Shure,

so i have an centrifugal impeller.

To demonstrate the problem with second order elements, it is as simple as possible.

I have meshed with the basic meshing setup. Second order elements active and set the element size to a reasenable value. Only one refinement was done at the rim of the impeller to assure enough geometry resolution. There is a fixed BC on the Hub, as shown in the sceenshot. The impeller rotates with 300 rad/s around the z axis.

When i solve this model, the monitor is showing this message:

The numbers below are estimated upper bounds

number of:

nodes: 1479192

elements: 881096

one-dimensional elements: 0

two-dimensional elements: 0

integration points per element: 4

degrees of freedom per node: 3

layers per element: 1

distributed facial loads: 0

distributed volumetric loads: 1

concentrated loads: 0

single point constraints: 11748

multiple point constraints: 1

terms in all multiple point constraints: 1

tie constraints: 0

dependent nodes tied by cyclic constraints: 0

dependent nodes in pre-tension constraints: 0

sets: 4

terms in all sets: 3526342

materials: 1

constants per material and temperature: 2

temperature points per material: 3

plastic data points per material: 0

orientations: 0

amplitudes: 5

data points in all amplitudes: 5

print requests: 0

transformations: 0

property cards: 0

STEP 1

Static analysis was selected

Decascading the MPC’s

Determining the structure of the matrix:

Using up to 12 cpu(s) for setting up the structure of the matrix.

number of equations

4431702

number of nonzero lower triangular matrix elements

164843643

Using up to 12 cpu(s) for the stress calculation.

Using up to 12 cpu(s) for the symmetric stiffness/mass contributions.

Not reusing csc.

±------------------------------------------------+

±------------------------------------------------+

Version: 6.0.1

Schedulers:

sequential: Enabled

thread static: Started

thread dynamic: Disabled

PaRSEC: Disabled

StarPU: Disabled

Number of MPI processes: 1

Number of threads per process: 12

Number of GPUs: 0

MPI communication support: Disabled

Distribution level: 2D( 128)

Blocking size (min/max): 1024 / 2048

Matrix type: General

Arithmetic: Float

Format: CSC

N: 4431702

nnz: 334118988

Job failed - no results exist.

Process elapsed time: 94.497 s

When i change the meshsetting to linear element order, the monitor is showing this message:

The numbers below are estimated upper bounds

number of:

nodes: 225597

elements: 881096

one-dimensional elements: 0

two-dimensional elements: 0

integration points per element: 1

degrees of freedom per node: 3

layers per element: 1

distributed facial loads: 0

distributed volumetric loads: 1

concentrated loads: 0

single point constraints: 3312

multiple point constraints: 1

terms in all multiple point constraints: 1

tie constraints: 0

dependent nodes tied by cyclic constraints: 0

dependent nodes in pre-tension constraints: 0

sets: 4

terms in all sets: 3524936

materials: 1

constants per material and temperature: 2

temperature points per material: 3

plastic data points per material: 0

orientations: 0

amplitudes: 5

data points in all amplitudes: 5

print requests: 0

transformations: 0

property cards: 0

STEP 1

Static analysis was selected

Decascading the MPC’s

Determining the structure of the matrix:

Using up to 12 cpu(s) for setting up the structure of the matrix.

number of equations

675135

number of nonzero lower triangular matrix elements

11920437

Using up to 12 cpu(s) for the stress calculation.

Using up to 12 cpu(s) for the symmetric stiffness/mass contributions.

Not reusing csc.

±------------------------------------------------+

±------------------------------------------------+

Version: 6.0.1

Schedulers:

sequential: Enabled

thread static: Started

thread dynamic: Disabled

PaRSEC: Disabled

StarPU: Disabled

Number of MPI processes: 1

Number of threads per process: 12

Number of GPUs: 0

MPI communication support: Disabled

Distribution level: 2D( 128)

Blocking size (min/max): 1024 / 2048

Matrix type: General

Arithmetic: Float

Format: CSC

N: 675135

nnz: 24516009

±------------------------------------------------+

Ordering step :

Ordering method is: Scotch

Time to compute ordering: 0.6300

±------------------------------------------------+

Symbolic factorization step:

Symbol factorization using: Fax Direct

Number of nonzeroes in L structure: 218993472

Fill-in of L: 8.932672

Time to compute symbol matrix: 0.1129

±------------------------------------------------+

Reordering step:

Split level: 0

Stoping criteria: -1

Time for reordering: 0.2282

±------------------------------------------------+

Analyse step:

Number of non-zeroes in blocked L: 437986944

Fill-in: 17.865344

Number of operations in full-rank LU : 498.27 GFlops

Prediction:

Model: AMD 6180 MKL

Time to factorize: 18.8646

Time for analyze: 0.0414

±------------------------------------------------+

Factorization step:

Factorization used: LU

Time to initialize internal csc: 2.7794

Time to initialize coeftab: 0.1206

Time to factorize: 11.1591 (44.65 GFlop/s)

Number of operations: 498.27 GFlops

Number of static pivots: 0

Time to solve: 0.0927

- iteration 1 :

total iteration time 0.0986

error 1.8785e-07

- iteration 2 :

total iteration time 0.101

error 3.0834e-11

- iteration 3 :

total iteration time 0.108

error 1.0337e-14

Time for refinement: 0.3722

- iteration 1 :

total iteration time 0.102

error 7.5287e-17

Time for refinement: 0.1628

## CSC Conversion Time: 0.057964

Init Time: 1.105466

Factorize Time: 14.060342

Solve Time: 0.655722

Clean up Time: 0.000000

Sum: 15.879494

Total PaStiX Time: 15.879494

CCX without PaStiX Time: 11.506344

Share of PaStiX Time: 0.579843

Total Time: 27.385838

Reusability: 0 : 1

Using up to 12 cpu(s) for the stress calculation.

Job finished

Total CalculiX Time: 31.601422

Process elapsed time: 31.727 s