Exercise 6

This exercise teaches how to determine if the results from a completed analysis are ready to be assessed.

1. In the Output Bar, click on the Convergence Plot tab.

Note: Because Auto Forced Convection was enabled, the specified number of iterations, 100, were run as flow-only. These were followed by a maximum of 250 Thermal-only iterations.

2. To determine if thermal convergence was attained, check the number of iterations. If it is less than 350 (the sum of the specified flow and maximum thermal iterations) then thermal convergence was attained, and the analysis automatically stopped.

Note: The total number of iterations your analysis completes before stopping may vary slightly from the image above due to slight variations in the different CAD models.

3. To view the Temperature convergence plot, select Temperature from the results menu:

Note: Because Auto Forced Convection was enabled, only the flow solution was solved for during the first part of the analysis. After the flow solution reached the prescribed number of iterations (100), it stopped and only the thermal solution was computed. This is why the temperature curve is flat for the first 100 iterations in the plot above.

4. To determine if the flow solution converged before iteration 100, check for variations in the Temperature prior to iteration 100. Change the End: field to 99 and press the Enter key.

Note: If the temperature had started to change before iteration 100, then we know that the flow solution had reached convergence prior to iteration 100. In this case, that did not happen.

5. To examine the stability of the flow solution, check the pressure and velocity in the Z direction (primary flow direction) by selecting Pressure and then Vz from the results menu.

Conclusion: Pressure fluctuations are minimal and primary flow variations are nearly flat, so flow convergence is adequate for studying trends.

End of Exercise

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