Determination of Heat Transfer Coefficient for the Air Forced Cooling Over a Flat Side of Coil

Abstract

The paper deals with the analytical and experimental determination of the forced convection heat transfer coefficients over the flat coil module. In the analytical part, the forced convection coefficients at different wind speeds are calculated based on various known equations of the forced convection heat transfer coefficient with unheated starting length. The experimental part presents the description of the test: loading the coil with DC current and measurements of the coil temperatures with thermal sensors while it was inside a wind tunnel. Based on the measurement, the convection coefficients were determined. In the final part, the experimental and analytical results are compared. It is found that the accuracy of the analytical results is more precise in highly turbulent flows.

Analytical thermal model and flow network analysis suitable for open self‐ventilated machines

“…These thermal drawbacks in an electrical machine are adjusted by selecting a proper cooling method. One of the common cooling methods is a forced air method [2]. In this method, the fan or blower produced the airflow through the machine or over the housing of the machine [3].…”