Quick start basics - Adapting a model .

It is often required to analyze the effects of small changes in the engine characteristics relative to a baseline engine.

For example, to analyze the effect of a lower compressor isentropic efficiency on the TJET model transient performance. Effectively another engine design is obtained. To model this modified engine do the following:

1. Click in the Project tree panel on the "TJET_Config" node to load the original configuration. Now insert a new configuration and name it "Alternate engine"

2. Double-click the compressor component in the model panel and change the design efficiency from 0.825 to 0.75.

3. Altering the design should be noted on the model notes panel to state any deviations from the base/reference model so that other people understand the model structure. Enter a not similar to: "This model has a lowered compressor efficiency due to using a more conservative compressor design. The design efficiency has changed from 0.825 to 0.75."

4.	Create a child transient case and specify a transient fuel flow input function in the model as specified in "Running transient simulations".

5.	Click the 'append break button' of the table window toolbar to append a break line.

The graph window will automatically interpret the break lines as curve separators.

6.	Run the simulation.

The transient table now contains two transient response calculations, separated by a break row (first transient dataset was created in Running transient simulations).

The graph will now display two datasets, so that the performance of the alternate engine can be graphically compared to the initial design.

Note: The transient results calculated here do not represent typical transient gas turbine performance due to the use of a Manual Fuel Flow Control component. For actual transient performance analysis a GSP generic or dedicated fuel control system component needs to be used instead.