Department of process engineering U218 Numerical Analysis of Equipment (tutorials)

NOTES from LECTURES 2002

FILES for seminars with COSMOS/M

• C0 -Operating system (UNIX,LINUX)

  UNIX	(Linux,vi-editor, screen grabing), file NAZLOGIN.DOC

• C1 -Structural analysis (trusses and beams)

  N1-pipe.GEO	Pipe-network (COSMOS) Elements PIPE, LINEAR, STATIC
  N1-pipe.f	fortran program for postprocessing of N1-pipe.GEO
  N2-truss.GEO	Elements TRUSS2D, LINEAR, STATIC analysis
  N2-trusb.GEO	LINEAR, BUCKLING (the same as N2-truss.geo, only R_BUCKLING replaces R_STATiC)
  N2-trusnel.GEO	Large deformation (commands defining time course of loading: CURDEF, TIME)

  
  

• C2 -Structural analysis (shells, membranes and rings)

  N3-light.GEO	-gas lighter (Elements SHELL3, LINEAR, STATIC)
  N4-stf.GEO	-Elements SHELLAX,TRIANG,FLOW2D
  (this file contains in fact solution of 3 problems: rotationally symmetric pressure vessel, a flange and flow of liquid in a channel) The file N4-stf.geo can be executed by Cosmos, however it is better to separate it to the three parts N4-shell.GEO -elements SHELLAX (e.g. Deware vessel) N4-trian.GEO -elements TRIANG (representing rings of triangular cross-section) N4-flow.GEO -elements FLOW2D (2D flow of liquid in a curved channel) Procedure: Transfer the files N4-shell.geo,... to your home directory using e.g. Netscape. Start COSMOS and open a problem, e.g. N4. Then write command FILE and N4-shell.geo. All lines in the file will be interpreted calculation performed and you can check results (plot stresses, and so on - use menu RESULTS in Cosmos). Even then write FILE again, specify N4-triang.geo. This session file ensures deleting existing SHELLAX elements first, and then generates a new mesh from elements TRIANG and static analysis is performed. Look at results and repeat the same procedure for FLOW2D elements.

  
  

• C3 -How to write your own FEM program

  N5-truss.f 2D-trusses (F77 for Silicon Graphics) N5-truss.dat example of input data for N5-truss.f N5-truss.out example of output data from N5-truss.f

  These files represent a simple FEM program written in Fortran - calculation of displacements of joints of trusses, loaded by prescribed forces. Maximum number of trusses is 50. The source file can be compiled and assembled using command: f77 N5-truss.f -o N5 , where the last parameter N5 is the name of executable file (you can specify any other name of course).
  
  

  C4 -Heat and analogy (Laplace equation)

