State file

The state file must be located in state directory (see see Project directory). A state file defines one or more aerodynamic states which are to be analysed. A simple example for a state file is shown below.

Flight state keywords

  • airspeed True airspeed (TAS) of the aircraft in meter per second
  • alpha Angle of attack in degrees
  • altitude Flight altitude as geometric height in meters
  • beta Side slip angles in degrees
  • density Air density in kilogram per meter³
  • mach Flight Mach number
  • rate_P Aircraft rotation rate about the body-fixed X-axis in radians per seconds
  • rate_Q Aircraft rotation rate about the body-fixed Y-axis in radians per seconds
  • rate_R Aircraft rotation rate about the body-fixed Z-axis in radians per seconds

The aerodynamic angles alpha and beta are measured relative to the body-fixed system

Aero-performance maps

PyTornado can perform batch analyses and create a so-called aero-performance map. In order to analyse multiple flight states, you can create a list of values for each flight state keyword (instead of using single numerical values). An example state file for an aero-performance map analysis is shown below.

{
    "aero": {
        "altitude": [0,   10e3, 10e3],
        "mach":     [0.2,  0.4,  0.4],
        "alpha":    [5.0,  5.0,  5.0],
        "beta":     [0.0,  0.0,  0.0],
        "rate_P":   [0.0,  0.0,  0.0],
        "rate_Q":   [0.0,  0.0,  0.0],
        "rate_R":   [0.0,  0.0,  0.0]
    }
}

In this example three separate flight states are computed, and for each analysis results can be saved separately. It is important that every list has an equal number of items. The first item of every list defines the flight state, the second item of every list defines the second flight state, etc. Notice that the flight state can be defined by any valid combination of airspeed, altitude, mach and density. Valid combinations are:

  • airspeed and density
  • airspeed and altitude
  • mach and altitude

For instance, if airspeed and density are used, mach and altitude can be omitted, or set to null.

Hint

Internally, PyTornado will run all computations using the airspeed and the air density. If you choose altitude as input, PyTornado will compute the air density and the speed of sound. PyTornado uses the ICAO Standard Atmosphere 1993 as the atmospheric model.

CPACS Aero-performance maps

Aero-performance maps defined in CPACS can also be evaluated using PyTornado. How to load CPACS defined aero-performance maps is described here: