Fluid Flight

Flight Model

Fluid Flight calculates the aerodynamic forces on small segments of the wing and other surfaces, which are then processed by a physics engine. In the simplest case, aerodynamic coefficients could be calculated based on the angle of attack of the incoming airflow at each surface. In reality, these surfaces cause disturbances that alter the airflow, affecting other surfaces.

A wing with a finite span generates tip vortices as air moves from the high-pressure region below the wing to the low-pressure region above. This is a simplified explanation, as in reality, vorticity occurs wherever there is a difference in lift along the wingspan.

In Fluid Flight, this is modeled by calculating the vortices at the tips of the segments and then applying the disturbance to the other segments.

This is important for a realistic result because these disturbances (usually downwash) affect the flight characteristics in multiple ways. They cause induced drag and change the lift distribution and stall characteristics. For example, a wing with a rectangular geometry doesn't have a uniform lift distribution and stalls first in the middle and last at the wingtips because the vorticity is the strongest there, causing the most downwash, reducing the effective angle of attack (this is why the phrase "tip stall" is based on a myth, usually the tip stalls last).

blue vectors: disturbances / green vectors: lift / purple vectors: lift, stalled

Features

• Flexible input system
  Anything that Windows recognizes as a game controller (including many RC transmitters), mouse, and keyboard can be used for control.

• Environment
  There is a customizable dynamic skybox, wind, air density, and gravity.

• Instruments
  Basic flight instruments can be placed on the screen wherever you like.

• Replay
  Flights can be replayed in-game using relatively small replay files.

It is a work-in-progress project. Some key features are not yet fully implemented - for example, there is no scenery yet. If there is any progress, the Steam page will be updated.