  N6-temp.GEO -temperature field 2D (Cosmos). Script N6-temp.geo defines several triangular elements (TRIANG) directly using ND and EL commands, without geometrical model and solves stationary temperature field.
  N6-temp.FOR -temperature field (fortran). Simple linear basis functions in triangular elements. Assembly of full matrix. Gauss-Jordan method of solution (see Numerical Recipes). Program is without graphics and therefore is fully portable. N6-temp.DAT -temperature field (data for fortran N6-temp.FOR, describing the same problem as N6-tem.GEO)
  N7-ohmic.GEO -elliptical vessel, cylindrical electrodes at focus (direct ohmic heating). Module THERMAL is used for solution of electrical potential. Example of meshing in a multiply connected region (MARG). Triangular elements TRIANG, steady state, constant properties (electrical conductivity=thermal conductivity)
  N7-ohmic.FOR -fortran program for postprocessing of temperature field (e.g. N7-ohmic.GEO) (power integration). The program read output file N7-OHMIC.TEM and calculates gradients of electric field in all elements, and subsequently dissipated pover in elements. N7-ohmic.TEM -vysledky N7-ohmic.GEO (Cosmos) a vstupni data pro N7-ohmic.for
  Electric potential U(x,y) 6.10.2001 Finite differences. Overrelaxation by Gauss-Seidel. electric.f fortran for SGI electric.c C for SGI electric.for PWS fortran (graphics MINIPF.LIB).
  electric.SES -the same example as the Fortran program ELECTRIC.f (elektrolyzer) written for COSMOS. Parametric meshing of triangular elements.
  FEMIN.ZIP Temperature field - program written by using Fortran PowerStation for Windows using Microsoft graphics. This program looks like COSMOS/M, but only few basic operations are defined, eg. entities PT,CR,SF (points, curves, surfaces), ND,EL (nodes and elements). Parametric generator of mesh can be used for generation of triangular (3,4,6,7 nodes) or qudrilateral (4,5,8,9 nodes) elements. Frontal method is used for assembly and solution of system of equations. Maximum front width 200, maximum number of nodes 1000. Script language enables to use expressions with variables (predefined variables A,B,.,Z,ND,NE,NPT,NCR,NSF,XND(*),...) and functions. Mouse is used for definiton and picking points or nodes. Available commands: NEWPROB,FILE,CLS,SCALE,ZOOMIN,ZOOMOUT, PT,CR3PT,SF4PT,SF8PT,CIRCLE,CURDEF,FUNDEF, PTPLOT,CRPLOT,SFPLOT,NDPLOT,NFPLOT,EPLOT, PTLIST..., NIDENT..., EGROUP,MPROP,RCONST, MSF,NFCR,THERMAL,CREEP,SHELLAX,GRAPH,GRAFUN,... 25.11.2001

  
  

  C5 -Computer Fluid Dynamics

  Theory of pressure thermal forming (flow of expanding material in a mold) wafflcz.doc [800KB] (in czech) wafflen.doc [500KB] (in english) N8-waff.FOR-fortransky program expanze oplatek [i pro SGI] N8-waff.DAT-data pro fortransky program expanze oplatek
  CFD-introduction cfdcz.doc (penalty method for NS equations)
  Nazflow.GEO -Laminar flow (ohmic heater nonisothermal, flow asymmetry)

REFERENCES

Zadání problému 1:

1. Překopírujte soubor z databáze NAZ7.SES na NAZ71.GEO použitím Unixovského příkazu cp.
2. Smažte celou databázi původního problému NAZ7 (tj. všechny soubory NAZ7.*).
3. Použijte editor VI na vložení následující řádku někam na začátek souboru NAZ71.GEO
   PARASSIGN,PRESS,REAL,1E7 (přiřazovací příkaz, PRESS=1E7)
   a modifikujte příkaz pro definici parametrů elementů
   RCONST,1,1,1,3,0.133,0.0055,PRESS
   
   Parametrické programování se používá především při opakovaném provádění úlohy, např. pro analýzu potrubní sítě při různých tlacích PRES=1E7 a 1E8:
   PRINT_OPS 1 0 0 1 0 0 1 0 0 1 tento příkaz je potřebný k tomu, aby nové výsledky nepřemazávaly ty staré (z předchozího cyklu)
   Následující příkazy je třeba umístit těsně před začátek výpočtu:
   #LOOP END 2 začátek příkazu cyklu (2 cykly končící návěštím END)
   #PARASSIGN,PRESS,REAL,PRESS+9E7 (přiřazovací příkaz PRESS=PRESS+9E7)
   R_STATIC spouštění výpoču není automaticky zařazováno do SESSION filu, ale lze je tam "ručně" dopsat
   #LABEL END konec příkazu cyklu
   EDIT PRESS1.OUT výsledkový soubor je možné prohlížet přímo v COSMOSu editorem VI.
4. Spusťte program COSMOS s názvem úlohy NAZ71.
   >FILE: NAZ71.GEO; načtení a interpretace modifikované session filu
   >R_STATIC spuštění statické analýzy
   >EXIT
5. Použitím FTP přeneste výsledkový soubor na Váš lokální počítač.

Problém 2.

Problém 3.

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