Summary for: SimpleJacketThermalModel < ThermalModelElement

Class summary

SimpleJacketThermalModel Simple model for cooling jacket.

This class models lumped heat transfer from the boundary (normally stator OD) to the coolant, considering the two thermal resistance

  • surface to jacket, modelled by an equivalent interference gap consisting of air
  • jacket to coolant

For the latter, the dimensions of an individual cooling channel within the jacket are first computed with this.get_channel_data. The heat transfer coefficient from the channel wall to the coolant is then computed from the Nusselt number, channel hydraulic diameter, and the thermal conductivity of the coolant. Finally, as the thermal model only sees heat transfer on the (cylindrical stator outer) surface, this constant is multiplied by an appropriate factor to obtain the correct net heat transfer.

For manually setting the net heat transfer coefficient, setting this.heat_transfer_coefficient_total is sufficient.

Properties

.Nusselt_number Fudge factor.

.Reynolds_number Not used right now.

.channel_aspect_factor Channel width/heigth ratio

.channel_pitch Ratio of sum of channel widths to stator periphery

.SimpleJacketThermalModel/connection is a property.

.coolant_thermal_conductivity Defaults to water.

.h_channel Height of single cooling channel

.SimpleJacketThermalModel/heat_transfer_coefficient_jacket2coolant is a property.

.SimpleJacketThermalModel/heat_transfer_coefficient_total is a property.

.SimpleJacketThermalModel/heat_transfer_coefficient_yoke2jacket is a property.

.helix_length_factor Length factor.

The cooling channels are assumed helical. The net heat transfer coefficient is multiplied by the length factor, to reduce the behaviour into the 2D plane analysed.

.interference_gap_mm Equivalent airgap between stator and jacket

.SimpleJacketThermalModel/magnetic_model is a property.

.SimpleJacketThermalModel/radius is a property.

.SimpleJacketThermalModel/thermal_model is a property.

Methods

Class methods are listed below. Inherited methods are not included.

.frame to housing

.flow in SI units

.get_channel_data Get cooling channel spefications.

data = get_channel_data(this) returns a struct with the following fields

  • w_channel : width of single cooling channel
  • h_channel : height of cooling channel
  • A_channel : area of single channel
  • periphery : periphery of single channel
  • hydraulic_diameter : channel hydraulic diameter
  • number_of_channels : approximate number of cooling channels

.SimpleJacketThermalModel/initialize is a function.

initialize(this)