Area Conversion
This module is used to convert areas between various units.
Convert area values between ft**2, in**2, m**2, km**2, sm**2 and nm**2.
def area_conv(Area, from_units=default_area_units, to_units=default_area_units):
"""
NOTE: The incoming value is first converted to ft**2, then it is converted to
desired return value.
"""
...
return converted area
NB: The units default to those specified in default_units.py
Examples:
Convert 1 ft**2 to inches**2, with ft\*\*2 already defined as the default units:
> area_conv(1, to_units = 'in**2')
144.0
Convert 288 square inches to square feet, with ft**2 already defined as the default units:
> area_conv(288, from_units = 'in\*\*2')
2.0
Convert 10 square metres to square inches:
> area_conv(1000, from_units = 'm**2', to_units = 'in**2')
1550003.1000061999
Density Conversion
This function is used to convert density values between e.g kg/m**3, slug/ft**3 and lb/ft**3.
def density_conv(Density, from_units, to_units):
"""
The incoming value is first converted to kg/m**3, then it is converted
to desired return value.
"""
...
return converted_density
NB: There are
NOdefault units. Both the from_units and the to_unitsMUSTbe specified.
Example:
Convert 1.225 kg per metre cubed to lb per foot cubed:
> density_conv(1.225, from_units = 'kg/m**3', to_units = 'lb/ft**3')
0.076474253491112101
Force Conversion
Convert force values between lb and N.
def force_conv(Force, from_units=default_weight_units, to_units=default_weight_units):
"""
The incoming value is first converted to N, then it is converted to the
desired return value.
"""
...
return converted_force
Length Conversion
Convert length values between ft, in, m, km, sm and nm.
def len_conv(L, from_units=default_length_units, to_units=default_length_units):
"""
The incoming value is first converted to ft, then it is converted to
desired return value.
The units default to those specified in default_units.py
"""
...
return converted_length
Examples:
Convert 5280 ft to statute miles, with feet already defined as the default units:
> len_conv(5280, to_units = 'sm')
1.0
Convert 1 nautical mile to feet, with feet already defined as the default units:
> len_conv(1, from_units = 'nm')
6076.1154855643044
Convert 1000 metres to kilometres:
> len_conv(1000, from_units = 'm', to_units = 'km')
0.99999999999999989
Power Conversion
Convert power values between horsepower, ft-lb/mn, ft-lb/s, watts, kilowatts, BTU/hr and BTU/mn.
def power_conv(P, from_units=default_power_units, to_units=default_power_units):
"""
The incoming value is first converted to hp, then it is converted to the
desired return value.
"""
...
return converted_power
The units default to those specified in default_units.py
Pressure Conversion
Convert pressure values between inches of HG, mm of HG, psi, lb/ft^2, hpa and mb.
def press_conv(P, from_units=default_press_units, to_units=default_press_units):
"""
The incoming value is first converted to Pa, then it is converted to
desired return value.
The units default to those specified in default_units.py
"""
...
return converted_pressure
Examples:
Convert 1013.25 hpa to default pressure units:
> press_conv(1013.25, from_units = 'hpa')
29.921331923765198
Convert 29.9213 default pressure units to mm of HG:
> press_conv(29.9213, to_units = 'mm HG')
760.00128931459176
Convert 2116.22 lb per sq. ft to lb per sq. inch:
> press_conv(2116.22, from_units = 'psf', to_units = 'psi')
14.695973160069311
Speed Conversion
Convert speed values between kt, mph, km/h, m/s and ft/s.
def speed_conv(S, from_units=default_speed_units, to_units=default_speed_units):
"""
The incoming value is first converted to kt, then it is converted to
desired return value.
The units default to those specified in default_units.py
"""
...
return converted_speed
Example:
Convert 230 mph to kt:
> speed_conv(230, from_units = 'mph', to_units = 'kt')
199.86453563714903
Temperature Conversion
Converts absolute temperature values between deg C, F, K and R.
NOTE: This function should NOT be used for relative temperature conversions, i.e.
temperature differences.
def temp_conv(T, from_units=default_temp_units, to_units=default_temp_units):
"""
The incoming value is first converted to deg K, then it is converted to
desired return value.
