On Aerodynamic Modelling and Simulation of the Dynamic Interface

The past decade has seen significant advancements in modelling and simulation of the dynamic interface. The goal of the initial work in this area was to reduce the costs associated with first-of-class flight trials, and to deal with the backlog of aircraft-ship combinations for which flight-clearance envelopes were minimal or non-existent. A decade ago, piloted simulation of the dynamic interface appeared to be the obvious way to overcome these deficiencies. Validated models of fixed-wing and rotorcraft were in existence, and work began to combine these models with prescribed weather/lighting conditions (wind, rain, snow, fog, night, etc.), ship visuals, and motion. It had been envisioned that through the use of high-fidelity flight simulation, a test pilot could rapidly and safely determine the flight envelope boundaries without resorting to, or at least minimizing, flight trials. During the past decade, significant advancements in simulation fidelity did transpire due to increased computational power, an improved understanding of airwakes, and enhanced simulation capabilities. The article describes some of the fundamental and applied research that contributed to the improved fidelity, much of it gained in a collaborative fashion. To date, modelling and simulation technologies have not advanced to the state where they can replace flight tests to derive flight-clearance envelopes, but they have approached the point where they can augment flight tests and serve in a training capacity. The accrual of a training benefit has recently emerged and is a significant, though unplanned, dividend from the efforts directed towards flight-envelope prediction. This article sets out to examine some of the strengths and deficiencies of the current capabilities, and provides a discussion of the way forward. Modelling and simulation of the dynamic interface are discussed in a broad context, wherein they are defined to include non-piloted, non-real-time activities. The article will provide a critical review of many of these efforts to date, focusing primarily on aerodynamic issues. The article also discusses the challenges which are present for rotary-wing operations, for both small and large ships. It compares the environment in both cases and how that impacts the simulation requirements.