kobros
Automotive
- Feb 8, 2007
- 1
Hallo,
please, can anybody give me an advice in solving a basic linear steady state thermal convection problem using 4-node HLINK element?
Using HSTAR Skyline solver the analysis ends with error message : " zero stiffnes matrix equation : 11"
Others HSTAR solvers end with something similar.
R_CHECK command ends correctly with no errors.
There is no relevant information in .tem file. No thermal results and except the information of used solver it is a blank file.
Probably, I have got problems in setting HLINK element and its boundary conditions.
I defined 2 Surfaces. Surface 2 is of TZM/molybdenum. I consider heat produced in Surface 2 (QEL,9,2636.758411431,16,1) and convection boundary condition(CEL,12,72491,323.15,2,16,4,0). Surface 2 is meshed with PLANE2D element.
Surface 1 is flowing Helium.Surface 1 is meshed with HLINK element. For helium I declare following boundary conditions: Nodal pressure (NPRND,1,7000000,15,1),source of temperature on Curve 2 (NTCR,2,873.15,2,1) and Hydraulic flow (HFND,1,0.005,15,1).
I tried some modifications with nodal pressure and hydraulic flow - for example not defining nodal pressure at all nodes in surface 1, but only on Curve 1,changing values, etc. .There are no differences in results of thermal analysis for these modifications - just the error message and almost blank .tem file
Thank you.
SF4CORD,1,0,0,0,0.001,0,0,0.001,0.002,0,0,0.002,0
SF4CORD,2,0.001,0,0,0.01,0,0,0.01,0.002,0,0.001,0.002,0
ACTSET,MP,1
MPROP,1,HC,1000
MPROP,1,KX,0.2
MPROP,1,C,5180
MPROP,1,DENS,4.2
MPROP,1,VISC,0.00004
ACTSET,MP,2
MPROP,2,DENS,10220
MPROP,2,KX,80
MPROP,2,C,300
ACTSET,EG,1
ACTSET,RC,1
ACTSET,MP,1
EGROUP,1,HLINK,1,0,0,0,0,0,0,0
RCONST,1,1,1,6,0.002,0,0,0.023,0.8,0.4
M_SF,1,1,1,4,4,2,1,1
ACTSET,EG,2
ACTSET,RC,2
ACTSET,MP,2
EGROUP,2,PLANE2D,0,1,1,0,0,0,0,0
RCONST,2,2,1,2,0,0
M_SF,2,2,1,4,4,2,1,1
NMERGE,1,500,1,0.0001,0,1,0
NCOMPRESS,1,500
QEL,9,2636.758411431,16,1
CEL,12,72491,323.15,2,16,4,0
NPRND,1,7000000,15,1
NTCR,2,873.15,2,1
HFND,1,0.005,15,1
A_THERMAL,S,0.001,1,1,20,0,1,1E+008,0,1,0
please, can anybody give me an advice in solving a basic linear steady state thermal convection problem using 4-node HLINK element?
Using HSTAR Skyline solver the analysis ends with error message : " zero stiffnes matrix equation : 11"
Others HSTAR solvers end with something similar.
R_CHECK command ends correctly with no errors.
There is no relevant information in .tem file. No thermal results and except the information of used solver it is a blank file.
Probably, I have got problems in setting HLINK element and its boundary conditions.
I defined 2 Surfaces. Surface 2 is of TZM/molybdenum. I consider heat produced in Surface 2 (QEL,9,2636.758411431,16,1) and convection boundary condition(CEL,12,72491,323.15,2,16,4,0). Surface 2 is meshed with PLANE2D element.
Surface 1 is flowing Helium.Surface 1 is meshed with HLINK element. For helium I declare following boundary conditions: Nodal pressure (NPRND,1,7000000,15,1),source of temperature on Curve 2 (NTCR,2,873.15,2,1) and Hydraulic flow (HFND,1,0.005,15,1).
I tried some modifications with nodal pressure and hydraulic flow - for example not defining nodal pressure at all nodes in surface 1, but only on Curve 1,changing values, etc. .There are no differences in results of thermal analysis for these modifications - just the error message and almost blank .tem file
Thank you.
SF4CORD,1,0,0,0,0.001,0,0,0.001,0.002,0,0,0.002,0
SF4CORD,2,0.001,0,0,0.01,0,0,0.01,0.002,0,0.001,0.002,0
ACTSET,MP,1
MPROP,1,HC,1000
MPROP,1,KX,0.2
MPROP,1,C,5180
MPROP,1,DENS,4.2
MPROP,1,VISC,0.00004
ACTSET,MP,2
MPROP,2,DENS,10220
MPROP,2,KX,80
MPROP,2,C,300
ACTSET,EG,1
ACTSET,RC,1
ACTSET,MP,1
EGROUP,1,HLINK,1,0,0,0,0,0,0,0
RCONST,1,1,1,6,0.002,0,0,0.023,0.8,0.4
M_SF,1,1,1,4,4,2,1,1
ACTSET,EG,2
ACTSET,RC,2
ACTSET,MP,2
EGROUP,2,PLANE2D,0,1,1,0,0,0,0,0
RCONST,2,2,1,2,0,0
M_SF,2,2,1,4,4,2,1,1
NMERGE,1,500,1,0.0001,0,1,0
NCOMPRESS,1,500
QEL,9,2636.758411431,16,1
CEL,12,72491,323.15,2,16,4,0
NPRND,1,7000000,15,1
NTCR,2,873.15,2,1
HFND,1,0.005,15,1
A_THERMAL,S,0.001,1,1,20,0,1,1E+008,0,1,0
