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Computational and Experimental Thermal Sciences

Focus Area

Dr. Ray HixonFocus Area Leader

August 17, 2011

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Gas Turbine Engine Research

Current Projects

• Characterization of Bearings

• Engine System Simulation

• Combustor Flow

• Manufacturing System Optimization

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Tribology Research Facility

High Speed, Magnetic Levitated, Air Bearing Test Stand to Simulate Actual Rotor Behavior in Rotating Machines Up to 75,000 rpm

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Small Gas Turbine Engine Facility

Test Cell and Control RoomSupport Infrastructure – air supply, utilities, etc. Instrumentation and Data Acquisition System

A Flexible Facility for Testing Rotating Components and Engines Operating at High Speed ~ 150,000 RPM

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Dr. K.C. Masiulaniec & Dr. A.A. AfjehSmall Gas Turbine Slinger Design for Combustion Chamber

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• The NASA GRC BASS code is a general-purpose nonlinear CAA/LES solver:

– 2D/3D Navier-Stokes or Euler equations.

– Curvilinear coordinates with grid motion for flexibility.

– Block-structured grids for efficient computation of complex geometries.

– Up to 6th order compact differencing in space.

– 4th order optimized explicit multi-time-step time marching.

– Blended 2nd/10th order shock capturing artificial dissipation.

– Fortran 2003, MPI-1 parallelization for portability and maintainability.

• This work is supported by the Subsonic Fixed Wing Project of the NASA Fundamental Aeronautics Program.

• Dr. Edmane Envia of NASA Glenn is the Technical Monitor.

NASA GRC BASS Code (Hixon)

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Direct Prediction of Turbulent Wake Noise with Computational Aeroacoustics (Sescu/Hixon)

• Given experimental turbulence measurements at two axial locations between the rotor and stator in the SDT rig, the synthetic turbulence generation method is used to impose turbulence at the upstream location.

• The predicted turbulence at the downstream location is compared to the data as a sanity check of the method.

Perturbation vorticity magnitude snapshot

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3D Synthetic Turbulence Test (2)

BASS BASSExperiment Experiment

Upstream Downstream

TKE

u’ snapshot

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EVA Verification of BASS Multi-Time-Stepping AB4M Implementation (Ingraham/Hixon)

Can you prove that your code is solving the governing equations?

Because EVA is an external tool, the actual implementation of the AB4M method in the BASS code can be verified…

…each with different time steps.

Four grid blocks in the domain…

As the time step is reduced, the BASS solution of the nonlinear Euler equations converges to the EVA result…

…showing fourth order accuracy!

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Research Facilities

• Wind Tunnel Laboratory

– 3-ft x 3-ft closed-loop wind tunnel

– Force balance, PSI pressure scanners, hot-wire anemometer, flow visualizations.• Optical Flow Diagnostics Laboratory

– Two-component fiber-optic laser Doppler anemometer (LDA), Particle Image Velocimeter (PIV), and various optical devices.

• Others

– Semi-anechoic chamber, high-speed jet, water channel, high-speed wind tunnel (under construction), Ohio Super computer (CFD)

Research Areas

• Bio-fluid mechanics

– human lung flow and phonation studies

• Aerodynamics

– advances air-vehicle flow controls using mechanical and pneumatic devices, and plasmas

Project Funding Sources

• US Army

• US Navy

• US Air Force

• NIH

Array of 8 Microvalves

Experimental Fluid Mechanics ResearchExperimental Fluid Mechanics ResearchT. Terry Ng. Professor of Mechanical EngineeringT. Terry Ng. Professor of Mechanical Engineering

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UU22NCLE Flow Solver (Sheng)NCLE Flow Solver (Sheng)

• The UT-U2NCLE code is a general purpose unstructured RANS CFD solver for fixed and rotary wing aircraft and turbomachinery:

– Parallel solver for 3D Navier-Stokes or Euler equations

– Unstructured mixed-element meshes with grid motion and deformation capabilities

– Incompressible, compressible, and arbitrary Mach number flows

– Higher order (> 2nd) spatial discretization schemes with 2nd order temporal accuracy

– Implicit Newton’s method to time marching

– Spalart-Allmaras and k-e, k-w, q-w two-equation turbulence models

• This code is being routinely used by Bell Helicopter engineers for rotorcraft aerodynamic analysis and design optimization

• It has been supported by multiple DoD agencies, NASA, and industries for the past 17 years

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Blade Pitch Interface

Blade Flap Interface

Blade

Mesh Motion & DeformationMesh Motion & Deformation

Radial Basis Functions Popular approximation for

scattered data, usually used for computer graphics, imaging

• Most efficient and robust mesh deformation method for large-scale viscous meshes

• Collaborating with Prof. Chris Allen (Univ. of Bristol)

Sliding Interfaces• Rigid and prescribed blade motion

• Fully conservative

• No interpolation needed

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Transitional & Rotational MovementsTransitional & Rotational Movements

20% chord length

40 degrees

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Hybrid CFD/Wake ModelHybrid CFD/Wake Model

Bell M427 Main Rotor Blade Georgia Tech Lagrangian Free Wake Model (Prof. Sankar)

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CFD/CSD CouplingCFD/CSD Coupling

U2NCLE/DYMORE Coupling(with Prof. Sankar)

CFD Wetted Surface

Structural Mesh

Surface/Volume Deformation(with Prof. Chris Allen)

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Legal Aspects of Engineering• Patent Law

• Contracts

• Product Safety and Liability

• Engineering Entrepreneurs

• Environmental Law

• White Collar Crime

Dr. Douglas Oliver, PE, Esq.

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Thermal Science Focus Group Faculty

Dr. A. Afjeh, Professor• Fluid Dynamics, Propulsion Systems,

Computational Method, Energy Conversion Systems.

Dr. S. Cioc, Assistant Professor• Thermodynamics, Conduction, Heat

Transfer, Tribology

Dr. R. Hixon, Associate Professor• Computational Aeroacoustics,

Computational Fluid Dynamics, Large-Eddy Simulations, Turbulence, Fluid-Structures Interaction, Trustworthy Computing.

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Thermal Science Focus Group Faculty

Dr. K. C. Masiulaniec, Associate Professor• Phase Change Heat Transfer, Convective

Heat Transfer from Roughened Surfaces, High Temperature Heat Exchangers and Industrial Furnaces.

Dr. T. Ng, Professor• Aerodynamics, Stability, Turbulence,

Experimental Methods.

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Thermal Science Focus Group Faculty

Dr. D. Oliver, Associate Professor• Engineering Law and Intellectual Property,

Heat Transfer, Mathematical Modeling, Microgravity Flow Dynamics.

Dr. C. Sheng, Associate Professor• Computational Fluid Dynamics, High-

Accuracy Unstructured Grid Methods, Preconditioning Methods.

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MS Degree Course Requirements

Core courses (9 hours)• MIME 6980: Intermediate Fluid

Mechanics and Heat Transfer

• Either: MIME 69xx: Advanced Heat Transfer MIME 69xx: Advanced Fluid Mechanics

• Either: MIME 6440: Computational Fluid Dynamics

I MIME 6450: Experimental Fluid Mechanics

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MS Degree Course Requirements

Engineering Mathematics (3 credits)• Ordinary Differential Equations:

- MIME 6000/8000: Advanced Engineering Math I- Math 5740/7740: Advanced Applied

Mathematics I- Math 5800/7800: Ordinary Differential Equations

• Graduate Level course in Engineering or Mathematics related to the student’s area of specialization.- Get the list of approved courses in the office.