Conventional and Model Based Test analysis GasTurb 13 Conventional and Model Based Test analysis Copyright © GasTurb GmbH

For this tutorial we will use a GasTurb 13 Main Window For this tutorial we will use a 2 Spool Turboshaft. Copyright © GasTurb GmbH

Select the engine model We Need Some Data Select the engine model Open the engine model Copyright © GasTurb GmbH

Test Analysis Input Data Page Switch Test Analysis on and have a look at the Stations Window if you are not sure about where the measurements are taken. Then calculate the Design Point. Copyright © GasTurb GmbH

Test Analysis Result Copyright © GasTurb GmbH These are the measured data given on the test analysis page… These are the iteration variables adjusted to meet the measured data…

Design Point Input Data Page What if W2Rstd is not measured and thus not known? Iterate W2Rstd in such a way that the calculated T5 is equal to the measured T5, for example. Some input quantities, such as compressor and turbine efficiency, pressure ratio and burner exit temperature, are not visible because these data are results in test analysis mode. Note that the data on the Test Analysis Input Page are not the only ones affecting the test analysis. All the other cycle input data, including the secondary air system, must be known for a precise result. Copyright © GasTurb GmbH You can find W2Rstd if you have measured data for T45 or T5. If these values are not known then you may know the HP turbine flow capacity W41Rstd.

Two Test Analysis Methods Conventional Test Analysis Calculates the Cycle Employing the Measured Data Some Knowledge About the Engine is Required Secondary Air System The Test Analysis Runs in Cycle Design Mode The Test Analysis Result is Difficult to Judge: Is Compressor Efficiency Poor Because the Compressor is Damaged or Because it Runs at Aerodynamic Overspeed? Model Based Test Analysis Compares the Measurements with a Model of the Engine A Full Thermodynamic Model is the Basis The Test Analysis Runs in Off-Design Mode Factors to the Component Performance are Found Which Make the Model Agree With the Measured Data The Test Analysis Result is the Deviation Between the Model and the Engine The Result for Compressor Efficiency is Independent of the Operating Point: Better or Worse than Expected What we have done up to now was a Conventional Test Analysis. Now we go for the Model Based Analysis, also called Analysis by Synthesis (AnSyn) Copyright © GasTurb GmbH

The file opening menu will appear automatically, read the file GasTurb 13 Main Window The file opening menu will appear automatically, read the file Demo_mgtf.cgm After reading the data, the cycle design point will be calculated in the background and then the Off-Design Input Window opens. Now we will use a Geared Mixed Turbofan In calculation mode Off Design With Standard Maps Copyright © GasTurb GmbH

Off Design Input Window Select Test Analysis and switch to the Test Analysis View Copyright © GasTurb GmbH

Test Data Input Copyright © GasTurb GmbH Click here to run the test analysis Example test data are stored in the file. Copyright © GasTurb GmbH

Click here to see the whole cycle AnSyn Result Click here to see the whole cycle A value of 1 (or 0K respectively) for the AnSyn Factors in this column means perfect line-up of the measurement with the model. The HPC Efficiency Factor is around 0.982, that means the HPC performs worse than expected. Copyright © GasTurb GmbH

AnSyn Result Copyright © GasTurb GmbH Remember: the overall compression pressure ratio P3/P2 is 35.6737 Copyright © GasTurb GmbH These are the measured data given on the test data page.

Correction to Nominal Conditions Change Delta T from ISA to 0 Click here to run the ISA Correction Now run the model - with the AnSyn Factors applied - at the same corrected spool speed as tested. This yields pressure ratios that are very close to those during the test. Copyright © GasTurb GmbH

Data Corrected to Nominal Conditions Now the overall compression pressure ratio P3/P2 is 35,67347 Copyright © GasTurb GmbH

Sensitivity to Measurement Errors Sensitivity to Measurement Errors can be calculated automatically Copyright © GasTurb GmbH

Sensitivity to Measurement Errors Need Explanations? Copyright © GasTurb GmbH

Flexibility of AnSyn Copyright © GasTurb GmbH What if no measured mass flow W2 is available? Here you can choose the Core Flow Analysis Method. Define an Iteration Core Flow Analysis Methods Iterate Bypass Ratio (Core Flow) in such a way that one of the following conditions is fulfilled: W41Rstd = given W41Rstd (HP Turbine Capacity) W45Rstd = given W45Rstd (LP Turbine Capacity) T45 = Measured T45 T5 = Measured T5 Copyright © GasTurb GmbH

Defining an Iteration Copyright © GasTurb GmbH Assume that the fan model is correct, for example. That means the Fan Flow Factor is equal to 1 Copyright © GasTurb GmbH

This is now the start value for the iteration. Calculate… This is now the start value for the iteration. Copyright © GasTurb GmbH

Mass Flow W2 Found by Iteration Copyright © GasTurb GmbH

Conventional and Model Based Test Analysis Tutorial Flexibility of AnSyn What if there are additional measured data to be considered ? … and use optionally an iteration to bring the measurement in line with the Composed Values. Employ these placeholders for input of the data… Copyright © GasTurb GmbH This slide ends the Conventional and Model Based Test Analysis Tutorial