|
[Sponsors] |
January 5, 2011, 15:54 |
When to switch to 3D CFD
|
#1 |
New Member
Mitch Alsup
Join Date: Nov 2010
Location: Austin Texas
Posts: 1
Rep Power: 0 |
Since Oct., I have been doing 1D CFD on an automobile engine and have made a lot of progress.
However, I am finding the 1D CFD is leading me in direction opposite that taken by the std. textbooks on airflow through engines on a couple of engine airflow topics. For example, I get better response (TQ and HP) when making a helmholtz resonator just big enough to completely cover the velocity stack trumpet (about 1 litre in the HR), and that my exhaust header pipes (primary, secondary, and expansion chamber) are longer than what the std texts describe. With respect to the helmholtz resonator in particular, the length of the HR neck is very short compared to the width of the neck (L on the order of 10mm w; on the order of 60mm). Is this one of the kinds of simulations that needs 3D aspects accurately modeled because of the 'end effects' of resonating masses in short pipes? In particular, the HR resonator is barely bigger (2X in volume) than the trumpet on the velocity stack that reside inside of it. So, while I modeled the overall shape of a HR resonator with nice gentle curves, I'm not sure that the 1D models what might really happen. So the question is:: At what point does it become profitable to switch from the simple 1D world to the world of 3D CFD? Where profit is defined as: making forward progress faster Thanks Mitch |
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
STAR-Works : Mainstream CAD with CFD | CD adapco Group Marketing | Siemens | 0 | February 13, 2002 12:23 |
Where do we go from here? CFD in 2001 | John C. Chien | Main CFD Forum | 36 | January 24, 2001 21:10 |
CFD job and salary? | Mingyong | Main CFD Forum | 11 | January 2, 2001 06:15 |
Since Last June | John C. Chien | Main CFD Forum | 3 | July 12, 1999 09:38 |
Which is better to develop in-house CFD code or to buy a available CFD package. | Tareq Al-shaalan | Main CFD Forum | 10 | June 12, 1999 23:27 |