Hi guys, iam trying to mesh a human artery model using unstructured hex mesh but when i increase the mesh density i get lot of negative volume cells, iam not sure how to overcome this problem.

1. How do you increase the density ? 2. Are those cells also Left handed ? 3. Why unstructured Hex ??

All the cells are right handed. one can increase the density by refining the mesh using the option in star guide. I need Trimmed mesh (Unstructured mesh)for my application.