Civil Engineering Reference
In-Depth Information
storka_pp
distributed storage of pm and km
storkb_pp
distributed storage of pm and km
The closest serial equivalent is Program 8.3. As in the previous program, geometry
restrictions are to a symmetrical quarter cuboidal box mesh which has zero potential on
all external faces. An initial condition of uniform potential
val0
is specified everywhere
else, and the decay of potential at the centre of the box with time is monitored.
Loops
elements_1
and
element_2
with its embedded
gauss_pts
can be traced
clearly between the serial and parallelised versions, as can loops
elements_3
and
elements_4
.
The problem analysed as shown in Figure 12.2 is for a quarter cube of unit size with an
initial potential of 100.0 units everywhere except at the external boundaries. Data are listed
as Figure 12.20 with results as Figure 12.21 and performance statistics as Figure 12.22
nels nxe nze nip
125000 50 50 8
aa bb cc kx ky kz
0.02 0.02 0.02 1.0 1.0 1.0
dtim nsteps theta
0.01 150 0.5
npri tol limit val0
10 0.0001 100 100.0
Figure 12.20
Data for Program 12.4 example
This job ran on 16 processors
There are 132651 nodes 7651 restrained and 125000 equations
Time after setup is : 0.510000000002037268
Time Pressure Iterations
0.1000E+00 0.8564E+02 21
0.2000E+00 0.4605E+02 19
0.3000E+00 0.2229E+02 14
0.4000E+00 0.1066E+02 13
0.5000E+00 0.5085E+01 12
.
.
.
0.1300E+01 0.1360E-01 10
0.1400E+01 0.6484E-02 10
0.1500E+01 0.3087E-02 10
This analysis took : 421.750000000000000
Figure 12.21
Results from Program 12.3 example
Mesh
No of Processors Analysis Time(secs)
50x50x50 8 840
16 422
Figure 12.22
Performance statistics: Program 12.4 (IBM SP2)
