Changes between Version 6 and Version 7 of imuk/projects/2012_07

Timestamp:

Oct 31, 2013 10:33:16 AM (11 years ago)

Author:

boeske

Comment:

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imuk/projects/2012_07

@@ -4 +4 @@
 Duration: November 2011- May 2012\\
 
-The 5^th^ order advection scheme of Wicker and Skamarock (2002) - hereafter WS5 - is neither positive definite nor monotonic. In case of sharp gradients of a transported scalar, discretisation errors of WS5 can lead to non-physical negative values or unwanted amplification of initial extrema. In order to achieve positive definiteness or monotonicity so-called flux limiters can be used to correct the solutions given by WS5 (Skamarock (2006), Wang et al. (2009)). In this thesis two low-order flux limiters (positive definite and monotonic) for WS5 are investigated using 1D-simulations, focusing on shape preserving qualities of the modified scheme. With regard to a potential future implementation in PALM the increase in computing time caused by the flux limiters is evaluated.
+The 5^th^ order advection scheme of Wicker and Skamarock (2002) as it is implemented in PALM - hereafter WS5 - is neither positive definite nor monotonic. In case of sharp gradients of a transported scalar, discretisation errors of WS5 can lead to non-physical negative values or unwanted amplification of initial extrema. In order to achieve positive definiteness or monotonicity so-called flux limiters can be used to correct the solutions given by WS5 (Skamarock, 2006; Wang et al., 2009). In this thesis two low-order flux limiters (positive definite and monotonic) for WS5 are investigated using 1D-simulations, focusing on shape preserving qualities of the modified scheme. With regard to a potential future implementation in PALM the increase in computing time caused by the flux limiters is evaluated.
 
 '''Download:''' [[attachment:bachelor_thesis.pdf|bachelor thesis]] (in German)\\