الفهرس 
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Abstract
The present study reports the experimental investigation of pool boiling heat transfer at the nucleate region. Based on passive techniques to improve the heat transfer coefficient. The microstructure of copper heating surfaces is modified in various ways. The microstructure surfaces are made using a wire-cutting machine to carve channels into the heating surface. Utilizing laser-processed surfaces on the heating surface, it is necessary to make cavities of various diameters within the made media. Surface roughness (Ra=0.58 m) was the finest grading of sandpaper, through which we obtained the most significant improvement. It was applied to the two samples with channels and the other with a diameter of 300 μm to get better results. Microstructured surfaces’ heat transfer coefficients (HTC) are estimated experimentally using pure water as the pool boiling liquid. The tests are conducted at atmospheric pressure in a saturated pool boiling state with a heat flux ranging from 50 to 580 kW/m2.
The results of an experimental investigation of heat transfer during pool boiling on microstructure copper heating surfaces are presented, The results showed that a maximum improvement of 51% - 92% was obtained using composite surface modification technology by forming a microscopic structure on the surface of the heat source.