Heat Transfer Analyses of Internal Cooling Passages of Turbine Blades and Nozzles

Transcription

1 Heat Transfer Analyses of Internal Cooling Passages of Turbine Blades and Nozzles Matthew Mihelish Heat Transfer Mentor: Luzeng Zhang Manager: Hee-Koo Moon Supervisor: John Mason

2 Agenda Personal Background Turbine Blade Background Modified Blades Experimental Setup Post Processing Conduction Analysis Transient Convection and Conduction Program Results Turbine Nozzle Background Experimental Setup Results Development Testing and Turbine Assembly (Dept. 133)

3 Personal Background Education B.S.M.E. University of Idaho, 2009 M.S.M.E University of North Dakota, Fall 2011 Thesis: Heat Transfer, Aerodynamics, and Losses at Low Reynolds Numbers in High Speed Flows Past Internship NREIP Naval Surface Warfare Center, Dahlgren, VA -Universal Camera/Laser Bore Sight Membership ASME

4 Background Original Turbine Blade Conventional Combustion Diffusion Flame Plenty of Cooling Air Turbine Blade (First Uprate) SoLoNOx Combustion Flat Inlet Temperature Profile Unchanged Material Trailing Edge Pressure-Side Hot Spot Trailing Edge Hot Spot

5 Blade Re-design Options Baseline Delta Wings Full Vanes and Delta Wings Extended Bottom Wall, Full Vanes and Delta Wings Internal Cooling Passage Modifications Increase mass Flow Rate Decrease Pressure Drop Improve Heat Transfer or Not Adversely Affect it

6 Design Qualification Testing Temperature Sensitive Paint (Liquid Crystal) Test 3X Stereolithography (SLA) Models Liquid Crystal (LC) Painted on Airfoil External Surface Comparatively Inexpensive Model to Internal LC Models Forward Passage Static Pressure Static Temperature Mid-Passage Static Pressure Static Temperature Flow Bench Mass Flow Rate 3X Baseline Blade

7 Flow Bench flow rate, lbm/s Baseline Blade blade model number LD passage dp 1.17 LD passage dp 1.29 Mid passage dp 1.17 Mid passage dp 1.29 Each Blade Model was Tested on a Flow Bench with a Dp of 1.17 and 1.29 In Leading Passage Delta Wing Reduced Flow (Design Target Not Met) In the Mid-Chord Passage, All Three Modified Blades Increased Flow Slightly Blade Three has the Highest Flow Rate of the Modified Blades

8 Experimental Setup Dual Plenum with Mixing Chamber Baseline Blade Modified Blade Plenum Mixing Chamber TC s & Ps Tests Conducted with Baseline and Modified Blades Side by Side Constant Pressure Constant Flow was Not Tested 195 F Air Supplied to Plenums Inlet Plenum and Blade Static Pressures and Temperatures Measured Video Cameras Recorded Pressure and Suction Side of Blades Blade Dual plenum test fixture

9 Post Processing Liquid Crystal Image Analyzer (LCIA) Convert.WMV to.avi Start Time Pixel Domain Frame Rate Intensity Threshold Results Color Coded Time Image Time to Reach 95 F LCIA Main Interface Video Analyzer Interface Analysis Results Test Video

10 Analysis Requirements Find Internal Heat Transfer Coefficient (HTC) Liquid Crystal on Outer Surface Not Inner Surface Solution for a 1D Convection/ Conduction (HTC) Solve for a Range of HTC Best Fit Curve to HTC vs. Time Solution Create Program to Apply Correlation to LCIA Data 1D convection and conduction diagram

11 Explicit Nodal Model No Exact Solution Explicit Discretized Heat Equations Nodal Conduction Equation hi, Ti ho, To Nodal Convection Equation Biot Number Fourier Number Stability Criteria Nodal diagram of 1D convection and conduction heat transfer

12 ANSYS Model Explicit Discretized Model Validation Using ANSYS Model Arrangement 20 Cases HTC Btu/ft^2 hr ºF Constant Bulk Temperature of 125 F Element Type Plane 77 Node Count 11 Nodes 22 Nodes Screen shot of ANSYS simulation with convective heat transfer conditions applied.

