Skip to content

Latest commit

 

History

History
 
 

thermo1d

README.md

Steady State Heat Conduction

Tested with CGX 2.20 / CCX 2.20

  • Steady state thermal analysis
  • Prescribed volumentric heat production, isothermal boundary and prescribed flux density
  • Comparison of averaged and non-averaged nodal solution
  • Comparison of 3D solid model and 2D plane model

Issue

Due to wrong surface definition by CGX (for the given topology, the edge at x=L should be S1 of element 1 and not S4 as written in the xL.sur file.

the result of the 2D model isn't correct. On the right end you see a skewness in the flux distribution (T should not depend on y). Also, the path plot shows that at x = 3 m the value of q isn't correct (should be 0.5).

File Contents
run.fbd CGX script for 3D model
solve.inp CCX input for 3D model
solve_sep.inp CCX input for non-averaged solution (3D-model)
run2d.fbd CGX script for plane model
solve2d.inp CCX input for plane model
solve2d_sep.inp CCX input for non-averaged solution
path.gnu Gnuplot control file for the combined path plot (3D)
path2d.gnu Gnuplot control file for the combined path plot (2D)
test.py Python script to run the simulation

The model represents a uniform bar for demonstration of 1D steady state heat conduction

Parameter Value Meaning
lx 3 x dimension in m
ly 1 y dimension in m
lz 1 z dimension in m

The parameters are defined in run.fbd and run2d.fbd

3D Solid Model

The geometry consists of a hexaeder. It is meshed with 3 C3D8 elements.

> cgx -b run.fbd

The script does the following

  • Create geometry and mesh
  • Write set definitions
  • Produce a mesh plot
  • Run the averaged solution
  • Create q contour plot and path plot
  • Call separate.py and run the non-averaged solution
  • Create q contour plot and path plot
  • Create the combined plot

2D Plane Model

The geometry consists of a quadrilateral in the xy plane. It is meshed with 3 CPS4 plane stress elements, which are expanded into 3 C3D8 elements.

> cgx -b run2d.fbd

The script does the following

  • Create geometry and mesh
  • Write set definitions
  • Produce a mesh plot
  • Run the averaged solution
  • Create q contour plot and path plot
  • Call separate.py and run the non-averaged solution
  • Create q contour plot and path plot
  • Create the combined plot