Experimental and numerical analysis on thermo-hydrodynamic behavior of a mono-grooved micro heat pipe with branched condenser section

In this study, a novel branched condenser section micro heat pipe (MHP) is developed to improve heat transfer in conventional MHP. The branched mono-grooved MHP is investigated computationally and experimentally for hydrodynamic and thermal performance in small-scale electronic applications. A copper/water square crosssectional (Dh = 0.5 mm) mono-grooved MHP with branched condenser (30 mm each), adiabatic (30 mm), and evaporator (10 mm) sections, which resembles T-shape is modelled and simulated with the aid of gravity using VOF technique for tracking the interface in ANSYS-FLUENT & REG;2019 R1. The hydrodynamics behaviour of Tshaped mono-grooved MHP (T-MGMHP) showed liquid slug and vapor plug oscillated due to pressure difference between the condenser branches for different fill ratios, heat inputs and condenser condition. The oscillation is significant for fill ratios between 0.6-0.4, facilitates the improvement of condensate circulation and entrainment of evaporator. Experiments are performed to characterize the performance of T-MGMHP in vacuum to eliminate convective and radiative losses, exhibits reduced thermal resistance with the fill ratio ranges from 0.7 to 0.55. Numerical analogy is validated with experimental results of Wu et al., 1991, the computational and experimental thermal resistance of T-MGMHP exhibited consistent qualitative trend with negligible variance. This T-MGMHP capable of transporting maximum heat flux of 15-16.67 W/cm2 with the maximum evaporator temperature lower than 100 degrees C and the lowest thermal resistance occurred at 0.6 FR with heat input 1.25 W. This article insights into the heat transfer and fluid flow of the examined T-MGMHP.