Lithium Air Regional Jet Sizing

Introduction

The purpose of this tutorial is to highlight some of SUAVE’s more exotic propulsion system capabilities. This tutorial assumes that the user has completed the Boeing 737-800 tutorial, and has some familiarity with SUAVE’s propulsion system data structures.

Baseline Case

Open the file called “tut_lithium_air_jet_sizing.py” in a text editor or IDE.

Look over the plots, to gain a feel for the various idiosyncrasies of the design. Note the significant rise in aircraft mass, as a result of the lithium-air batteries.

li air mass


    battery = configs.base.energy_network['battery']
    battery.specific_energy=2000*Units.Wh/Units.kg
    battery.specific_power =.67*Units.kW/Units.kg

Run the script (python tut_lithium_air_jet.py).

Now try changing the motor efficiency from .95 to .9 and running the script (line 513).


    net.nacelle_diameter  = ducted_fan.nacelle_diameter
    net.engine_length     = ducted_fan.engine_length    
    net.number_of_engines = ducted_fan.number_of_engines
    net.motor_efficiency  =.95

Note the sensitivity of vehicle energy and mass requirements to these various propulsion system assumptions.

Now try changing the cruise range of the aircraft (line 868, segment.distance).


    segment = Segments.Cruise.Constant_Speed_Constant_Altitude()
    segment.tag = "cruise"

    # connect vehicle configuration
    segment.analyses.extend( analyses.cruise )

    # segment attributes
    segment.atmosphere = atmosphere
    segment.planet     = planet

    segment.air_speed  = 230.
    segment.distance   = 1947. * Units.nmi

Try changing other parameters (e.g. specific power, cruise altitude), and observe their effects on the overall design.