Analysis of Crimped Connections Heat Transfer Coefficient Using Experimental and Numerical Determinations


In this paper is presented an analysis of the influ-ence of heat transfer coefficient on temperature values using numerical and experimental results. The research was car-ried out on a crimped connection used at electrical genera-tors manufacture. It was started by heating the crimped connection in AC regime at different electrical current in-tensities for obtaining the values of stabilised temperature. Then, the coefficient was calculated using two different me-thods. The first method, the analytical – experimental ap-proach, consists in calculation of heat transfer coefficient values using a relation obtained starting from thermal re-gime equilibrium. The second method, calculation – experi-mental approach, involves using a minimize function which can be implemented in MathCad. After that, coefficient values were introduced in numerical simulation in order to determine temperature values. The numerical model was developed in QuickField software starting from a coupled problem AC Magnetics – Steady State Heat transfer. At the beginning the AC magnetic problem was solved with the objective of obtainig the heat source which was introduced in Steady State Heat Transfer problem. Finally, by using numerical and experimental results, errors were calculated with the aim of determining the efficience of these two me-thods. It was then concluded that, for domains which in-clude electrical currents up to 1000 A, errors are relative small. But for high values of electrical currents another me-thod for heat transfer coefficient should be developed. images