Main CfdTm Forum Saturne Aster ATAAC TWikiEditRaw editAttachPrint version

TWiki> Main Web>TWikiUsers>RuggeroPoletto>AgainReynStress (2010-06-03, RuggeroPoletto)

TWiki> Main Web>TWikiUsers>RuggeroPoletto>AgainReynStress (2010-06-03, RuggeroPoletto)

(1) |

The <uu> component, whose derivation may be found in this page, has to be semplified. In fact, in such a complex format, it is very difficult to make any consideration. We can multiply the fraction by and divide the summ as follows:

Since is independent from all the other terms we are allowed to average it separately and to substitute its own average:

(2) |

Since we know that we obtain:

If we now join again the sum under the average we notice that in the upper part there is almoust the radius formulation. In order to get it we add and subtract :

Since, by definition,

This is the final stage. The first consideration is that, even if semplified, it is very difficult to understand the way affects the results. In the old SEM, in fact, the shape function was chosen to satisfy has no contribution to the final Reynold Stress, which is instead controlled

These conditions, together with the following shape function: , help us in defining the A constant, which is:

Using the function created we have:

(Matlab result - see the script below!!)

I | Attachment | Action | Size | Date | Who | Comment |
---|---|---|---|---|---|---|

m | symbolic_calculatio_DFSEM.m | manage | 1.3 K | 2010-05-28 - 12:12 | RuggeroPoletto | |

m | symbolic_calculatio_shape_function.m | manage | 0.7 K | 2010-05-28 - 12:13 | RuggeroPoletto |

Topic revision: r3 - 2010-06-03 - 17:50:57 - RuggeroPoletto

Code_Saturne

KNOO

FLOMANIA

Photo Wall

Upcoming Events

Add Event

Copyright © by the contributing authors. Unless noted otherwise, all material on this web site is the property of the contributing authors.