Copyright © Joachim Kurzke
Introducing GasTurb 11
Control System Simulation
Copyright © Joachim Kurzke
GasTurb 11 Main Window
Select the engine architecture from the Configuration List.
Alternatively you could select it from the Configuration Tree.
Copyright © Joachim Kurzke
The Engine Configuration List
Select the Turbojet…
... use the Scope Performance
with the Calculation Mode Off-Design
and choose for the Maps Standard
The file opening menu will appear automatically,
read the file Demo_jet.cyc
After reading the data, the cycle design point will be
calculated in the background before the Off-Design Input
Window opens.
Copyright © Joachim Kurzke
Off-Design Input Window
The control system protects the engine by limiting temperatures, pressures, spool speeds etc.
Click the Limiters tab.
Copyright © Joachim Kurzke
Max Limits
You can set switch on several limiters simultaneously. The
limiter which restricts the engine most will fix the operating point.
Enter numbers here
Activate the selected limiters
Click the Max Limiter option
Copyright © Joachim Kurzke
Solution for Three Active Limiters
Active Limiter
T3,max=650K
Nrel,max=101%
The Turb Exit Temperature T5 limiter is active, neither the Spool Speed NH limit nor the
Compressor Exit Temperature T3 limit is violated
Copyright © Joachim Kurzke
Fuel Flow and Thrust as Pseudo Limiters
You may want to run the engine to a given thrust.
Enter the desired thrust
Activate the limiter here
Copyright © Joachim Kurzke
The Cycle for 25kN Thrust
Copyright © Joachim Kurzke
Copyright © Joachim Kurzke
HPC Spool Speed ZXNwith Activated Limiters
If any limiter is active, then the input for ZXN given (1) or ZT4 given (2)
is automatically set to 1.
The HP Spool Speed ZXN is no longer seen on this page
Copyright © Joachim Kurzke
If you want to consider a limiter which is not on the Limiters page,
then define a composed value.
While a limiter is active, HP Spool Speed ZXN is an iteration variable
Copyright © Joachim Kurzke
Any Composed Value can be employed as Limiter.
Introduce as a P5Limiter the ratio of P5/P2, for example.
Close this window and go to the Limiters page
Copyright © Joachim Kurzke
Click to see the composed value
Copyright © Joachim Kurzke
The P5/P2 Limiter is Active
Copyright © Joachim Kurzke
De-select the P5Limiter
Besides single valued limiters you can also employ
Control Schedules
Copyright © Joachim Kurzke
Defining a Control Schedule
1 Select the parameter to be controlled
2 Select the parameter from which the controlled parameter
depends
3 Enter numbers
Plot the schedule
Click to activate the schedule
Keep in mind:At T2=300K T5 = 1110K.
Copyright © Joachim Kurzke
T5 Controlled to a Schedule
Copyright © Joachim Kurzke
Changing Ambient Temperature
Delta T from ISA = 11.85K yields at sea level static conditions
T2=300K
Copyright © Joachim Kurzke
T5 Follows the Schedule
Remember:T2 = 300K yields as
scheduled T5 = 1110K.
Copyright © Joachim Kurzke
T5 Controlled to a Schedule
Next we introduce a nozzle area schedule.
Copyright © Joachim Kurzke
Nozzle Area Schedule
We will use this Delta Nozzle Area schedule for increasing the surge margin of the compressor at
low corrected speed.
Before continuing, select Turb Exit Temperature T5
from the parameter list and click the bulb to make this limiter
schedule inactive.
Copyright © Joachim Kurzke
Run Two Operating Lines
To demonstrate the effect of the schedule, we run two operating lines:
- one with scheduled nozzle area- the other with nominal A8
Copyright © Joachim Kurzke
After the 1st Operating Line is Completed
Choose 16 for the Number of Pointsbefore running the 1st operating line
Copyright © Joachim Kurzke
Next Operating Line
Nozzle Area follows a schedule.
1 Click and de-activate the nozzle
area schedule
2 Add some descriptive text
3 Run one more operating line. When asked
Another operating line ? Click No
Copyright © Joachim Kurzke
Effect of the Delta A8 Schedule on the Compressor Operating Line
Nozzle Area follows the schedule.
This slide ends the Control System
Simulation Tutorial
Increased surge margin because the nozzle
opens at low corrected spool speeds
Top Related