# Cycle Design Parametric Study

## Presentation on theme: "Cycle Design Parametric Study"— Presentation transcript:

Cycle Design Parametric Study
GasTurb 12 – Tutorial 2 Cycle Design Parametric Study Copyright © Joachim Kurzke

For this tutorial we will consider a 2 Spool Turbofan.
GasTurb 12 Main Window For this tutorial we will consider a 2 Spool Turbofan. Copyright © Joachim Kurzke

First we run a single cycle
Input Data Page First we run a single cycle Copyright © Joachim Kurzke

This is a cycle for a business jet engine. Cruise flight condition is Mach 0.8. The overall pressure ratio is rather low (P3/P2=17.33), burner exit temperature is 1450K and the bypass ratio is 6.

Turbofan Station Designation
Copyright © Joachim Kurzke These are the locations of the thermodynamic stations and the secondary air system paths

Now we go for a Parametric study.

Click here to run all cases This is the HP Compressor Pressure Ratio of the Single Cycle calculated before this parametric study. Choose a property from the list, double click or drag it to the parameter page on the right. You can also click the arrow for moving a parameter from left to right. We employ HP Compressor Pressure Ratio as the only parameter for now. Copyright © Joachim Kurzke

Graphical Output Picture Definition
The result of a parametric study is presented graphically. Sp. Fuel Consumption and Net Thrust are the default plot parameters. To employ Overall Pressure Ratio P3/P2 as x-axis, drag it to the box below the schematic picture. Then click Draw y=f(x) Copyright © Joachim Kurzke

Single Parameter Plot With a Single Y-Axis
This black square marks the Cycle calculated before beginning the Parametric study Copyright © Joachim Kurzke We go back to the previous window and select a new view (New Picture) of the data created in the Parametric Study

Single Parameter A Plot With Several Y-Axes
Select the number of y-axes first! Copyright © Joachim Kurzke We will employ several y-axes Drag four parameters to the respective y-axis boxes. Then click Draw y=f(x)

On each y-axis there is a different symbol. This line belongs to the LPT Pressure Ratio axis – the symbols on the line and on the axis are the same. Close this window to go for a new Parametric study. Copyright © Joachim Kurzke

Parameter Selection Adding a Second Parameter
Click this tab for specifying the second parameter Use these numbers Click here to run all cases This is the Burner Exit Temperature of the cycle calculated before this Parametric study. Copyright © Joachim Kurzke We employ Burner Exit Temperature as the second parameter

The Default Plot No Contour Lines
This little black square marks the cycle calculated before beginning the Parametric study Next have a look at all the data from a specific parameter combination. Click Detailed Output Copyright © Joachim Kurzke

Getting the Detailed Output for any Parameter Combination
Now we will add more information to the picture. Click New Picture Copyright © Joachim Kurzke SELECT Double click (in GasTurb) to select T4=1425 and HPC Pressure Ratio = 9

Contour Parameter Selection
An option: Click to sort the property names alphabetically Copyright © Joachim Kurzke

Click to apply the new settings
Editing Contours Edit the numbers: Lowest Contour Value = 0.435 Step Size = 0.005 Click to apply the new settings Copyright © Joachim Kurzke

Let us add now a design limit for T45 of 1200 K
The Customized Plot Let us add now a design limit for T45 of 1200 K to the carpet. Copyright © Joachim Kurzke

Showing Design Limits Example: Add a Boundary for T45>1200K

Specific Fuel Consumption (SFC) as a Function of HPT Pressure Ratio
The disadvantage of this plot is that there is no information about HPT Pressure Ratio anymore. To correct for that we add contour lines for HPT Pressure Ratio. We go for another New Picture Sometimes the lines are overlapping and the plot is difficult to read Changing the Layout resolves this problem Copyright © Joachim Kurzke

Closing this window brings us back to the cycle design input window
Specific Fuel Consumption (SFC) as a Function of Ideal Jet Velocity Ratio V18/V8 For each HP Compressor Pressure Ratio the best SFC is achieved if the Ideal Jet Velocity Ratio V18/V8 is approximately 0.8. This relation between the bypass nozzle velocity V18 and the core nozzle velocity V8 can be achieved by choosing the right Outer Fan Pressure Ratio. In the next parametric study we will iterate Outer Fan Pressure Ratio in such a way that the Ideal Jet Velocity Ratio V18/V8 is equal to 0.8. Thus all the cycles are optimized for Specific Fuel Consumption SFC . Copyright © Joachim Kurzke Closing this window brings us back to the cycle design input window

How to define an iteration is shown in the
Define the Iteration How to define an iteration is shown in the Single Cycle Tutorial Copyright © Joachim Kurzke

Re-Run the Parametric Study

No Change in this Window

Outer Fan Pressure Ratio is Optimized

GasTurb Copy to Clipboard, Pasted into Power Point and Re-Sized

De-Activating the Iteration
Click to de-activate the iteration Now run the Parametric study again Copyright © Joachim Kurzke

Outer Fan Pressure Ratio = 1.8 Iteration is De-Activated
Adjust the scales to make the picture comparable to the picture with the optimized Outer Fan Pressure Ratio. Copyright © Joachim Kurzke

Outer Fan Pressure Ratio = 1.8
Repeat clicking this button until no parameter values are shown Copyright © Joachim Kurzke

Outer Fan Pressure Ratio = 1.8

The Overlay on the Clipboard