1. Design of a Nulling Yaw Probe for a Gas Turbine Engine Test Rig
ME 462: Capstone Design
Group Members: Steve Collins
Bill Donelson
Allison Heying
Brent Miller
Faculty Advisor: Dr. Jie Chen
Corporate Sponsors: Rolls-Royce
Dr. Kurt F. Weber
Bruce Crook
Presented May 4, 2006

2. Design Problem
Design an apparatus to self-null a yaw probe in a gas turbine engine test rig with the following customer requirements:
Radial motion of 2” in increments of 0.1”
Circumferential motion around the annulus
Yaw motion over 180° with accuracy of 0.5°

3. Design Functions
Determine the flow angle utilizing fully automated controls, i.e. self-null the probe
Measure the total pressure
Collect data over the entire flow annulus
Mount downstream of the inner ring

4. Project Justification
Validation testing of fluid flow over combustor saddles
Correlate CFD models of total pressure fluctuations which can cause blade forcing
High altitude engine performance prediction for T-56 Engine

5. Project Management Task List: Deliverables Objectives
Required Personnel
Required Time
Gantt Chart

6. Self-Nulling Yaw Probeφ
Nulled when P2 = P3
φ = Yaw Angle
P1 = Total Pressure

7. Automated Self-Nulling
L.C. Smith Controller:
Executes Automated Self-Nulling
Displays Flow Angle

8. Self-Nulling Process
Video

9. Current Design Capabilities: Radial motion Circumferential motion
No flow angle
measurements

10. New Design Capabilities:
Integration of a stepper motor to facilitate measurement of yaw angle
Stepper motor provides 0.25° increments
Motor bracket provides housing for gearing and support for the pressure probe
Potentiometer provides feedback to L.C. Smith Controller

11. New Design (cont.) Capabilities Continued:
New apparatus attaches to existing rack via motor support
Dovetail slides constrain motor along radial path

12. ANSYS Analysis Motor support assembly in vertical position
Displacement
Stress
Max stress = 1,040 psi
Yield stress = 40,611 psi
Max = in

13. ANSYS Analysis Cont. Motor support assembly in horizontal position
Displacement
Stress
Max = in
Max stress = 206 psi
Yield stress = 40,611 psi

14. Fulfillment of Requirements
Yaw motion:
Target : 180° with 0.5° accuracy
Final design : 180° with 0.25° accuracy
Radial motion:
Target : 2 inches of motion
Final design : 2 inches of motion
All other targets:
Met since aspects of benchmark that fulfilled requirements were kept for final design

15. Conclusions All engineering specifications were either met or exceeded
Working prototype with a cost of $
Compact design makes it compatible with other engine test rigs

16. Recommendations New Design Old Design
Widen the cut out in the inner ring a ¼ inch
Relocate the static pressure tap tube
4 tapped holes to attach the dovetail slides
Determine the added resistance to the motor wiring to make it
compatible with the L.C. Smith

17. Questions Special Thanks To: Dr. Kurt F. Weber Bruce Crook
Rolls-Royce Corporation
Dr. Jie Chen