Heat Transfer In Electrical Machine: A Case Study
Future design of Aircraft and Automotive needs innovation in propulsion mechanism which are based on
electrical mode of operation. More Electric mobility needs a compact high performance electric motor which will assure
long operating life with maximum efficiency. Electric motor design needs a multidisciplinary approach including efficient
mechanism for heat transfer. The present study reports a Combined Computational fluid dynamics and network approach
(CCFDN), applied to the problem of cooling a 1200kW traction alternator. In this combined approach, analysis is first
performed using equivalent, lumped thermal network with a simplified circuit aimed at delivering fast, design class results.
CFD calculations are next performed to estimate thermal resistances, which are used as input to the thermal networks.
Iterative procedure is adopted for solving the network. Results are presented in terms of temperatures at different locations of
the device for three cases: one without forced cooling (fan), and second with a fan. The maximum temperature values
obtained in the second case is found to be 2.1 times lower than the values obtained in the first case. Results are compared
with pure network approach using empirical correlations and with pure conjugate analysis using CFD. The present CCFDN
approach avoids using empirical relations, yet much faster than the full conjugate CFD analysis.