## 1 Introduction and Literature Review
The TPMS structures examined were gyroid, diamond, and Iwp, and their performance was compared with a fins structure. An experiment was conducted to validate the accuracy of the numerical simulation. The results showed a good agreement between the simulation and experiment with an error margin of less than 6%. Among the three TPMS structures, TPMS-Diamond was concluded to have the best convective heat transfer performance due to its geometric structure without \"holes\", thus causing the wall to disturb the fluid more and enhance heat transfer. [PERSON] et al. [14] experimentally investigated the thermal performance of a microchannel heat sink (MCHS) using a nanofluid. The heat dissipation performance of pure water and the nanofluid on MCHS was studied. It was reported that microchannel heat sinks can be widely used in electronic devices to provide high heat dissipation rates and optimal performance with durability. [PERSON] et al. [15] examined flow and heat transfer in porous media. Porous structures created using lattice-shaped TPMS (diamond, I-WP, primitive, and gyroid) were analyzed. The research focused on the effects of shape morphology, tortuosity, micro-porosity, and effective porosity on the permeability and inertial drag factor. Using numerical simulations, conductivity and inertial drag coefficient values were determined for different flow regimes and structure types. The results provide essential insights for understanding and optimizing flow behavior in porous media. [PERSON] et al. [16] aimed to improve the performance and reduce the cost of heat exchangers in oil refineries. Analyses using two different oil-based nanofluids (MgO-SAE10 and ZnO-SAE10) revealed significant improvements in the thermal-hydraulic performance of heat exchangers, ranging from 84.78% to 107.68%. The findings demonstrated that using nanofluids in heat exchangers is advantageous in terms of both performance and cost. These research efforts indicate that minimal surfaces, particularly TPMS structures, have a wide range of applications in heat transfer systems for developing more efficient designs. The effects of different fluids, materials, and structural designs on heat transfer performance are being examined in detail, providing valuable insights for future advancements in this field. The literature review shows that the experimental measurement of the TPMS structure in heat removal is not well spread. Many numerical modelling papers have been published, but experimental measurement is crucial in investigating the importance of this class of porous structure. [PERSON] et al. [17] recently showed the importance of implementing this new class of TPMS porous structure for heat enhancement. As stated by the authors, one of the unique experimental findings is the uniformity of the temperature distribution. That means the buildup of the thermal boundary layer is minimal. This is due to the connectivity channels, which, in some cases, break this boundary layer. In this article, [PERSON] et al. (2017) used distilled water as the cooling fluid and investigated experimentally different classes of TPMS structures having different porosity. As shown in the review, no one has yet conducted experimental measurements of TPMS performance using a nanofluid. Thus, the uniqueness of this paper is its experimentation using nanofluids in the presence of a triply periodic minimal surface porous structure. Section 2 presents the experimental setup used in this work. Section 3 concentrates on the numerical modelling compared to the experimental data. The results are presented in Section 4. And finally, the conclusion is in Section 5.