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Efficiency Improvement by Endwall Contouring. Endwall Contouring, Using Continuous Diffusion Technology, A Breakthrough Technology and its Application to a Three-Stage High Pressure Turbine Introduced by Turbomachinery Performance and Flow Research Laboratory, Texas A&M University.
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Efficiency Improvement by Endwall Contouring Endwall Contouring, Using Continuous Diffusion Technology, A Breakthrough Technology and its Application to a Three-Stage High Pressure Turbine Introduced by Turbomachinery Performance and Flow Research Laboratory, Texas A&M University Sponsored by DOE, National Energy Technology Laboratory TPFL: The Turbomachinery Performance and Flow Research Laboratory Texas A&M University M. T. Schobeiri
Introduction: Endwall Secondary Flow, Reduction • Pressure difference between suction and pressure side causes: • Systems of secondary vortices • Generation of induced drag forces • Total pressure reduction • Secondary flow losses • Efficiency decrease TPFL: The Turbomachinery Performance and Flow Research Laboratory Texas A&M University M. T. Schobeiri
Breakthrough Technology, Disclosure of Invention TAMUS 3259 Unlike methods available in the literature, the Continuous Diffusion Technology introduced by TPFL is physics based and can be applied to P, IP, and LP turbines and compressors regardless the load coefficient, flow coefficient and degree of reaction. Details are explained in the ASME paper GT2011-45931 Presented at the ASME-IGTI-Turbo-Expo 2011, June 06-10, 2011, Vancouver, Canada TPFL: The Turbomachinery Performance and Flow Research Laboratory Texas A&M University M. T. Schobeiri
TPFL Research Turbine Used for Endwall Contouring Research Mainstream Flow Platform Discrete Hole Film Cooling Rotor-Seal Ejection Cooling Tow Independent Coolant Loops for Coolant Injection from Stator-Rotor Seal and Downstream Film Cooling Holes A Three-stage Turbine Rotor with two Independent Coolant Flow Loops TPFL: The Turbomachinery Performance and Flow Research Laboratory Texas A&M University M. T. Schobeiri
Numerical Methodology • Steady state models used, convergence was assessed through monitoring of: • Equation RMS and maximum residual values • Inlet and exit mass flow • Area-averaged pressure and velocity at turbine exit • Turbulence model • Shear Stress Transport (SST) model • CFX Automatic wall treatment employed • Switches between wall functions to a low-Reynolds number near wall formulation • Requires y+<2, and at least near-wall nodes • Boundary conditions • Ptin, Ttin, Pb • Fixed rotation speed • Adiabatic and non-slip conditions on the wall TPFL: The Turbomachinery Performance and Flow Research Laboratory Texas A&M University
Numerical Simulation Mesh Rotor mesh has over 2 million elements Extensive grid sensitivity tests Wall regions use 22 nodes The entire model involves over 9 million elements TPFL: The Turbomachinery Performance and Flow Research Laboratory Texas A&M University M. T. Schobeiri
Blade Loading of Second Rotor Geometry needs to be further optimized Geometry needs to be further optimized. Blade Loading at Hub TPFL: The Turbomachinery Performance and Flow Research Laboratory Texas A&M University M. T. Schobeiri
Blade Loading of Second Rotor Geometry needs to be further optimized. Blade Loading at 2% Span Rad distance from hub 1.3 mm Blade Loading at Hub Pressure distribution at two different span locations TPFL: The Turbomachinery Performance and Flow Research Laboratory Texas A&M University M. T. Schobeiri
Continuous Diffusion Technology Applied to Endwall sign The design of contouring considers both the direction of streamlines and pressure gradient near hub. Currently there is no positive portion. TPFL: The Turbomachinery Performance and Flow Research Laboratory Texas A&M University M. T. Schobeiri
Pressure Distribution at Hub partial contouring extended new contouring reference case Comparison of pressure distributions TPFL: The Turbomachinery Performance and Flow Research Laboratory Texas A&M University M. T. Schobeiri
Total Pressure Loss Coefficient for Second Rotor TPFL: The Turbomachinery Performance and Flow Research Laboratory Texas A&M University M. T. Schobeiri
Efficiency Improvement Using New Technology TPFL Conventional Designs From Literature TPFL: The Turbomachinery Performance and Flow Research Laboratory Texas A&M University M. T. Schobeiri