Temperature and Consumed Energy Predictions for Air-Cooled Interior Permanent Magnet Motors Driving Aviation Fans—Part 1: Mathematical Analytical Solutions for Incompressible Air Cases
Journal Article
14-12-01-0005
ISSN: 2691-3747, e-ISSN: 2691-3755
Sector:
Citation:
Ito, Y., Watanabe, T., Seki, N., Oyori, H. et al., "Temperature and Consumed Energy Predictions for Air-Cooled Interior Permanent Magnet Motors Driving Aviation Fans—Part 1: Mathematical Analytical Solutions for Incompressible Air Cases," SAE Int. J. Elec. Veh. 12(1):63-90, 2023, https://doi.org/10.4271/14-12-01-0005.
Language:
English
Abstract:
The increase in worldwide awareness of environmental issues has necessitated the
air transport industry to drastically reduce carbon dioxide emissions. To meet
this goal, one solution is the electrification of aircraft propulsion systems.
In particular, single-aisle aircraft with partial turboelectric propulsion with
approximately 150 passenger seats in the 2030s are the focus. To develop a
single-aisle aircraft with partial turboelectric propulsion, an air-cooled
interior permanent magnet (IPM) motor with an output of 2 MW is desired. In this
article, mathematical system equations that describe heat transfer inside the
target air-cooled IPM motor are formulated, and their mathematical analytical
solutions are obtained. From the results, the following predictions are made.
(1) In the heat exchanger, the external air should flow between a stator and the
internal air, and the flow direction of the external air should be opposite to
that of the internal air. (2) The internal air mass flow rate should be chosen
to maintain the turbulent internal flow through the heat exchanger. (3) The
internal air mass flow rate has the optimum value to minimize the rotor
temperature. (4) The rotor temperature increases with decreasing internal air
mass flow rate below the optimum value. (5) The rotor temperature increases with
increasing internal air mass flow rate beyond the optimum value. (6) The rotor
and stator temperatures are linearly proportional to the ambient temperature.
(7) The rotor temperature increases with decreasing ambient pressure. (8) An
increase in altitude causes a decrease in power consumption for both the
external air and internal air. (9) The most severe condition is the top-of-climb
condition, and the external and internal air mass flow rates should be chosen to
make the rotor temperature less than the maximum limit temperature of 100°C and
the stator temperature less than the maximum limit temperature of approximately
250°C.