Engee documentation

Non-Standard Day 310

MIL-HDBK-310 atmospheric model.

blockType: SubSystem

non standart day 310

Path in the library:

/Aerospace/Environment/Atmosphere/Non-Standard Day 310

Description

Block Non-Standard Day 310 implements mathematical representation of the atmospheric model from fragments of climatic data up to geometric height of 80 km in accordance with MIL-HDBK-310 standard on global air environment, generates values of temperature, pressure, density and sound speed for a given geometric height .

The Non-Standard Day 310 unit is similar to the COESA Atmosphere Model unit . The Non-Standard Day 310 block realises mathematical representation of the atmospheric model using experimental data, and the COESA Atmosphere Model block - using formulas.

The Non-Standard Day 310 block works in SI units.

Limitations

  • Below an altitude of 0 m and above an altitude of 80000 m, the values of atmospheric parameters remain unchanged. The discrete atmospheric model (Envelope value for the Atmospheric model type parameter) has a few exceptions where atmospheric parameter values remain unchanged below 1 km and above 30000 m. This is due to the lack of relevant data in the MIL-HDBK-310 standard.

  • Climatic data for regions south of the 60th parallel of southern latitude are not available in MIL-HDBK-310.

  • MIL-HDBK-310 provides data in SI units.

Entry

h (m) - geometric height
scalar | vector

Geometric height, m.

Data types: Float64.

Output

T (K) - temperature
scalar | vector

Temperature, K.

Data types: Float64.

a (m/s) - speed of sound
scalar | vector

Speed of sound, m/s.

Data types: Float64.

P (Pa) - pressure
scalar | vector

Pressure, Pa.

Data types: Float64.

ρ (kg/m3) - air density
scalar | vector

Density of air, kg/m³.

Data types: Float64.

Parameters

Atmospheric model type - atmospheric model type
Profile (by default) | Envelope

Atmospheric model type:

  • Profile - continuous, based on real atmospheric profiles that are related to the limit values of atmospheric parameters at a given altitude; recommended for modelling aircraft flight during which their altitude varies significantly, or when the full effect of the atmosphere on the aircraft needs to be modelled.

  • `Envelope' - discrete, based on the limit values of atmospheric parameters at each altitude; recommended for modelling the flight of aircraft performing only horizontal flight without significant changes in altitude.

Extreme parameter - limit parameter
High temperature (By default) | Low temperature | High density | Low density | High pressure | Low pressure

A parameter of the atmosphere that has a limit value:

  • High temperature - high temperature.

  • Low temperature - low temperature.

  • High density - high density.

  • Low density - low density.

  • High pressure - high pressure.

  • Low pressure - low pressure.

Dependencies

The High pressure and Low pressure options are only available when the Envelope atmosphere model type is selected.

Frequency of occurrence - frequency of occurrence
1% (by default) | Extreme values | 5% | 10% | 20%.

Percentage of the time period when values can be repeated.

Dependencies

  • The 1% and 10% values are always available.

  • The Extreme values, 5% and 20% are only available when the Envelope atmospheric model type is selected.

*Altitude of extreme value` - geometric altitude
5 km (16404 ft) (By default) | 10 km (32808 ft) | 20 km (65617 ft) | 30 km (98425 ft) | 40 km (131234 ft)

The geometric altitude at which the atmospheric parameter takes on a limiting value.

Dependencies

This parameter is only available when Profile atmosphere model type is selected.