heat transfer analyses of internal cooling passages of turbine … · 2017. 4. 19. · full vanes...

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

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)

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

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

Blade Re-design Options

Extended Bottom Wall, Full Vanes and Delta Wings

Full Vanes and Delta Wings

Delta Wings Baseline

•  Internal Cooling Passage Modifications –  Increase mass Flow Rate

–  Decrease Pressure Drop

–  Improve Heat Transfer or Not Adversely Affect it

Design Qualification Testing

•  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

Temperature Sensitive Paint (Liquid Crystal) Test

Flow Bench

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

0.05

0 1 2 3 4

blade model number

flow

rate

, lbm

/s

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

Baseline Blade

Experimental Setup

•  Dual Plenum with Mixing Chamber

•  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

Baseline Blade

Modified Blade Mixing Chamber

Plenum TC’s & Ps

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

Test Video

Analysis Results

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

Explicit Nodal Model

hi, Ti ho, To

Explicit Discretized Heat Equations

Nodal Conduction Equation

Nodal Convection Equation

Biot Number

Stability Criteria

Fourier Number Nodal diagram of 1D convection

and conduction heat transfer

No Exact Solution

ANSYS Model

•  Model Arrangement –  20 Cases –  HTC .88-17.6 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.

Explicit Discretized Model Validation Using ANSYS

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

Transient Conduction Program

•  Test Conditions and Properties •  Calculations •  Image Analysis

Transient Conduction Analyzer main interface.

Plotting Solution

•  Multiple Plots

•  Constant vs. Variable Solution

•  Plots Best-Fit Curve

Data plotting interface

Calculated Solution Best Fit Curve

Transient Convection/Conduction Analysis

•  Pressure and Suction Side Domain and Section Layout

•  Pixel Locations are Entered into Domain Analyzer

HTC analysis interface

Delta Wings

Domain HTC Ratio1 1.422 1.023 1.274 1.135 1.20

Overall 1.21

B2/B1 PSDomain HTC Ratio

1 1.132 1.393 1.244 1.225 1.44

Overall 1.28

B2/B1 SS

•  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

Suction Side Blades 1 and 2

Pressure and Suction HTC Ratios

Units: Btu/hr ft^2 ºF

Full Vanes And Delta Wings

Domain HTC Ratio1 1.302 1.263 1.094 1.205 1.20

Overall 1.21

B3/B1 SSDomain HTC Ratio

1 1.232 1.293 1.294 1.145 1.16

Overall 1.22

B3/B1 PS




•  The Heat Transfer Coefficient for the Baseline Blade Compared to Modified Blade Three



Extended Bottom Wall, Full Vanes and Delta Wings

Domain HTC Ratio1 1.122 1.223 1.234 1.335 1.44

Overall 1.27

B4/B1 SSDomain HTC Ratio

1 1.322 1.303 1.254 1.175 1.20

Overall 1.25

B4/B1 PS





•  The Heat Transfer Coefficient for the Baseline Blade Compared to Modified Blade Four


Turbine Nozzle

•  Surface Temperature on Pressure-Side Trailing has High Temperature

•  Proposed Re-Designs

–  Removing Ribs

–  Place Pin Fins on Ribs

Design Qualification Testing

•  2X SLA models

•  Liquid Crystal Painted on Airfoil External Surface

•  Mid-Passage –  Static Pressure

–  Static Temperature

•  Nozzle Tip –  Static Temperature

Temperature Sensitive Paint (Liquid Crystal) Test

2X SLA Nozzle

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

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

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

Development Test and Turbine Assembly

•  1 Week In Dept. 133

•  Atmospheric Combustor

•  Combustor and Turbine Assembly –  GP Shaft

Engine Cutaway

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

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

Learning Experience

•  Basic Pro/E

•  ANSYS Classic

• Creating EDMs

• Visual Basic Studio

Thank You

•  Dr. Klaus Brun

•  Andrea Barnett

•  Dr. Forrest Ames

heat transfer analyses of internal cooling passages of turbine … · 2017. 4. 19. · full vanes...

Documents