Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to improve fluid flow simulations. An example apparatus includes a property identifier to, prior to execution of the computer-based model, identify donors and recipients representative of one or more model regions of the computer-based model to simulate for a plurality of time steps including a first time step and a second time step, the donors having donor properties, in response to computing a flow field for the first time step of the computer-based model, a property extractor to extract the donor properties from extraction surfaces of the donors, and a property assignor to assign the donor properties to boundary surfaces of respective ones of the recipients, and a flow field generator to generate an output flow field for the second time step based on the recipients having the assigned donor properties.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to improve fluid flow simulations. An example apparatus includes a property identifier to, prior to execution of the computer-based model, identify donors and recipients representative of one or more model regions of the computer-based model to simulate for a plurality of time steps including a first time step and a second time step, the donors having donor properties, in response to computing a flow field for the first time step of the computer-based model, a property extractor to extract the donor properties from extraction surfaces of the donors, and a property assignor to assign the donor properties to boundary surfaces of respective ones of the recipients, and a flow field generator to generate an output flow field for the second time step based on the recipients having the assigned donor properties.

Abstract: The present invention discloses systems and methods for the performance enhancement of rotary wing aircraft through reduced torque, noise and vibration. In one embodiment, a system includes a sail having an aerodynamic shape positioned proximate to a tip of the rotor blade. An actuator may be configured to rotate the sail relative to the blade tip. a A control system receives information from a rotorcraft system and commands the actuator to rotate the sail to a predetermined favorable rotor blade operating condition. In another embodiment, a method includes configuring the rotorcraft in a selected flight condition, communicating input signals to a control system operable to position sails coupled to tips of blades of a rotor assembly, processing the input signals according to a constraint condition to generate sail positional information, and transferring the sail positional information to the sail.