Study of laminar single phase frictional factor and Nusselt number in In-line micro pin-fin heat sink for electronic cooling applications

•Mechanism of heat transfer in in-line elliptical pin-fin micro heat sink is studied.•A numerical model is developed and validated with in-house experimental results.•Cyclic nature of local heat transfer coefficient is observed.•Volume averaged analysis with suitable length scale for each parameter is used.•Correlations describing frictional factor and Nusselt number are proposed.