l16 - Lecture 16: Diffusion on Unstructured Meshes (Contd)...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Lecture 16: Diffusion on Unstructured Meshes (Cont’d)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Last Time … Last time, we: Saw that we need to find gradients for secondary flux calculation (and for other reasons) Saw that finding gradients is relatively simple on structured meshes Used gradient theorem approach to find cell-centroid gradient on unstructured mesh
Background image of page 2
3 This Time… We will Look at another way to find gradients on unstructured meshes » Least squares method Discussion of the effect of secondary gradient calculation on coefficient structure and convergence Implementation issues
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 Least Squares Method for Gradient Calculation Estimate values at neighboring cell-centroids assuming local linearity and using cell gradient at C0 Figure out an “error” in the estimate Find gradient components at C0 to minimize error
Background image of page 4
5 Least Squares Method (Cont’d) Let’s assume that local variation is linear We can estimate value at C1 centroid as:
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
6 Least Squares Method (Cont’d) Can do similar manipulation at all face centroids j=1,2,…,J: Can write a set of equations where M is Jx2 matrix
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 22

l16 - Lecture 16: Diffusion on Unstructured Meshes (Contd)...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online