|
[Sponsors] |
January 4, 2006, 13:29 |
Transient analysis
|
#1 |
Guest
Posts: n/a
|
Im running a transient analysis and am using the CFX code for working averaged navier stokes for an aeracoustic analysis.
INSUFFICIENT MEMORY ALLOCATED *** | | Action required : Increase the character stack memory size. Thats the error i keep getting, i have increased it in the solver parameters to 1.2, then 1.5 but still the same error coming up. I am using Sun system machines (blade 2500), is it my analysis is too big (24,000 timesteps) or am i doing something else wrong? I have just started it again with the memory stack parameter set at 2.5. Posting this now as each one of these runs is taking about a week. |
|
January 4, 2006, 14:17 |
Re: Transient analysis
|
#2 |
Guest
Posts: n/a
|
Do you run your job in serial or parallel? If in parallel, how many nodes have you put on each partition? What are the CPU and OS on your machine?
|
|
January 4, 2006, 18:20 |
Re: Transient analysis
|
#3 |
Guest
Posts: n/a
|
It is in serial, unfortunately we do not have parallel licences. The CPU is 1.6GHz with 2Gig Dimm memory on a solaris 9 unix work system. I am using ANSYS CFX 10
|
|
January 4, 2006, 18:53 |
Re: Transient analysis
|
#4 |
Guest
Posts: n/a
|
I suggest just increas the <font color=red>character</font> stack memory size, instead of total . you should expand the detail items, and set<font color=red> 1.5x</font> (or other factor)for column character only.
|
|
January 4, 2006, 19:20 |
Re: Transient analysis
|
#5 |
Guest
Posts: n/a
|
i have already reduced it, i should hae said 2x and 4x in my post, sorry. It was originally crashing at about 4000 iterations, i increased the stack size to 2x and it went to 8000, and i am waiting for the results from a size of 4x.
|
|
January 4, 2006, 22:55 |
Re: Transient analysis
|
#6 |
Guest
Posts: n/a
|
The fact that you have to adjust memory size indicates that your job is too big to run efficiently in serial on the machine you are using now. Adjusting memory size is a short term solution. You probably want to consider either increasing physical memory on your machine or getting parallel license. CFX 10 has very good parallel performance, which can significantly reduce running time.
|
|
January 5, 2006, 05:40 |
Re: Transient analysis
|
#7 |
Guest
Posts: n/a
|
Try running your problem in smaller lots. e.g. from step 1 to 2000, 2000 to 4000 etc.
|
|
January 5, 2006, 12:35 |
Re: Transient analysis
|
#8 |
Guest
Posts: n/a
|
thankyou, i will continue to hassle my uni to get the parallel licences
|
|
January 6, 2006, 10:55 |
Re: Transient analysis
|
#9 |
Guest
Posts: n/a
|
Tried your suggestion TB, and i have managed to get it up to 9000 timesteps using two batches, memeory stack of 3.5 and only 5 coeff loops.Thankyou
|
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
2-D airfoil transient analysis | mike | FLUENT | 1 | July 15, 2017 05:33 |
FSI Transient Thermal Analysis | Abduri | CFX | 1 | January 1, 2017 23:54 |
Import transient cfx-results for static structural analysis in Ansys WB 13 | Colt Seavers | ANSYS | 1 | August 11, 2011 07:01 |
Transient Thermal Analysis in Ansys Workbench | khurram1 | ANSYS | 0 | November 22, 2010 03:40 |
transient analysis of silencer using cfx. | mehul | CFX | 0 | October 16, 2005 05:48 |