Flat miniature heat pipe with sintered porous wick structure: experimental and mathematical studies.

• Effect of tilt and length on porous miniature heat pipes thermal performance is investigated experimentally. • Thermal resistance network of 1D of miniature heat pipes with fin is detailed for thermal modelling. • Prediction of evaporation and condensation heat transfer coefficients using experimental results. • Effect of adiabatic length on capillary pressure of the two studied heat pipes using the developed hydraulic model. • Effect of porous media parameters on thermal resistance and heat pipes thermal performance and evaluation of optimal porosity. Miniature heat pipes are considered as an innovative solution able to dissipate high heat fluxes with low working fluid charge, temperature control, and operating with minimum energy consumption and less noise. In this paper, results show that tilt ranging [10°:60°] has not an impact on heat transfer meanwhile the system thermal resistance is the lowest at horizontal position. A theoretical analysis on heat pipe thermal performance has been carried out based on experimental data by predicting heat pipe evaporation and condensation heat transfer coefficient. The measured heat transfer coefficients are close to the predicted results with a mean deviation less than 10%. A hydraulic mathematical model is developed and shows a good agreement with Kaya's study using water as working fluid. This work comprises a parametric study that investigates the effect of particles size, porosity, permeability, heat pipe length on heat transfer and capillary pressure. The obtained results show that the heat pipe operating temperature rises when particles size increases from 1 μ m to 90 μ m and the optimum porosity range is between [10%–40%]. [ABSTRACT FROM AUTHOR]