Numerical simulation of a store in controlled separation

Nichols, R.; Denny, A.

doi:10.2514/6.1999-3128

Cited by 3 publications

(2 citation statements)

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“…One significant documented contribution to controlled store separation comes from R.H. Nichols and A.G. Denny (Arnold Engineering Development Center). 3 The authors present a case study for the numerical simulation of a non-thrusted AIM-120C Advanced Medium Range Air-to-Air Missile (AMRAAM) in controlled separation from a wing station of the F-15E Strike Eagle. The AMRAAM is eject-launched (as opposed to rail-launched like many air-to-air missiles) from the F-15E and the motor does not fire until after the store is away from the aircraft.…”

Section: Overviewmentioning

confidence: 99%

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Trajectory Optimization for Guided Store Separation

Carter

Lind

2012

AIAA Guidance, Navigation, and Control Conference

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Combat aircraft utilize expendable stores such as missiles, bombs, flares, and external tanks to execute their missions. Safe and acceptable separation of these stores from the parent aircraft is essential for meeting the mission objectives. In many cases, the employed missile or bomb includes an onboard guidance and control system to enable precise engagement of the selected target. Due to potential interference, the guidance and control system is usually not activated until the store is sufficiently far away from the aircraft. This delay may result in large perturbations from the desired flight attitude caused by separation transients, significantly reducing the effectiveness of the store and jeopardizing mission objectives. The purpose of this paper is to present the investigation of a transitional control system to guide the store during separation. The transitional control system, or "store separation autopilot", explicitly accounts for the nonuniform flow field through characterization of the spatially variant aerodynamics of the store during separation. This approach can be used to mitigate aircraft-store interference and leverage aerodynamic interaction to improve separation characteristics. Optimal control theory is used to determine an openloop optimal trajectory and neighboring optimal control is used to implement a closed-loop store separation autopilot along the optimal trajectory. An example is shown based on a representative store separating from an F-16 aircraft. I. OverviewS tore separation engineering, a subset of aircraft-store compatibility, is concerned with the flight characteristics of a store in proximity of the aircraft and other stores. A store released from an aircraft in flight must traverse a nonuniform and unsteady flow field that may include complex shock interactions, large velocity gradients, regions of locally separated or reversed airflow, and severe flow angularity in the form of sidewash and downwash. Stores released from an internal weapons bay may also be subjected to a wake disturbance from the spoiler, dynamic pressure and velocity gradients across the shear layer, high frequency vibrations due to acoustic noise, and large perturbations in flow properties due to cavity oscillations.Although the region of nonuniform flow near the aircraft is exceedingly small compared to the full length of the ballistic or fly-out trajectory, the effects are significant. The flow field characteristics may cause the store to exhibit behavior that compromises the safety of the airframe and crew or that compromises the effectiveness of the store itself. Prediction of the flight characteristics of the store in the vicinity of the aircraft is therefore vitally important for ensuring the safety and effectiveness of the release.Modern sophisticated "smart" weapons are equipped with sensitive onboard electronics including inertial measurement systems, GPS units, sensors, seekers, and guidance computers. Standoff capability (the desirable ability to release a munition far away from the intended targ...

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Section: Overviewmentioning

confidence: 99%

“…In particular, the objective is to minimize the Bolza form of the cost functional (1) subject to the dynamic constraints (2), the inequality path and control constraints (3), and the boundary conditions (4).…”

Section: Iia1 First Order Optimality Conditionsmentioning

confidence: 99%

Trajectory Optimization for Guided Store Separation

Carter

Lind

2012

AIAA Guidance, Navigation, and Control Conference

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Trajectory Simulations Should Match Flight Tests and Other Lessons Learned in 30 Years of Store-Separation Analysis

Keen

Morgret

Langham

et al. 2009

47th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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Cfd Simulations of Store Separation: An Indian Perspective

Debasis Chakraborty

2023

joast

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CFD analysis played a very major role in predicting the safe separation of many stores including missiles, guided bombs, drop tanks from various airborne platforms namely, fighter aircraft, helicopters etc. Number of indigenous CFD based stores separation suites are developed by coupling flow solvers, 6 Degrees-of-freedom (6DOF) trajectory programs and efficient pre and post processors. These packages were validated against reliable experimental results and were applied to many practical applications. These analyses gave very good confidence to the designers, test pilots and certifying agencies to clear the flight trials without much wind tunnel testing. This paper highlights the author’s experience of use of CFD techniques to predict external store separation from fighter aircraft pertaining to Indian system.

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Numerical simulation of a store in controlled separation

Cited by 3 publications

References 1 publication

Trajectory Optimization for Guided Store Separation

Trajectory Optimization for Guided Store Separation

Trajectory Simulations Should Match Flight Tests and Other Lessons Learned in 30 Years of Store-Separation Analysis

Cfd Simulations of Store Separation: An Indian Perspective

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