13 1D Transient Conduction Development Constant Bulk Temperature Solutions Follow the Same Trend Discretized Explicit Solution was Considered Adequate Enough to Integrate into an Analysis Program

14 Transient Conduction Program Transient Conduction Analyzer main interface. Test Conditions and Properties Calculations Image Analysis

15 Plotting Solution Calculated Solution Best Fit Curve Multiple Plots Constant vs. Variable Solution Plots Best-Fit Curve Data plotting interface

16 Transient Convection/Conduction Analysis HTC analysis interface Pressure and Suction Side Domain and Section Layout Pixel Locations are Entered into Domain Analyzer

17 Delta Wings The Heat Transfer Coefficient for the Baseline Blade Compared to Modified Blade Two An Overall Ratio was Calculated in Each Domain for a Comparative Analysis Pressure Side Blades 1 and 2 Pressure and Suction HTC Ratios Units: Btu/hr ft^2 ºF B2/B1 PS Domain HTC Ratio Overall 1.21 B2/B1 SS Domain HTC Ratio Overall 1.28 Suction Side Blades 1 and 2

18 Full Vanes And Delta Wings The Heat Transfer Coefficient for the Baseline Blade Compared to Modified Blade Three An Overall Ratio was Calculated in Each Domain for a Comparative Analysis Pressure Side Blades 1 and 3 Pressure and Suction HTC Ratios Units: Btu/hr ft^2 ºF B3/B1 PS Domain HTC Ratio Overall 1.22 B3/B1 SS Domain HTC Ratio Overall 1.21 Suction Side Blades 1 and 3

19 Extended Bottom Wall, Full Vanes and Delta Wings The Heat Transfer Coefficient for the Baseline Blade Compared to Modified Blade Four An Overall Ratio was Calculated in Each Domain for a Comparative Analysis Pressure Side Blades 1 and 4 Pressure and Suction HTC Ratios Units: Btu/hr ft^2 ºF B4/B1 PS Domain HTC Ratio Overall 1.25 B4/B1 SS Domain HTC Ratio Overall 1.27 Suction Side Blades 1 and 4

20 Turbine Nozzle Surface Temperature on Pressure-Side Trailing has High Temperature Proposed Re-Designs Removing Ribs Place Pin Fins on Ribs

21 Design Qualification Testing Temperature Sensitive Paint (Liquid Crystal) Test 2X SLA models Liquid Crystal Painted on Airfoil External Surface Mid-Passage Static Pressure Static Temperature Nozzle Tip Static Temperature 2X SLA Nozzle

22 Experimental Setup Mixing Chamber Tests Conducted With Baseline and Modified Blades Side By Side Constant Pressure Constant Flow Was Not Tested 150 F Air Supplied to Chamber Inlet Chamber and Nozzle Static Pressures and Temperatures Measured Video Cameras Recorded Pressure And Suction Side of Nozzle Nozzle Thermal Test Fixture

23 Nozzle 3.6 PSIG Flow Visually HTC Improved on Modified Designs No-Rib Design Improved the Most Modified Rib Design More Uniform Pressure and Suction Side of nozzle at 3.6 PSIG Flow

24 Nozzle 1.8 PSIG Flow Visually HTC Improved on Modified Designs No-Rib Design Improved the Most Modified Rib Design More Uniform Pressure and Suction Side of nozzle at 1.8 PSIG Flow

25 Development Test and Turbine Assembly 1 Week In Dept. 133 Atmospheric Combustor Combustor and Turbine Assembly GP Shaft Engine Cutaway

26 Conclusion A Program to Calculate HTC or Nussult Number Based on Scaled Model Liquid Crystal Test was Established Cases where LC is Applied to External Surfaces Heat Transfer Augmentation for Three Alternative Designs were Calculated at Five Discrete Areas on the Blade Pressure and Suction Sides The Program can be used for Future Scaled Tests The Augmentation Values can be used to Modify 3D Blade Model for Life Assessment Recommendation A Comparison of an External and Internal LC Model could be used to Validate the Convective and Conduction Analysis Program

27 Acknowledgements Thank You John Mason Dr. Hee-Koo Moon Dr. Luzeng Zhang Dr. Dong Lee Gail Doore Mike Austin Tom Iske Juan Yin Archie French Tim Bridgman Charmaine Gary Interns and Rotations Thank You Dr. Klaus Brun Andrea Barnett Dr. Forrest Ames Learning Experience Basic Pro/E ANSYS Classic Creating EDMs Visual Basic Studio