## OPENFOAM VALIDATION CASES

**High speed flow around a NACA 0012 airfoil - Compressible flow**

Hereafter, we compute the flow around a NACA 0012 airfoil. In this case, we compare the numerical results obtained with OpenFOAM, against the experimental results presented in references [1, 2, 3].

The simulations were conducted for an angle of attack of 1.55 degrees, and a freestream Mach number of 0.7. The static pressure was set to 73048 Pa and the static temperature to 283.24 K. To convert the total pressure and total temperature reported in references [1, 2, 3], we used the isentropic flow equations.

In this validation case, we used the k-Omega SST turbulence model with wall functions, and the y+ value ranges between 30 and 300. This is a high-speed compressible case; therefore, a robust and accurate numerical method is required.

Left image: velocity magnitude contours. Right image: pressure contours. |

Left image: pressure coefficient on the airfoil surface. Right image: y-plus value on the airfoil surface. |

Left image: lift coefficient iterative history. Right image: drag coefficient iterative history. |

Residuals |

AOA | \( c_d \) experimental | \( c_d \) OpenFOAM | Percentage Error (%) |
---|---|---|---|

\( 1.55^{\circ} \) | 0.0079 | 0.0078 | 1.28 |

AOA | \( c_l \) experimental | \( c_l \) OpenFOAM | Percentage Error (%) |
---|---|---|---|

\( 1.55^{\circ} \) | 0.241 | 0.2415 | -0.2 |

*warning* The experimental values were extracted from plots illustrated in references [1,2,3].

We can not guarantee the accuracy or precision of this information.

**References:**

[1] Numerical Simulation of Viscous Transonic Airfoil Flows. NASA Ames Research Center, AIAA-87- 0416, 1987.

[2] Two-Dimensional Aerodynamic Characteristics of the NACA 0012 Airfoil in the Langley 8-foot Transonic Pressure Tunnel. NASA Ames Research Center, NASA TM 81927, 1981.

[3] Computational Fluid Dynamics Drag Prediction-Results from the Viscous Transonic Airfoil Workshop. NASA Ames Research Center, NASA TM 100095, 1988.