The units default to those specified in default_units.py
"""
return converted_temperature
Examples:
Convert 32 deg F to deg C, with deg C as the default units:
> temp_conv(32, from_units = 'F')
> 0.0
Convert 100 deg C to deg F, with deg C as the default units:
> temp_conv(100, to_units = 'F')
> 212.0
Convert 59 deg F to deg K
> temp_conv(59, from_units = 'F', to_units = 'K')
> 288.14999999999998
Volume Conversions
Convert volume values between USG, ImpGal (Imperial gallons), l (litres), ft**3, in**3, m**3, km**3, sm**3 and nm**3.
def vol_conv(V, from_units=default_vol_units, to_units=default_vol_units):
"""
The incoming value is first converted to ft**3, then it is converted to
desired return value.
The units default to those specified in default_units.py
Examples:
"""
return converted_volume
Convert 1 cubic foot to US gallons, with cubic feet already defined as the default units:
> vol_conv(1, to_units = 'USG')
7.4805194804946105
Convert 1 Imperial gallon to cubic feet, with cubic feet already defined as the default units:
> vol_conv(1, from_units = 'ImpGal')
0.16054365323600001
Convert 10 US gallon to litres:
> vol_conv(10, from_units = 'USG', to_units = 'l')
37.854117840125852
Weight Conversion
Convert weight values between lb and kg.
Purists will yell that lb is a unit of weight, and kg is a unit of mass.
Get over it!!!!!
def wt_conv(W, from_units=default_weight_units, to_units=default_weight_units):
"""
The incoming value is first converted to kg, then it is converted to the
desired return value.
The units default to those specified in default_units.py
"""
return converted_weight
AVGAS Conversion
Convert aviation gasoline between units of lb, US Gallon (USG), Imperial Gallon (Imp Gal), litres (l) and kg, assuming nominal density for aviation gasoline of 6.01 lb per USG.
Note: it was difficult to find authoritative values for aviation gasoline
density. Conventional wisdom is that aviation gasoline has a density of
6 lb/USG. The Canada Flight Supplement provides densities of:
temp density density density
(deg C) (lb/USG) (lb/ImpGal) (lb/l)
-40 6.41 7.68 1.69
-20 6.26 7.50 1.65
0 6.12 7.33 1.62
15 6.01 7.20 1.59
30 5.90 7.07 1.56
However, the Canada Flight Supplement does not provide a source for its
density data. And, the values for the different volume units are not
completly consistent, as they don't vary by exactly the correct factor.
For example, if the density at 15 deg C is 6.01 lb/USG, we would expect
the density in lb/ImpGal to be 7.22, (given that 1 ImpGal = 1.201 USG)
yet the Canada Flight Supplement has 7.20.
The only authoritative source for aviation gasoline density that was
found on the web was the \"Air BP Handbook of Products\" on the British
Petroleum (BP) web site:
<http://www.bp.com/liveassets/bp_internet/aviation/air_bp/STAGING/local_assets/downloads_pdfs/a/air_bp_products_handbook_04004_1.pdf>
It provides the following density data valid at 15 deg C (the BP document
only provides density in kg/m**3 - the density in lb/USG were calculated
by Kevin Horton):
Avgas density density
Type (kg/m**3) (lb/USG)
80 690 5.76
100 695 5.80
100LL 715 5.97
The available aviation gasoline specifications do not appear to define an
allowable density range. They do define allowable ranges for various
parametres of the distillation process - the density of the final product
will vary depending on where in the allowable range the refinery is run.
Thus there will be some variation in density from refinery to refinery.
This function uses the 15 deg C density values provided by BP, with the
variation with temperature provided in the Canada Flight Supplement.
The grade may be specified as \"80\", \"100\" or \"100LL\". It defaults to
\"100LL\" if it is not specified.
def avgas_conv(
AG,
from_units=default_avgas_units,
to_units=default_avgas_units,
temp=15,
temp_units="C",
grade="nominal",
):
"""
The units default to those specified in default_units.py
The temperature defaults to 15 deg C if it is not specified.
"""
return converted_avgas