Project EML 5526 Finite Element Analysis and Applications

Apply FEA software to solve the problems listed below. In the final report, you must have the

following for each problem:

a) You must clearly describe the real physical system(s) and any simplifying assumptions.

b) Describe and justify the FEA model you are using. Your description of the model should

include the type of element you used, the boundary conditions that you apply, material

properties you used, as well as a list of assumptions involved in the model. Attach

pictures/figures as needed to explain the model and the results.

c) Compare the solution obtained by FEA software using different models / elements. Study

how your answer changes with mesh density and plot a convergence curve for the

secondary variable (stress/strain/heat flux).

d) Discuss how you have validated your results such as intuitive reasoning, analytical or

approximate solutions or comparing solutions from different elements or models.

Problem 1

The figure below shows the cross-section of a heat exchanger with built in pipes designed to carry

fluid at different temperatures. Assume there are numerous such pipes carrying fluid at 30 and

100oC such that each pipe at high temperature has cold pipes on either side. Assume that the

diameter of the pipes are 0.2m and that they are evenly spaced with distance between the centers

0.4m.

Due to the high velocity of the flow through pipes the temperature at the inside pipe walls can be

assumed to be a constant 30oC for the cold pipes and 100oC for the hot pipes. The thermal

conductivity of the material of the heat exchanger k = 0.3 W/m oC. Outside the concrete pipe, the

surrounding air temperature is 25oC and the natural convection coefficient h = 0.2 W/m2 oC.

Describe the model you would use (by exploiting the periodicity and symmetry of the problem) to

find the temperature distribution in the cross-section and determine the maximum temperature on

0.5m

1m

30oC 100 o C

2

the outside surface of the pipe. Explain your assumptions. Use both a 2D and 3D model for

comparison.

Problem 2)

The frame shown in figure has a square cross section of 20x20mm2. The load P equal to a

magnitude of 100N is applied at the center of the frame from both sides to squeeze it inwards.

The Young’s modulus of the material is assumed to be 200 GPa and Poisson’ ratio equal to 0.3.

a) What is the appropriate model for this problem? (Make use of symmetry)

b) Compare solution with and without using symmetry.

c) Compare solutions using 2D versus 3D model for this problem. How close are the two

solutions?