In the previous step, we solved the steady state flow distribution. In this step, we will solve the time-varying temperature distribution.

Click Solve from the Setup tab:

Click the Physics tab.

Flow = Off

Heat Transfer = On

Click the Control tab.

Solution Mode = Transient

Time Step Size = 5

Inner Iterations = 2

Results (under Save Intervals) = 2

Continue From = s100

Time Steps to Run = 16

In the first stage of this simulation, Intelligent Solution Control was enabled to control the convergence progression of the steady state stage of the analysis. In the transient stage, we need to disable Intelligent Solution Control:

Click Solution control.

On the Solution Controls dialog, uncheck Enable, and click OK.

Click Solve to start the analysis.

These settings cause the solution to vary with time.

The time step is 5 seconds, and we are running 16 time steps, for a total of 80 seconds. This solves two complete cycles of the transient inlet temperature (period = 40 seconds).

Setting the Results Save Intervals to 2 saves every other time step (every 10 seconds).

The number of inner iterations per time step is reduced to 2 because flow-only heat transfer is linear, and does not require the default of 10 inner iterations.

For more about running transient analyses

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