Transcript Fans, Compressors, and Turbines

Fans, Compressors, and Turbines
EGR 4347
Analysis and Design of Propulsion systems
General Electric CF6-50
CFM-56
F100-PW-220 Turbofan Engine
F-404 vs. J79
GP 7200 – GE and P&W
For Airbus 380
Bird Strikes
Results
Results
Results
Compressors
• AXIAL
• CENTRIFUGAL
Axial Compressor
Ps
V2
PT
C1
INLET GUIDE VANES
W1
W1
C1
U
U
FIRST STAGE BLADE
W2
C2
W2
C2
U
FIRST STAGE VANE
W3
C3
W3
U
U
SECOND STAGE BLADE
W4
C3
C4
W4
C4
U
SECOND STAGE VANE
C5
Complex Flow in Compressors
General Electric
http://www.pr.afrl.af.mil/divisions/prt/ihptet/brochure/FansCom.htm
JTAGG III Advanced
Concept Centrifugal
Impeller with independent
inducer and exducer will
provide higher pressure ratio
and efficiency.
Integrating Forward Sweep and
Splitter Technology are key features
to achieving high efficiency and high JTDE Forward Swept Fan
Blisk will be the first large
pressure ratio. This stage will be
forward swept rotor to be tested
utilized as the JTAGG III low
in a demonstrator engine.
pressure compressor.
The compression systems of tomorrow's aircraft gas turbine engines must have reduced weight,
provide higher performance, and be more robust in order to develop pressures of up to seventy
atmospheres to meet IHPTET Phase III goals. Significant progress has already been achieved
through the application of advanced Computational Fluid Dynamics (CFD) analysis tools,
innovative aerodynamic and mechanical design schemes, and high specific strength material
systems. Aerodynamic sweep and "splittered" rotor designs provide higher pressure ratios and
efficiencies with a significant improvement in stability margin. A Phase III two stage fan
combined with a four stage compressor will provide the same performance as the three stage fan
and ten stage compressor in the F100 engine, dramatically reducing the number of parts while
meeting Phase III production and maintenance cost goals. Hollow fan blades and organic and
metal matrix composite rotating and static structures significantly reduce weight. The core
A Forged Orthorhombic
driven fan enables the variable cycle engine to operate as a turbofan or turbojet, vastly
Transformed Super Alpha-2
broadening operational capability. Rotor and stator airfoil designs, analyzed with advanced
Billet will be bonded to
unsteady aerodynamic analysis codes, reduce aeromechanical design iterations which reduce
Gamma TiAl to form a novel,
design costs while increasing correctness. Numerous compression system designs have been
dual alloy impeller.
tested and analyzed at the Air Force Research Laboratory's Compressor Research Facility (CRF)
http://www.pr.afrl.af.mil/divisions/prt/ihp
and Compressor Aero Research Lab (CARL).
tet/brochure/Materials.htm
This 4-stage ATEGG Compressor
Rig, the highest loaded compressor
ever built with acceptable stall margin
and efficiency characteristics, meets
the Phase III stage loading goals.
TURBINES
• PURPOSE: Convert KE into shaft HP
• ENVIRONMENT:
– Favorable Pressure Gradient
• more turning, more work per stage relative to
compressor
–
–
–
–
Temps exceed material limits; cooling req’d
High stresses due to temp and rotation
Fixed geometry
3/4 of energy available after combustor used
to drive compressor
Parameters Affecting Turbine Blade
Design
Vibration Environment
Tip Shroud
Number of Blades
Airfoil Shape
Inlet Temperature
Blade Cooling
Material
Trailing-Edge Thickness
Allowable Stress Levels (AN2)
(N = Speed, RPM)
Service Life Requirements
TURBINE ANALYSIS - Velocity
Triangles
TURBINE COOLING
• WHY?
• TYPES OF DESIGNS
• EFFECTIVENESS
• THERMAL BARRIER COATING
WHY?
• Combustor gas temps exceed metal melting
temps
• To increase thrust-to-weight, temps increase
faster than material capability
• High metal temps weaken blade/reduce life
• Cooling air can be distributed to reduce large
temperature gradients (reduces thermal fatigue)
- if not done properly, the reverse can happen
TURBINE COOLING
TURBINE COOLING
http://www.pr.afrl.af.mil/divisions/prt/ihptet/brochure/Turbines.htm
Castcool® High and Low Pressure
Turbine Blades for ATEGG and JTDE will
demonstrate capability at conditions more
than 100°F above the Phase II turbine
temperature objective.
Improved Thermal Barrier
Coatings which have reduced
conductivity and weight will
enable this turbine blade to
meet Phase II and III turbine
temperature goals.
High Work Turbine Design
demonstrates Phase II
performance and cooling
technology in rig and JTAGG I
engine testing using advanced
aerodynamics and cooling
schemes in diffusion bonded
airfoils.
Modern turbines must maintain a balance between high performance, affordability, and design robustness in order to maximize engine payoff.
Achieving production part cost, along with substantially improved life-cycle costs, requires development of significantly enhanced manufacturing
techniques; strong, low density, affordable materials; and the use of concurrent engineering practices from initial design concept to "fielding" of
the part. Development for component robustness and a need for long intervals between inspections and overhauls require parts with improved
fatigue behavior. High performance cooling technologies will maximize the effectiveness of reduced cooling flows while improving life through
the application of novel structural designs. Special emphasis is placed on enhanced analysis techniques, including 3-D time accurate
computational codes, to provide better understanding of the aerodynamic and heat transfer mechanisms occurring in extremely complex airfoils.
Using the Air Force Research Laboratory 's Turbine Research Facility (TRF), advanced, short duration test methods are being applied to validate
turbine aerodynamic and cooling designs. These test methods will be extended to measure turbine structural dynamics and high cycle fatigue
characteristics.