1. Assessing Sensitivity of Vibratory Mode Frequencies to Variation in Geometric Parameters
Vibration in turbine blades must be prevented
Modal analysis can with FEA can determine frequencies
Variation in geometric parameters affects frequency

2. Develop Parametric Blade Model
Create “flexible” turbine blade defined by numerical parameters.
Using Unigraphics (CAD software)
Blade can be altered from normal conditions by changing geometric parameters

3. Sample Design Space Whole set of parameters forms a “design space”
Define normalized parameters with specified
Upper limit
Lower limit
Zero mean
Sample design space using Latin Hypercube Sampling
For N variables, create N combinations of variables
Orthogonal Sample Space
Each set of parameters represents a potential configuration of a real blade

4. Analyze Potential Blade Configurations
Analyze all configurations of real blades using ANSYS
Modal Analysis
Boundary conditions similar to engine operation
Find first 5 mode frequencies
Automate using iSight
Develop Predictive Regression Function
Linear / Non-linear
Least Squares Minimization

5. Summary This project will simulate random variation in turbine blades
The effect of geometry variation on frequency will be quantified
A predictive model will be created to predict frequency based on geometric parameters.

6. Discussion
How many parameters will be required to create a realistic and flexible model?
How many configurations should be analyzed to create dense enough variable space?
What type of regression function should be used?
Linear / non-linear?