Incorporation of CFD Generated Aerodynamic Data in Store Separation Predictions

Dunworth, Kevin; Atkins, D J; Lee, Jae

doi:10.2514/6.2005-846

“…Recent advances in computing environments have increased the reliance of CFD methods to simulate store separations. A steady flowfield database with the CFD method substitutes for wind-tunnel data in the trajectory generation program (TGP) [13].…”

Section: Nomenclaturementioning

confidence: 99%

Prediction of Ballistic Separation Effect by Direct Calculation of Incremental Coefficients

Kim

¹

,

Kwon

²

,

Park

³

2010

Journal of Aircraft

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The ballistic separation effect in an aircraft flowfield was predicted via the direct calculation of incremental coefficients. A highly robust flow solver, including a Chimera grid module, was used to create the trajectory of a released store and to calculate incremental coefficients. The incremental coefficients were computed according to the difference between the aerodynamic coefficients in the aircraft flowfield and in the freestream condition. Two different calculations can be executed simultaneously in a parallel computing environment. The aircraft flowfield effect was measured using the incremental coefficients. This method of direct calculation of the incremental coefficients was tested in the case of released stores in two-dimensional subsonic and supersonic flow regions. The accuracy of the unsteady trajectory calculation was verified through comparisons with the captive trajectory system data in the Eglin wing/pylon/store separation problem. The method was then applied to a generic bomb released from a full-body aircraft. The computational results show that the current method is capable of simulating the store trajectory and investigating aircraft flowfield effects. NomenclatureC l , C m , C n = store rolling, pitching, and yawing moment coefficients= contravariant velocities along the generalized coordinates U g = grid velocity u, v, w = Cartesian velocity components C x = incremental force coefficient in the x direction , p, e = density, pressure, and total energy , , = roll, yaw, and pitch angles

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Prediction of Ballistic Separation Effect by Direct Calculation of Incremental Coefficients

Kim

¹

,

Kwon

²

,

Park

³

2008

Lecture Notes in Computational Science and Engineering

1

0

View full text Add to dashboard Cite

The ballistic separation effect in an aircraft flowfield was predicted via the direct calculation of incremental coefficients. A highly robust flow solver, including a Chimera grid module, was used to create the trajectory of a released store and to calculate incremental coefficients. The incremental coefficients were computed according to the difference between the aerodynamic coefficients in the aircraft flowfield and in the freestream condition. Two different calculations can be executed simultaneously in a parallel computing environment. The aircraft flowfield effect was measured using the incremental coefficients. This method of direct calculation of the incremental coefficients was tested in the case of released stores in two-dimensional subsonic and supersonic flow regions. The accuracy of the unsteady trajectory calculation was verified through comparisons with the captive trajectory system data in the Eglin wing/pylon/store separation problem. The method was then applied to a generic bomb released from a full-body aircraft. The computational results show that the current method is capable of simulating the store trajectory and investigating aircraft flowfield effects. NomenclatureC l , C m , C n = store rolling, pitching, and yawing moment coefficients= contravariant velocities along the generalized coordinates U g = grid velocity u, v, w = Cartesian velocity components C x = incremental force coefficient in the x direction , p, e = density, pressure, and total energy , , = roll, yaw, and pitch angles

show abstract