximum twist angle.

On the Onera M6 wing, the maximum twist angle achieved before encountering folded faces was 10.5 degrees. The maximum twist occurs at the wing tip.  This is an ok twist amount just like the bending result.  The results are shown below, first with a video of the wing twisting over 25 time-steps followed by still images comparing the original versus deformed grid.  The original grid is shown in red while the deformed grid is shown in blue.

For the F-18C vertical tail, I could only reach a disappointing 1.15 degrees before the grid became invalid. The video below shows the twisting of the tail over 25 time-steps — look closely or you will miss it. Still images of the original versus deformed grids are also presented. The original grid is shown in red while the deformed grid is shown in blue.

Work continues on the unfolding of folded faces algorithm. When it does work, I can get quite a bit more deformation then I’ve presented so far. I hope to have an update showing the bending results next month.

Posted in News.

Bob Tomaro

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