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NASA C3X

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Applications

      • Surface temperature distribution
      • Convective cooling
      • Film cooling
      • Thermal stress analysis

Models active in this Demonstration Case

  • Compressible flow
  • Ideal gases
  • Conjugate heat transfer
  • Turbulence model
  • Periodic boundary

Objective

To validate the accuracy of conjugate heat transfer module against a well documented and challenging NASA experimental study.

Case Description

A turbine blade with a film cooling combined with convective cooling configuration was used with high speed flow. Surface temperature profiles from CFD and conjugate heat transfer solutions are compared against the experimental data. 

Description & Performance Data

final_bc.png

Fig. 1 - Geometry & Boundary

Fluid Settings

Gas Constant                           R           =287J/ (kg k)

Viscosity                                   η           = 1.325e-005~3.388e-005 Pa-s

Specific Heat                            Cp         = 1007~1075 J/(kg k)

Thermal Conductivity                k           = 0.0181~0.0524 W/(m k)

Vane: ASTM 310 stainless steel

Density                                     rho        = 7854 kg/m3

Specific Heat                            Cp        = 434 J(kg/k)

Thermal Conductivity               k           = 6.811+0.020176*T W (m k)

 

EXN/View: Mesh, Physics and Solver Settings

Fig.2-7 show the setup of simulation using EXN/View. It allows two types (Fluid and Solid) and multiple cell families, also the conjugate heat transfer boundary and the periodic boundary through a true non-matching general connectivity.  

EXN1.png 

 Fig 2. EXN/Aero Setup Cell Family - 1

exn2.png

  Fig 3. EXN/Aero Setup Cell Family - 2

 

exn3.png

Fig 4. EXN/Aero Periodic Boundary - 1

  

exn4.png

Fig 5. EXN/Aero Periodic Boundary - 2

 

exn5.png

Fig 6. EXN/Aero CHT Boundary - 1

 

exn6.png

Fig 7. EXN/Aero CHT Boundary - 2

Results

The Mach number and Velocity plots are shown in Fig.8-9. Fig.10 shows the vane wall surface temperature distribution. The center line temperature distribution on the vane wall surface is compared against the experimental data in Fig.11. In Fig.11, the x-axis is the normalized airfoil location (negative is the suction side, and positive is the pressure side), and the y-axis is the wall temperature normalized by the reference temperature.  

Screen Shot 2018-01-29 at 16.21.10.png

Fig 8. Results - Mach Number

Screen Shot 2018-01-29 at 16.22.09.png

 Fig 9. Results - Velocity

Screen Shot 2018-01-29 at 16.22.48.png

Fig 10. Results - Vane Wall Surface Temperature

 

Table_airprop.png

 Fig 11. Results - Vane Wall Center Line Temp Distribution

 

Simulation Outcomes, Timing, and External Factors

 

 Table 2 - Simulation performance outcomes

Reporting Item

EXN/Aero

CPU Type

3 Xeon @2.6GHz

GPU Type

1 K80

Flow Type

Compressible; Air, Ideal Gas

Mesh Size

13 Million

Simulation Type

Steady-State

Time Step Size

5e-5 sec

Real Time per Time Step

30 sec

Time to Completion 10000 iterations, equivalent to 80 hours

 

Keywords

  • Periodic Boundary
  • Internal Flow
  • Steady State
  • RANS SST k-ω
  • Transonic
  • Conjugate Heat Transfer
  • Double Precision
 
2018-02-4 | Categories: CFD

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