The universal motor, versatile and capable of running on both AC and DC sources, is utilized in various household appliances and power tools. This paper presents a featured methodology for analyzing a universal motor (UM) that does not have design data by extracting it via reverse engineering. These gained data were used to model the motor by Maxwell program and analyzing it by finite element method (FEM). Adopting the Maxwell program's drawing capability to design the square-shaped stator of a universal motor not part of the program library will also enable the Maxwell program to be widely used and unrestricted to use with particular motor designs. After modeling and solving the motor model, the performance characteristics of UM when operated with alternating current (AC) and direct current (DC) power supplies were investigated. The UM simulation results were compared with test results with good agreement. The success of a proposed methodology paved the way for the analysis of any electric motor included in the Maxwell program, even if this motor does not have design data.
Switched reluctance motor (SRM) is an electric motor works based on the reluctance torque produced due to the variation of the rotor pole position with respect to stator poles. This paper adopts a thermal analysis on a 4-phase, 8/6 pole, 550W, SRM. Lumped parameters thermal network method(LPTN) is used in this analysis based on a combination of RMXprt/Motor-CAD software, in two- dimensional(2D), steady-state, with different cooling methods, and with different loading conditions. Motor losses like core losses, copper losses, and mechanical losses are regarded as the heat sources in SRM which are calculated by RMXprt software. The thermal analysis achieved by Motor-CAD includes displaying the temperature distribution on different motor parts like stator winding, stator poles, stator yoke, rotor poles, rotor yoke, shaft, covers, and housing. The analysis results showed the increasing temperature distribution on different motor parts with increasing motor loading conditions. Also, this temperature distribution is recorded using three different cooling methods. The comprehensive thermal analysis applied in this work will assist the motor designer in choosing a better motor thermal design without needing to produce and test costly prototype motors.
Natural convection heat transfer in two-dimensional region formed by constant heat flux horizontal flat tube concentrically located in cooled horizontal cylinder studied numerically. The model solved using the FLUENT CFD package. The numerical simulations covered a range of hydraulic radius ratio (5, 7.5, and 10) at orientation angles from (0o up to 90o). The results showed that the average Nusselt number increases with hydraulic radius ratio, orientation angles and Rayleigh number. As well as enhancement ratio for Nusselt number at orientation angle 90o and hydraulic radius ratio 7.5 equal 24.87%. Both the fluid flow and heat transfer characteristics for different cases are illustrated velocity vectors and temperature contours that obtained from the CFD code. The results for the average Nusselt numbers are compared with previous works and show good agreement.