SBIR-STTR Award

The ability to refuel piloted aircraft in flight is considered a strategic military asset and has been a critical element of success in nearly every US and NATO military engagement of the jet age. Equally important going forward will be the ability to perform Autonomous Aerial Refueling (AAR) and refuel unmanned aircraft in flight. In order to properly set the requirements for AAR, a high-fidelity aerial refueling simulation is needed to predict performance and refine requirements. Modeling and simulation of aerial refueling provides an invaluable capability in designing and/or evaluating an AAR system allowing the Navy to accurately assess drogue stabilization, closure rates, turbulence and the bow wave effect, hose reel tension failure implications, and defining and predicting success rates. The proposed solution set forth in this effort involves developing a modified vortex lattice method (VLM) that is customized for calculating the incremental forces and moments on a generic receiver aircraft resulting from a non-uniform flow-field of a tanker aircraft. In the remainder of this proposal, this method is referred to as an incremental vortex lattice method or IVLM.

Benefit:
Beyond aerial refueling modeling and simulation, we envision derivative modeling and simulation tools supporting formation flight, aircraft separation standards and naval ship wake effects. Another benefit of the research and development arising from this SBIR effort is the increased fidelity of the Navys refueling hose/drogue model. This model currently uses a single component estimate of the tanker downwash which is based on the tanker lift coefficient and airspeed, and can benefit directly from immersing the hose/drogue model in an accurate tanker wake.

Keywords:
aerial refueling, aerial refueling, Aerodynamics, Vortex lattice method, Airwake, viscous analysis, Formation Flying, inviscid analysis

The ability to refuel piloted aircraft in flight is considered a strategic military asset and has been a critical element of success in nearly every US and NATO military engagement of the jet age. Equally important going forward will be the ability to perform Autonomous Aerial Refueling (AAR) and refuel unmanned aircraft in flight. In order to properly set the requirements for AAR, a high-fidelity aerial refueling simulation is needed to predict performance and refine requirements. Modeling and simulation of aerial refueling provides an invaluable capability in designing and/or evaluating an AAR system allowing the Navy to accurately assess drogue stabilization, closure rates, turbulence and the bow wave effect, hose reel tension failure implications, and defining and predicting success rates. The proposed solution set forth in this effort involves developing a modified vortex lattice method (VLM) that is customized for calculating the incremental forces and moments on a generic receiver aircraft resulting from a non-uniform flow-field of a tanker aircraft. In the remainder of this proposal, this method is referred to as an incremental vortex lattice method or IVLM.

Benefit:
Beyond aerial refueling modeling and simulation, we envision derivative modeling and simulation tools supporting formation flight, aircraft separation standards and naval ship wake effects. Another benefit of the research and development arising from this SBIR effort is the increased fidelity of the Navys refueling hose/drogue model. This model currently uses a single component estimate of the tanker downwash which is based on the tanker lift coefficient and airspeed, and can benefit directly from immersing the hose/drogue model in an accurate tanker wake.

Keywords:
Vortex lattice method, aerial refueling, Aerodynamics, inviscid analysis, viscous analysis, Airwake, Formation Flying