CONVENTIONAL AND MODEL BASED TEST ANALYSIS GasTurb 12 Copyright © GasTurb GmbH

GasTurb 12 Main Window For this tutorial we will use a 2 Spool Turboshaft. For this tutorial we will use a 2 Spool Turboshaft. Copyright © GasTurb GmbH

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

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. 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 These are the measured data given on the test analysis page… Copyright © GasTurb GmbH These are the measured data given on the test analysis page…

Design Point Input Data Page 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 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. What if W2Rstd is not measured and thus not known? 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. Iterate W2Rstd in such a way that the calculated T5 is equal to the measured T5, for example.

Two Test Analysis Methods Copyright © GasTurb GmbH 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 Worth 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)

GasTurb 12 Main Window Now we will use a Geared Mixed Turbofan In calculation mode Off Design With Standard Maps Now we will use a Geared Mixed Turbofan In calculation mode Off Design With Standard Maps Copyright © GasTurb GmbH 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. 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.

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

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

AnSys Result Copyright © GasTurb GmbH 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 1.09, that means the HPC performs better than expected. Click here to see the whole cycle

AnSys Result Copyright © GasTurb GmbH This are the measured data given on the test data page. Remember: the overall compression pressure ratio P3/P2 is 35.67

Correction to Nominal Conditions Copyright © GasTurb GmbH 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. 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. Click here to run the ISA Correction Change Delta T from ISA to 0

Data Corrected to Nominal Conditions Copyright © GasTurb GmbH Remember: the overall compression pressure ratio P3/P2 in the test was 35.67

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

Sensitivity to Measurement Errors Copyright © GasTurb GmbH Need Explanations?

Flexibility of AnSyn Copyright © GasTurb GmbH Here you can choose the Core Flow Analysis Method. 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 What if no measured mass flow W2 is available? Define an Iteration

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

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

Mass Flow W2 Found by Iteration Copyright © GasTurb GmbH Found by Iteration

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